AN ANTHROPOLOGICAL STUDY OF THE ABO BLOOD GROUP DISTRIBUTION AMONGST THE YORUBA OF NIGERIA BY BOLA BABATUNDE ADEKOYA B.Sc. Zoology Honours (Ibadan) M.Sc. Archaeology (Ibadan) A THESIS IN THE DEPARTMENT OF ARCHAEOLOGY AND ANTHROPOLOGY SUBMITTED TO THE FACULTY OF SCIENCE IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY UNIVERSITY OF IBADAN, IBADAN, NIGERIA JUNE, 1994. UNIVERSITY OF IBADAN LIBRARY ii -A ABSTRACT Twenty-five (25) sub-groups of the Yoruba language sub-family in Nigeria were identified based on such similarities as: territory, dialect, descent, cultural and economic ties. The ABO blood group samples and records of the identified Yoruba sub-groups were analysed and evaluated. These Yoruba sub-groups included: Akoko, Akure, Awori, Bunu, Egba, Egbado. Ekiti, Eko, Ibarapa, Ibolo, Ife, Igbomina, Ijebu, Ijesa, Ijumu, Ikale, Ilaje, Ilorin, Kabba, Ondo, Owo, Owu, Oyo, Remo and Yagba. Frequency distribution and percentiles of the ABO blood groups in each Yoruba sub-groups were determined through statistical analysis and subjected to X2 distribution analysis to detect deviation significance levels about the expected mean of ABO blood groups for the Yoruba language sub-family. The majority of the individual blood group types within the Yoruba sub-groups were of the type 'O'. Percentiles and frequencies for this blood group type for each Yoruba sub-group exhibited two distinct mean pulses. The mean percentiles for the type 'O' blood group were 51.6% and 55% with mean frequency values of 0.718 and 0.742 respectively, indicating the presence of two dialect groups within the Yoruba UNIVERSITY OF IBADAN LIBRARY iii language sub-family. The Yoruba sub-groups hereby identified from the ABO blood sample analysis and subseguently classed into two dialect groups coincide with the "i" and "u" linguistic dialect areas into which the Yoruba territory of Nigeria is divided, thus confirming the existence of a definite anthropological divide of the Yoruba language sub-family. UNIVERSITY OF IBADAN LIBRARY iv ' y ACKNOWLEDGEMENTS I acknowledge with great thanks to God, the assistance and varied support of the following: My Supervisor: Prof. B.W. Andah for consistent guidance, critique and considerable assistance on literature and analytical options throughout the duration of the work. My co-supervisor, Dr. B . A. Ogunsanwo for incessant interest, professional inputs and thorough preparations on haematological techniques necessary to see the research work to fruition. My laboratory guides, Messers Idris Salihu and Bola Oduniyi for enabling me to acquire some nodding acquaintance of basic haematological (laboratory) methods within the shortest possible time. My loving wife, Sr.(Mrs.) F.A. Adekoya for her understanding and ebullient enthusiasm in assisting the progress of the work all through its duration. Prof. (Mrs.) M .A . Sowunmi, for critique, gift of literature and encouragement. Prof. S. Afolabi Toye, for literature assistance and information on the sub-groups of the Kwara Yoruba. Dr. J.O. Sanwo, on the genetical aspects of blood group inheritance in man and financial support. Dr. D.A, Aremu for literature and information on the sub-groups of Kwara Yoruba. Dr. P.A. Oyelaran for Kogi Yoruba materials and history. Dr & Mrs. Jimi Adesina for synthesis, critique, financial support and computer analysis. Dr. (Mrs.) C.Y. Jeje for structural UNIVERSITY OF IBADAN LIBRARY V critique and support. Dr. Archibong 0. Ekpo (G.Boss) for consistent support and multivariate assistance. Chief Bisi Rodipe (Bisrod) for financial support and encouragement. Dr. & Dr(Mrs) P .A. Araoye for assistance on sampling at Ilorin. Sr. (Mrs.) 0 Adeoye for assistance on the sampling of the Ibolo, Igbomina and Yagba sub-groups. Prince A. Sulu-Gambari for information on the settlement history of the Ilorin sub-group. Sr.(Mrs.) Toyin Oworu for information on the settlement history of the Remo sub-group and incessant stationery assistance throughout the duration of the work. Dr. & Mrs O.Oyewo for the assistance on the Ibolo. Mr. 0. Moody for information and literature on the Yagba sub-group. Engr. & Sr. (Mrs.) Oguntusin for considerable financial support and encouragement.Mr. G.O. Bakare for support and assistance on the history of the Ibarapa sub-group. Mr Paul Bolorunduro for assistance and information on the Ijumu, Kabba, Yagba and Bunu sub­ groups. Mrs Lola Salihu for the assistance on the sampling of the Oyo sub-group. Mrs. C.O. Oyebade for the sampling of the Ibarapa sub-group. Engr. & Sr. (Mrs.) Jimi Omoliki for accommodation, support and encouragement. Dr. (Mrs.) K.O. Ekpo for encouragement and structural critique. Mr. & Mrs S.A.M. Adebowale for support and UNIVERSITY OF IBADAN LIBRARY VI goodwill. Messers Musa Kadzai, Jerome Afeikhena, Kayode Jagun for mathematical analysis, statistical analysis and support respectively.Mrs. 0.Elliot and Mrs. G.T. Omole for varied support and assistance. Messers Kunle Ogunkoya and Kunle Odufuye for the sampling of the I lor in sub-group. Engr. and Mrs P.B. Sanu for literature recoveries from Britain, support and goodwill. Mrs. O.A. Olawunmi for documentation support. Mrs. R.O. Komaiya, Mrs 0 Ajayi, Mrs. Dunni Sowole and Mr Olu Olaoyenikan for documentation work. Mr & Mrs 0 Dosunmu for literature support. Dr & Mrs K.B. Olurin for statistical analysis, structural critique and encouragement. Dr. and Mrs G.N. Ugwuzor for encouragement. Mr & Mrs 0 Obayeju for financial and moral support throughout the duration of the research period. Mr. B. Oyewo for assistance at the U.C.H. blood bank, Ibadan. Miss Kehinde Odufuye for communication support and incessant assistance. Sr. (Mrs.) W. Olabisi Odusote for encouragement. Miss T.O. Ayansanwo for support and goodwill. Miss F.O.A. Ajayi for support and consistent literature search. Dr. O.A Sodeinde for considerable assistance on bio-statistics and structural critique. For literature search and recoveries made from overseas, I thank Madam M.A. Odufuye (U.S.A.),Mr & Mrs Dele Oladoja (California, U.S.A.) Engr. Wale Odufuye (Chicago, U.S.A.), Kunle and Pelumi Odufuye (Britain) and Engr. Folorunso Oladeinde UNIVERSITY OF IBADAN LIBRARY vii (Britain). I am particularly grateful to Mr Tunde Adeyemi (Temple and Golders, Itamogiri, Ijebu Imushin) for literature support on the Owu sub-group. Similar thanks are due to: Mr. & Mrs Mojisola Oyenuga (N.T.C., Ibadan) for consistent varied support. Dr. C.A. Folorunso for incessant literature support and encouragement; Dr. 0.A. Ayinla for interest and profound goodwill; Dr. & Mrs. Temitayo Jaiyesimi for assistance and goodwill; Dr. & Mrs Segun Olunuga for literature support and goodwill. Special cognisance is taken of the assistance of the numerous staff of blood banks at the State hospitals, and health posts of the Yoruba sub-groups sampled. For the material, financial and varied assistance from many family members, relations and friends too numerous to mention here, I am very grateful. UNIVERSITY OF IBADAN LIBRARY CERTIFICATION I certify that this work was carried out by Bola Babatunde, Adekoya in the Department of Archaeology and Anthropology, University of Ibadan, Ibadan, Nigeria. (Supervisor) Prof. B.W. Andah, & A . (Lond.) ;M.Phil. (Lond.); Ph.D (Berkeley) Professor, Department of Archaeology and Anthropology University of Ibadan 1 Zoo-Supervisor) D^/ B.A. Ogunsanwo M.B.B.S. (Ibadan); F.M.C. (Path), F.W.A.C.P. Acting Head, Department of Heamatology, University College Hospital, Ibadan. JUNE, 1994 UNIVERSITY OF IBADAN LIBRARY IX DEDICATION To my Son, BUNMI BABAJIDE ADEKOYA in acknowledgement of his reflection of God's love UNIVERSITY OF IBADAN LIBRARY X TABLE OF CONTENTS Page TITLE i ABSTRACT ii ACKNOWLEDGEMENTS iv CERTIFICATION viii DEDICATION ix TABLE OF CONTENTS X LIST OF FIGURES xiii LIST OF TABLES xvii LIST OF APPENDICES xviii CHAPTER ONE: INTRODUCTION 1 General Background 1 The Importance of ABO Blood Group Study 1 Language as Discriminant 5 ABO Blood Groups: Anthropological Works 8 Aims of Study 13 Scope of the Study 16 The Study Location Area: Territory and Sub-groups' Locations 24 CHAPTER TWO: LITERATURE REVIEW 27 Earlier Work on the Yoruba and Yorubaland 27 Linguistics 27 Archaeology 35 History 38 Yoruba History 42 History of Yoruba Sub-groups 44 UNIVERSITY OF IBADAN LIBRARY xi CHAPTER THREE: BIOLOGICAL METHODS AND ANALYSIS 86 Biological Methods in Studying Human Groups 86 Biological Data in West Africa 86 ABO Blood Group as marker in population studies 89 ABO Blood Group: Antigens and Antibodies 89 ABO Grouping Data of the Yoruba: Findings 97 Methods of Analysis 100 ABO Blood Grouping: Principles and Procedures 102 Statistical Analysis 107 CHAPTER FOUR: RESULTS OF THE ABO BLOOD GROUP ANALYSIS OF THE YORUBA SUB-GROUPS 112 Blood Groups: Distribution, Percentiles, and Gene Frequencies 112 Blood Group Maps 112 Blood Groups in Samples of Yoruba Sub-Groups 112 Percentiles of Blood Groups 116 Gene Frequencies of Blood Groups 118 Analysis of Variance (Anova) Results: Blood Group Percentiles 120 Analysis of Variance (Anova) Results: Blood Group Gene Frequencies 126 Chi-Square (Matrix) Values for the Significance of Difference in the ABO Blood Group Distribution in the Yoruba Sub-groups 136 Bar charts of the Blood Group Values of the Yoruba Sub-groups 133 CHAPTER FIVE: DISCUSSION OF THE RESULTS OF THE ABO BLOOD GROUPING OF THE YORUBA SUB GROUPS 142 Dominance of Blood Group 'O' 142 Two Yoruba Dialect Groups 142 Biological Partition 144 Correlation of Biological and Linguistic Evidences 145 Anthropological Divide of the Yoruba Sub-Family 145 Negroid Marker: Blood Group XB' 147 Dilution Influence: Gene - A trends 149 UNIVERSITY OF IBADAN LIBRARY Xll ' Occurence of Cancer of the Stomach 151 Influences of Boundary Yoruba Sub-Groups 153 Higher Tendency for the Occurence of Ulcer 155 Genetic variation within the Yoruba Dialect Groups 155 Chi-Square Martix Analysis 157 Partition Into Two Dialect Groups 161 Varying Values of Significant Differences 165 Order of Sub-groups Based on X2 Values 165 Partition of Yoruba Sub-Groups Based on Anova Results 171 Overlaps Within the Anova Results 173 Blood Group 'B' Distribution: Negritude 174 Blood Group 'A' Distribution: Cancer 175 Blood Group '0' Distribution: Ulcer and Dilution 175 Overlaps and Yoruba Sub-Groups' Boundaries 176 Ife and the Advent of the "i" -dialect Group 176 Possible Derivation of Yoruba Dialect Groups 178 Biological Implications of Intrusions at Ife 180 The Place of Oduduwa 180 CHAPTER SIX: SUMMARY AND CONCLUSIONS 182 Summary of the Discussions of Results 182 Dominance of Blood Group 'O' 182 Two Yoruba Dialect Groups 182 Blood Group 'B' Distribution: Measure of Negritude 183 Blood Group 'A' Distribution: Cancer and Dilution 183 Boundary Effects Between Yoruba Sub-Groups 184 Blood Group '0' Distribution: Ulcer Tendencies 184 Genetic variation within the Yoruba 185 Sources of Derivation of Yoruba Dialect Groups 186 The Primacy of Ife and the Place of Oduduwa 188 Conclusions 190 '«* REFERENCES 193 APPENDICES 206 UNIVERSITY OF IBADAN LIBRARY xiii LIST OF FIGURES Fig 1: Nigeria (Ethnic Groups) Showing Yorubaland 2 Fig 2 : Yorubaland Showing Sub-Groups 4 Fig 3 : Biochemical Formulae of Antigens 7 Fig 4: Antigen-Antibody Reactions 9 Fig 5: Kogi State showing Yoruba Sub-Groups 14 Fig 6: Kwara State showing Yoruba Sub-Groups 16 Fig 7: Lagos State showing Yoruba Sub-groups 18 Fig 8: Ogun State showing Yoruba Sub-Groups 21 Fig 9: Ondo State showing Yoruba Sub-Groups 23 Fig 10: Osun State Showing Yoruba Sub-Groups 26 Fig 11: Oyo State showing Yoruba Sub-groups 28 Fig 12: Yorubaland: Showing Major Dialect Areas (After Oduyoye) 30 Fig 13: Linguistic Map of Africa (After Greenberg) 33 Fig 14: Peoples around the Niger Delta: As at the 12th century (After D.T. Niane) 41 Fig 15: Yoruba Territory Between 1100 - 1500 A.D. (After Ryder) 43 Fig 16: Nigeria (Ancient States) in the 16th century (After Lafene) . 45 UNIVERSITY OF IBADAN LIBRARY xiv 17: Nigeria (Ancient States) By 17th - 18th Century (After Ajayi & Espie) 47 18: Yorubaland and nearby states before 1800 A.D.(After Isichei). 49 19: Map of Africa showing Egypt, Nubia and Arabia 51 20: Multiple Bar chart of ABO Blood Group Distribution (in Yoruba sub-groups) 113 21: Multiple Bar Chart of ABO Blood Group Distribution (Dialect Groups 115 22: Multiple Bar Chart of ABO Blood Group Percentiles: In Dialect Groups 117 23: Bar charts of ABO Blood Group Gene Frequencies: In Dialect Groups 119 24: Bar Charts of Blood Group 'A' in Samples: In Dialect Groups 121 25: Bar Charts of Blood Group 'B' in Samples: In Dialect groups 123 26: Bar Charts of Blood Group 'AB' in samples: In Dialect Groups. 125 27 Bar Charts of Blood Group 'O' in Samples: In Dialect Groups. 127 28 Bar Charts of blood Group 'A' (Percentiles) In Dialect Groups 129 29 Bar Charts of Blood Group 'B' (Percentlies) In Dialect Groups 131 30 Bar Charts of Blood Group 'AB' (Percentiles) In Dialect Groups 133 UNIVERSITY OF IBADAN LIBRARY XV Fig: 31 Bar Charts of Blood Group 'O' (Percentiles) In Dialect Groups 135 Fig: 32 Bar Charts of Blood Group 'A' (Gene Frequencies) In Dialect Groups. 137 Fig: 33 Bar Charts of Blood Group 'B' (Gene Frequencies) In Dialect Groups 139 Fig: 34 Bar Charts of Blood Group 'AB' (Gene Frequencies In Dialect Groups 141 Fig: 35 Bar Charts of Blood Group 'O' (Gene Frequencies) In Dialect Groups 143 Fig: 36 Comparative Average Percentiles and Frequencies of Blood Group 'A' In Dialect Groups 146 Fig: 37 Comparative Average Percentiles and Frequencies of Blood Group 'B' In Dialect Groups 148 Fig: 38 Comparative Average Percentiles and Frequencies of Blood Group 'AB' In Dialect Groups 150 Fig: 39 Comparative Average Percentiles and Frequencies of Blood Groups 'O' In Dialect Groups 154 Fig: 40 Blood Group Map of Yoruba Sub-Groups: Gene 'A' 156 Fig: 41 Blood Group Map of Yoruba Sub-Groups Gene 'B" 158 Fig: 42 Blood Group Map of Yoruba Sub-Groups: Gene 'AB' 160 Fig: 43 Blood Group Map of Yoruba Sub-Groups: Gene '0' 162 UNIVERSITY OF IBADAN LIBRARY XVI Fig: 44 Blood Group Map of Yoruba Dialect Groups: Gene 'A' 164 Fig: 45 Blood Group Map of Yoruba Dialect Groups: Gene 'B' 166 Fig: 46 Blood Group Map of Yoruba Dialect Groups: Gene 'AB' 168 Fig: 47 Blood Group Map of Yoruba Dialect Groups: Gene 'O' 170 Fig 48 Yorubaland: Showing Dialect Groups (Based on Blood Groups' Partitions) 172 UNIVERSITY OF IBADAN LIBRARY xvii LIST OF TABLES Table 1: Yoruba Sub-Groups: Locations and Major Towns 20 Table 2: Classification of African Languages (After Greenberg, 1963) 32 Table 3: Summary of Archaeological Dates of Sites Related to Yorubaland 37 Table 4 : ABO Blood Group Antigens and Antibodies 91 Table 5: ABO Blood Group Genotypes 93 Table 6: Values of ABO Blood Group Data of the Yoruba 98 Table 7: ABO Blood Group Data of Some Neighbouring Language Sub-Families 99 Table 8: ABO Grouping Patterns 105 Table 9: ABO Grouping (Interpretations) 108 Table 10: Yoruba Sub-Groups: Blood Groups, Percentiles and Gene Frequencies 109 Table 11: Values of X2 for Significance of Difference in ABO Blood Group Distribution in the Yoruba Sub-Groups 111 UNIVERSITY OF IBADAN LIBRARY xviii • 1 LIST OF APPENDICES Appendix 1: Sampling Locations of the Yoruba Sub-Groups -206 Appendix 2: Calculation of ABO Blood Group Percentiles 208 Appendix 3: Calculation of ABO Blood Group Gene Frequencies 209 Appendix 4: Calculation of X2 Values for the Yoruba Sub-Groups 210 Appendix 5: Yoruba Sub-Groups: Blood Group Distribution 213 Appendix 6: Yoruba Sub-Groups: Blood Group Percentiles 214 Appendix 7: Yoruba Sub-Groups: Blood Group Gene 215 Frequencies Appendix 8: Anova for Blood Group 'A' Percentiles 216 Appendix 9: Anova for Blood Group 'B' Percentiles 217 Appendix 10: Anova for Blood Group 'AB' Percentiles 218 Appendix 11: Anova for Blood Group 'O' Percentiles 219 Appendix 12: Anova for Blood Group 'A' Gene Frequencies 220 Appendix 13: Anova for Blood Group 'B ' Gene Frequencies 221 Appendix 14: Anova for Blood Group 'AB' Gene Frequencies 222 Appendix 15: Anova for Blood Group 'O' Gene Frequencies 223 UNIVERSITY OF IBADAN LIBRARY CHAPTER ONE INTRODUCTION General Background The ABO blood group distribution amongst the sub-groups of the Yoruba language sub-family of Nigeria is not known in detail. This applies as well, to many other populations in Nigeria in particular, and Africa in general. The study of such ABO blood group distribution amongst the sub-groups of the Yoruba language sub-family is useful for the reconstruction of their historical relationships, settlement history and anthropological affiliations or stratifications, as not hitherto known. Efforts at such historical and anthropological reconstruction in the past have been largely anchored on data from linguistics, oral traditions, some written history based on early colonialists' visits, some archaeological works, ethnography, palynology and other anthropology related studies. However, significant discoveries through such interdisciplinary research could not be corroborated by other valuable scientific studies, especially on the history of the Yoruba language sub-family in Nigeria (Fig. 1) . The Importance of ABO Blood Group Study The study of the ABO blood group distribution among the Yoruba 1 UNIVERSITY OF IBADAN LIBRARY 2 Fig. 1: Nigeria: (Ethnic Groups) Showing Yorubaland Fig 1. Nigeria : (Ethnic groups) Showing Yorubaland . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ UNIVERSITY OF IBADAN LIBRARY 3 is important since it is useful as an historical factor and as corroborative evidence for the varied accounts from linguistics, archaeology, oral tradition, palynology and other anthropology- related studies. ABO blood group study is useful in the sharper delineation of the settlement history of peoples (Fleure and James, 1916). It is possible through this source to assess and perhaps ascertain the make-up of the real people under study, through their blood samples, unlike archaeological data which are posited largely on the people's material culture. It makes possible the corroboration of hitherto known historical accounts of relationships between populations. It is useful for the provision of data that can be valuable in the management of blood transfusion centres within sample population. It is also useful: (i) for relating marked variations in gene frequencies of blood groups to existing linguistic, geographical and other boundaries between populations; (ii) for the resolution of paternity conflicts on individuals; (iii) for resolving the issues of the migratory movements of some populations; (iv) in explaining the influence of recent settler groups on UNIVERSITY OF IBADAN LIBRARY I 4 Fig. 2 : Yorubaland showing sub-groups f UNIVERSITY OF IBADAN LIBRARY 5 older (authochthonous) population; and (v) for highlighting groups that are anthropological appendages of others (Watkin, 1963). It is useful for deriving anthropological stratifications between groups that have lived together for some time (Lister et al. 1966). Since ABO blood group sampling is easy to undertake and exhibits polymorphism in populations (Worllegde, et al. 1974) Such studies will show differences existing between populations or within one group. The study of the ABO blood group especially in Nigeria and generally in Africa is in its infancy, particularly for such t language sub-families as the Yoruba, Igbo and Hausa who are known to have lived in their territories for a very long time. The ABO blood group study is of universal validity in the reconstruction of historical relationships. Language as Discriminant. It is possible to trace common descent between or within some groups or people by using language as a major discriminant. There are, at times variations of dialects, even within groups, some times from village to village, often reflecting heterogeneity within a recognised dialect group. The relationship(s) between UNIVERSITY OF IBADAN LIBRARY 6 language and common descent must, always be well studied. Oduyoye (1972:25) classified the Yoruba into two: the "i" and the "u" dialect units. He said that: The /i—/ and /u-/ dialect distintion coincides with a shibolleth /siboleth dialect distinction: wherever the speakers of the /i-/ dialect say the sibilant sh, the speakers of the /u-/ dialects say the sibilant s, and vice-versa. The common dialect has drawn its features from both groups: it has the /i—/ and not the /u-/. But it chooses its sibilant and shibilant forms according to the practice of the /u-/ dialect group. Examples are: Ovo/Ibadan Ondo-Ekiti/Iiebu-Iiesa "Yam" Isu Usu "Work" Ise Use Adetugbo (1973) identified three main Yoruba dialect units. Two of these, which he believed exhibit the characteristics of greatest antiquity and hence of older settlement status constitute the central group which includes: Ife, Ilesa, and Ekiti areas; and the south-eastern group (including Ondo, Owo, Ikale, Ilaje, and Ijebu areas). He believed all these were within the forest zone by the twelfth century. The third group of dialects in Adetugbo's (1973) classification, includes: Oyo, Osun, Ibadan and the northern Egba area; this north-western group historically associated with the Oyo UNIVERSITY OF IBADAN LIBRARY 7 o- CUlNAc--t-GS-t1 - n-GMAe-R o-Ftu«e.» c) J E&U1! Fig. 3. Biochemical Formulae of Antigens UNIVERSITY OF IBADAN LIBRARY 8 empire, he believed shows fewer traces of antiquity than the other two. ABO Blood Groups: anthropological works When Karl Landsteiner (1901) discovered the A, B and O blood groups; and Decastello and Sturli (1902) the fourth, AB (Bell et al, 1971) the major interest remained simply that of transfusion therapeutics. Hardly was any anthropological value ascribed to the ABO blood group distribution in human populations until the work of Hirschfield and Hirschfield (1919) in their pioneer studies of how the gene frequency distribution varied among the group of different nationalities serving on the Macedonian battle front. This thus awakened interest in the anthropological aspects of the ABO blood group distribution. Fleure and James (1919) in their study of the distribution of anthropological types in Wales, showed that there were physical anthropological differences within the population that settled in Wales; thus, opening the way for the resumption of further studies on the variation between English settlers and the Welsh in Wales. Fisher and Taylor (1940) in their blood group studies in Scotland, concluded that the blood group gene frequencies in some parts reflected some Scandinavian influence on the Scottish population. They noted a general trend of some south to north rise UNIVERSITY OF IBADAN LIBRARY 9 (a) -fbcad chalrw- -* ■ vwtaMe region long chairs ______ i antigen* / / short chain bridge (b) ru m T-TLTU r u u i T-TLTU Fig. 4: Antigen-antibody reactions. Source: P.T. Marshall (1978, Fig. 84, p.̂ 196) . UNIVERSITY OF IBADAN LIBRARY 10 in 'O' blood groups frequencies in England, while Scotland has a higher 'O' blood group frequency. Watkin (1952), showed the marked variations in the ABO frequencies in rural Wales in relation to such geographical features as the moorlands and coastal plains. The inhabitants of the moorlands vary widely in their 'O' and 'A' gene frequencies while their 'B' gene is consistently high. Chalmers et al (1953) obtained a low 'B' gene frequency value for the south-western Nigerians they sampled apparently because it was based on Yoruba/Bini sample admixtures. Blumberg et al (1961) found high 'B' gene frequency for the Yoruba to be 0.2815 Garlick (1962) prepared blood group maps for Africa with some advice that they be treated with reserve, especially as he could not take care of considerable local fluctuations, which size was small and the error correspondingly large. He obtained 'O' blood group percentiles for the Yoruba to be 70-75%. Hardy (1962) in her survey of ABO blood groups of southern Nigerians, showed that the ABO blood group gene frequencies of the Yoruba significantly different from those of the Bini, Ibo, Itsekiri, Urhobo and others, with a higher value of group 'B' which diminished eastwards through the Bini to the Ibo. Based on known historical accounts, she stated that the Yoruba UNIVERSITY OF IBADAN LIBRARY 11 possibly arrived at the present territory about 2000 years before present (Y.B.P.). She recorded the instance of some rise in the blood group 'B' frequency values from the Ibo to the Ibibio/Efik. She obtained the '0' blood group frequency for the Yoruba to be 0.6925 (Fisher's method); 0.7011 (Bernstein's method). Watkin (1963) established that Western Shropshire was an anthropological appendage of Wales, from similar, derived blood group frequency data. This is so, especially as the Welsh language has been spoken by native inhabitants since the begining of the eighteenth century. Dawson (1964) in elucidating the history of settlement in Ireland, found that the highest blood group 'B' values (frequencies) occur in the boglands of central plain thus reflecting the definite influence of the settlers of the moorlands and moorland fringes with whom raised blood group 'B' frequency is associated. Brown (1965) established an association between her sample of high gene 'B' in the people of the north east of Caithness and down the east coast of Moray Firth, and megalithic tombs thus implying some relationship between the present day population and older (autochthonous) population, whose advent he suggested dated back to neolithic times. UNIVERSITY OF IBADAN LIBRARY 12 Watkin (1965) found that 'O' blood group genic frequency in Shropshire is significantly higher than those of people of South- Western Chesire, thus suggesting an admixture with people with medium 'A' gene frequency of the latter population. Watkin (1966) went further to show that the raised 'B' gene frequencies of the English element in South Western Chesire and of the Welsh element in Eastern Shropshire point to the survival of elements of the autochthonous groups within these present day populations. Lister et a_l (1966) in their work on the Bedouin of Socotra concluded that the blood group frequencies implied that the Badouin were basically a Mediterranean (or Mediterranoid) population related to the continental Arabs with little influence from the African side. Roberts et a_l (1972) in their analysis of the ABO blood gene frequencies of the Sinhalese, concluded that there seems to be little genetic evidence for the affinities which tradition and cultural similarities suggest exist between the former (Sinhalese) and the Tamil. Worlledge et al (1974) in their analysis of the ABO blood group data of major Nigerian language sub-families showed how blood grouping could be easily carried out in large numbers of people with gene frequencies calculated. Such blood grouping they said, UNIVERSITY OF IBADAN LIBRARY 13 could be useful in population genetics since the techniques for achieving their analysis is very simple, and the blood group genes under consideration exhibit polymorphism. They concluded that a knowledge of the distribution of blood group antigens and their corresponding antibodies in any given geographical area is essential for the management of blood transfusion centres. They obtained the Yoruba 'O' blood group frequency to be 0.717. Udeozo (1985) noted that issues of the migratory movements of the Nigerian people can be resolved by identifying and studying the gene frequencies of the genetic markers in human blood in Nigerians, notably the Yoruba, Igbo and Hausa. He concluded that this is possible now as the history departments of Nigerian higher institutions add anthropology and archaeology to their specialities, in an attempt to improve on the historical accounts of our people. Aims of the Study; This work was conceived with the aim of achieving the following: a) A correlation between the information on historical accounts of the derivation of the Yoruba language sub-family, its sub-groups and the analysis of their ABO blood group samples. b) The analysis of the blood group genic frequencies UNIVERSITY OF IBADAN LIBRARY 14 Fig. 5: Kogi State Showing Yoruba Sub-Groups UNIVERSITY OF IBADAN LIBRARY 15 (biological evidence) for elucidating the issues of the derivation of the Yoruba language sub-family, its sub-groups and their settlement history. c) The derivation of the degree of survival of the older groups amongst the Yoruba language sub-family. d) The derivation of the extent of anthropological stratification or affiliation between the Yoruba sub-groups, along the two main dialect areas as postulated by Oduyoye (1972). e) The derivation of the extent of migrant influences on all or some of the Yoruba sub-groups. f) The derivation of any cultural influences that have had considerable effects on any of the Yoruba sub-groups since earlier \ settler times. g) The derivation of the effects of hybridization (biological and cultural) on the dialectical variants of some Yoruba sub-groups. h) The derivation of Yoruba sub-groups that are anthropological appendages of some other(s). i) The derivation of possibilities of prevalence of some blood group related ailments within the Yoruba language sub-family. j) The derivation of some biological evidence(s) based on the ABO blood group study for corroborating the many propositions UNIVERSITY OF IBADAN LIBRARY 16 Fig. 6: Kwara State Showing Yoruba Sub-Groups UNIVERSITY OF IBADAN LIBRARY 17 of some anthropology related studies, particularly linguistics, archaeology, palynology, ethonography and oral traditions. k) The derivation of any variations within the Yoruba language sub-family against a background of geographical features of some of the sub-groups's territories. Scope of Study This work is the result of field and laboratory sampling of the blood of 75,000 individuals of these 25 Yoruba sub-groups: Akoko, Akure, Awori, Bunu, Egba, Egbado, Ekiti, Eko, Ibarapa, Ibolo, Ife, Igbomina, Ijebu, Ijesa, Ijumu, Ikale, Ilaje, Ilorin, Kabba, Ondo, Owo, Owu, Oyo, Remo and Yagba. The work was carried out between April, 1988 and October, 1990; then between February and July, 1991. The samples were obtained from donors in the major settlements of each sub-group and those of donors and patients in some of the hospitals (particularly the blood banks) in the sub-groups' territories (Fig 2.; Table 1). The blood samples of 3,000 individuals were considered for each sub-group (made up of 600 from field donors and 2,400 from blood bank samples) taken as six equal batches of 500 each to obtain replicates which assured adequate representation required for bio-statistical analysis (table 10; appendices 5 - 6) . The co- UNIVERSITY OF IBADAN LIBRARY 18 Fig. 7: Lagos State Showing Yoruba Sub-Groups ~T— ~l--- 2° A 5' 3° 3°157 3°30' 3° AS' 2,° 4° 15' ^ AWORI 0 L. 20_L_ 40 KmJE B U _i M EK0 OGUN S T A T E / i6° AS Fig. 7 : Lagos state showing Yoruba sub-groups UNIVERSITY OF IBADAN LIBRARY 19 operation and assistance of blood banks (or blood transfusion centres) of hospitals in the major towns of the different sub­ groups were relied on for convenience of analysis and of obtaining the blood samples of attending donors/patients. The sub-groups of the Yoruba language sub-family sampled in this study were identified based on similar anthropological factors such as language, history, territory, cultural and economic relationships as proposed by Lewis (1978) who reflects a historical approach to the study of peoples, thus suggesting that the sub­ groups of the Yoruba considered are ethnic groups. However, Barth (1969) in delimiting 'ethnic' boundaries is rather more pragmatic in his own approach. He explains that boundaries which are maintained by a limited set of cultural values are useful for identifying 'ethnic' groups. The persistence of such units over time, he found, depend on the persistence of some cultural differentiae. Language has been shown within the larger language relationships to be a major discriminant in identifying 'ethnic' groups. Since there could be limitations in using language as discriminant especially as a factor of common descent, biological correlation becomes inevitably necessary. The scope of this study UNIVERSITY OF IBADAN LIBRARY 20 TABLE I; YORUBA SUB-GROUPS: LOCATIONS AND MAJOR TOWNS (To read with Fig. 2) Yoruba Sub-Groups Territories/Local Government Areas and States Major Towns 1. Akoko Akoko Local Government Area, Ondo State lkare 2. Akure Akure Local Government Area, Ondo State Akure 3. Awori Ado-Odo/Ota Local Government Area, Ogun State; Lagos State Ota 4. Bunu Oyi Local Government Area, Kogi State Akutupa 5. Egba Egba Division, Ogun State Abeokuta 6. Egbado Egbado Division, Ogun State Haro 7. Ekiti Ekiti Division, Ondo State and Ekiti Local Government Area, Kwara State Ado-Eki ti 8. Eko Lagos Island, Ikeja, Isolo, Apapa, Ebute Metta, Mushin, Yaba, and Ketu Areas of Lagos Lagos 9. Ibarapa Ibarapa and Ifeloju Local Government Areas, Oyo State Eruwa 10. Ibolo Offa and Oyun Local Government Areas, Kwara State Offa 11. Ife Oranmiyan Local Government Area, Osun State Ile-Ife 12. Igbomina Ifelodun and Irepodun Local Government Areas, Kwara State Omu-Aran 13. Ijebu Ijebu Division, Ogun State; Epe, Ibeju-Lekki and Ikorodu Local Government Areas, Lagos State Ijebu-Ode 14. Ijesa Ijesa Division, Osun State Ilesa 15. Ijumu Oyi Local Government Area, Kogi State Ayetoro 16. Ikale Okitipupa Local Government Area, Ondo State Okitipupa 17. Ilaje Ilaje Division, Ondo State Igbokoda 18. Ilorin Ilorin, Asa and Moro Local Government Areas, Kwara State Ilorin 19. Kabba Oyi Local Government Area, Kogi State Kabba 20. Ondo Ondo Local Government Area, Ondo State Ondo 21. Owo Owo Local Government Area, Ondo State Owo 22. Owu Irewole Local Government Area, Osun State Orile-Owu 23. Oyo Oyo, Osun and Kwara States Oyo 24. Remo Remo Division, Ogun State; Part of Ikorodu Local Govt, Area, Lagos State Sagamu 25. Yagba Yagba Local Government Area, Kogi State Isanlu UNIVERSITY OF IBADAN LIBRARY 21 Fig. 8: Ogun State Showing Yoruba Sub-Groups 2%0' TU5' TOC/ 3° 30' 3°*. 5' A0 0 0' 4° 15 '--------- 1--- ,-------------- - i IJEBU 0 Y 0 STATE REMO AWORI EGBA • EGBADO T 30 OS U N 7°15 / S T A T E 30 60Km. 7° 00 ' ]---- j 6PA5' 6°30 B i g h t o f B e n i n 6° 20' J--------l I Fig. 8 : Ogun shahe showing Yoruba sub-groups REP. UNIVERSITY OF IBADAN LIBRARY 22 thus, includes an insight into the historical relationship of the Yoruba sub-groups as perceived today compared to the results of their respective ABO grouping data. The possibilities for the derivation of genetical data (after Cavalli-Sforza's, 1966 style) particularly the genealogy of the Yoruba, from this work is advisable for future work since this is beyond the purview of the present study. The scope of this study, therefore, entails the following: i) Identification of the 25 Yoruba sub-groups and their respective individuals within the area designated by anthropologists and historians as Yorubaland (Fig. 1). ii) The analysis of the ABO blood group samples of 3,000 individual donors from each Yoruba sub-group. iii) The derivation of the distribution, percentiles and gene frequencies of the four ABO blood groups for the 3,000 samples obtained for each sub-group. iv) The historical background of the Yoruba in general and each sub-group in particular, with literature review of the ABO blood group. v) Results (with biostatistical analysis) and discussion. vi) Summary and Conclusion. UNIVERSITY OF IBADAN LIBRARY UNIVERSITY OF IBADAN LIBRARY 24 The Study Area: Territory and Sub-groups' Locations The study area of this work is the traditional Yorubaland of Nigeria lying roughly between latitude 6° and 9° North and longitude 2° 30' and 6° 30' East. Johnson, (1921) estimated it to be about 181,300 square kilometres (Atanda, 1980) lying within the Guinea forestlands and the savannah. (Smith, 1988; Fig. 1.) Today, the Yoruba territory in Nigeria includes the whole of Lagos, Ogun, Ondo, Oyo and Osun and parts of Kwara and Kogi states with its peoples numbering about 20 million (projected 1963 figures) (Figs. 5 -11). There are instances of some Yoruba in Edo State, neighbouring Republic of Benin and South America. Each of the Yoruba sub-groups was sampled through individual donors at the blood banks of hospitals in their major towns after necessary preliminary interviews. The twenty-five Yoruba sub-groups considered in this study were sampled for over three years, and were so far those within Nigeria. Four other groups: Idasa, Sabe, Popo and Ketu exist in the Republic of Benin (Fig. 2) while the Ikiri, Oworo, Gbede. Ogidi and Ayere exist as sub-units of the Ijumu. The twenty five Yoruba sub-groups studied show cultural features (Barth, 1969) which include: common UNIVERSITY OF IBADAN LIBRARY 25 language (or dialect), common territory, common descent, common economic, cultural and administrative ties (Lewis, 1978). These twenty five Yoruba sub-groups are shown with their major towns (Figs. 5-11) and locations within the entire territory (Table 1; Fig. 2) . UNIVERSITY OF IBADAN LIBRARY 26 Fig. 10: Osun State Showing Yoruba Sub-Groups UNIVERSITY OF IBADAN LIBRARY CHAPTER TWO LITERATURE REVIEW Earlier Work on the Yoruba and Yorubaland: Prior to this work, much work that has been relevant to the study of Yoruba people and their history had been carried on through Linguistics, Archaoelogy, Palynology, Ethnography, History and Biology. Such work is not restricted , however, to the Nigerian area taken as Yorubaland by historians and anthropologists; but extends to areas flanking .Daland and whose people share relationships with the Yoruba. Such work is pertinent for the biological reconstruction and will help in buttressing the evidence from Linguistics, Archaeology, Palynology, Ethnography, and History. There is need to highlight salient aspects of such historical accounts and settlement background information. Linguistics; Greenberg (1963; 1964) classified African languages into four major divisions (Fig. 13; Table 2) based mainly on some linguistic analysis of the African people. The four major divisions according to him are: Congc-Kordofanian, Nilo-Saharan, Afro-Asiatic and Khoisan. The f rst (Congo-Kordofanian) comprising Niger-Congo sub-division consists of the West Atlantic, Mande, Voltaic, Kwa, Benue-Congo and 27 UNIVERSITY OF IBADAN LIBRARY 28 Adamawa-Eastern families. This sub-division covers West Africa and parts of Central Africa. Gregerson (1977), conscious of some similarities between the Nilo-Saharan and the Congo-Kordofanian language divisions as classified by Greenberg (1963), has suggested their merger under the name Kongo-Saharan. Andah (1987) has also observed that the two linguistic divisions, Nilo-Saharan and Congo Kordofanian may have been related. Andah (1987) suggested that the proto-forms of the languages within the Niger-Congo sub-division have been spoken for a very long time by people of Negroid stock living in various parts of West Africa. Lexicostatistics and glotto-chronology, he said, take these back to at least, terminal Pleistocene times. He noted that the Chadic (Hausa, Kanuri, Bauchi) languages spoken today are in contrast, relatively recent arrivals there. Among the Kwa-speaking people of the Niger-Congo language sub­ division are the Akan, Yoruba, Edo, Igbo, Nupe, Igala and Bassa. Armstrong (1964) maintains that it is not yet possible to translate the relationships between languages such as Fula and other Kwa languages including Twi, Yoruba, Igbo, and then the Bantu, into a chronological scheme. He suggested a separation time of about 2000 years between the UNIVERSITY OF IBADAN LIBRARY UNIVERSITY OF IBADAN LIBRARY - 30 - Ri,g.12: Yorubaland showing two major dialect areas ^ A f t r r O r l t i y o y r ) t . ■ UNIVERSITY OF IBADAN LIBRARY 31 Oyo Yoruba and the Igala on the basis of a comparison of their basic vocabulary (Andah, 1987). Andah (1987) has observed that it is not realy possible to study Yoruba cultural history meaningfully without reference to those of related neighbours like the Nupe, Bariba, Ebira and Igala. He noted that the lower Niger region, further south, was the seat for the development of several civilizations by Kwa speaking people as were the kingdoms and empires of the Yoruba, Aja and Edo speaking people which dates back to at least, 11th and 13th century respectively. The Yoruba constitute a major language sub-family with their homeland in the south-western part of Nigeria, occupying the whole \ of Lagos, Ogun Ondo, Oyo, Osun and parts of Kwara and Kogi states, (Fig. 2). Some Yoruba presence is known in the Republic of Benin; mainly as the Idassa, Ketu, Popo and Sabe. They are also found in some parts of Edo State. A good number of the Yoruba are found in the West Indies and South America (Atanda, 1980) owning largely to their dispersal during the slave trade. Through the use of glottochronology, linguists have been able to assert that Yoruba, Edo and Igbo began to evolve as separate languages from about four thousand years ago; while Yoruba, had evolved as a distinct language, at least about two or three thousand years ago. It UNIVER ITY OF IBADAN LIBRARY CLASSIFICATION OF AFRICAN LANGUAGES (After Greenberg, 1963) Congo-Kordofanian I A Niger-Congo I A 1 West-Atlantic I A 2 Mande I A 3 Voltanic 1A A Kwa I A 5 Benue-Congo I A 6 Adamawa-Eas tern I B Kordofanian Nilo-Saharan II A Songhai II B Saharan II C Mahan II D Fur II E Chari-Nile II E 1 Eastern Sudanic II E 2 Central Sudanic n E 3 Berta ii E A Kunama II F Roman Afroasiatic III A Semitic III B Egyptian III C Berber III D Cushitic h i D 1 Northern Cushitic h i D 2 Central Cushitic h i D 3 Eastern Cushitic h i D A Western Cushitic h i D 5 Southern Cushitic III E Chad Khoisan IV A South African IV A 1 Nor them IV A 2 Central IV A 3 Southern IV B Sandawe IV C Hadza UNIVERSITY OF IBADAN LIBRARY 33 Fig. 1 3 : Linguistic map of Africa (After Greenberg) UNIVERSITY OF IBADAN LIBRARY 34 follows that Yoruba speaking people had been in West Africa before the advent of Oduduwa (Atanda, 1980) As Horton (1970:71) precisely puts it: A f f i n i t i e s o f t h e Y o r u b a l a n g u a g e a r e o v e r w h e l m i n g w i t h t h e l a n g u a g e s o f t h e n e i g h b o u r i n g West A f r i c a n p e o p l e r a t h e r t h a t w i t h t h e l a n g u a g e s o f a n y o f t h e p e o p l e o f t h e M i d d l e E a s t . Smith (1988) suggests also that the settlements of North-West Yoruba, are more recent than those of the North-East Yoruba whose dialects he believes represents an earlier stage of the Proto- Yoruba. He (Smith, 1988:16) summarised thus: The l a n g u a g e s most s i m i l a r t o Y o r u b a and p r e s u m a b l y st em m ing fro m P r o t o - Y o r u b a a r e c o n c e n t r a t e d i n N o r t h - E a s t Y o r u b a l a n d and i t s a d j a c e n t a r e a s . . . m i g r a t i o n s r e c o r d e d i n Y o r u b a t r a d i t i o n s t o o k p l a c e o v e r o n l y r e l a t i v e l y s h o r t d i s t a n c e s w i t h i n t h a t p a r t o f West A f r i c a l y i n g West o f t h e N i g e r - B e n u e c o n f l u e n c e , I f e was a d i s p e r s a l c e n t r e f o r an i m p o r t a n t s e c t i o n o f t h e m i g r a n t s . . . t h e i n f l u e n c e o f I f e on t h e o t h e r d i a l e c t s o f Y o r u b a seems t o h a v e b een s m a l l . Whereas, Tamuno (1965) listed the Yoruba as one of the peoples of the Niger-Benue confluence civilization, Ryder (1984) infers from the dialect analysis of the Yoruba language sub-family that they expanded from the forest into the savanna. In his view, there would seem to be some contradiction between linguistic analysis and UNIVERSITY OF IBADAN LIBRARY 35 historical tradition; contradictions attributed by some to be due to movement of secondary population from the forest to the savanna and vice versa. Oduyoye (1972) had partitioned the Yoruba language sub-family into two dialect groups: the "i" and "u" based on a shiboleth/siboleth dialect distinction. He thus, divided Yorubaland into two dialects areas (Fig.12). Adetugbo (1973) identified three main Yoruba dialect groups. Two of these which he believed were of greater antiquity, and hence of older settlement; are the central group (comprising Ife, Ilesha and Ekiti areas) and the South- Eastern group (the Ondo, Owo, Ikale and Ilaje and Ijebu areas.) According to him, all the areas of these listed Yoruba sub­ groups fell entirely within the forest zone in the twelfth century. The third group of dialects embraces Oyo, Osun, Ibadan, and the northern Egba area: which he said, were historically associated with the Oyo empire and shows fewer traces of antiquity than the other two (Table 1; Fig.2). Archaeology: Research in Archaeology over the years has provided evidence regarding the early history of populations of early Yorubaland and areas westwards and eastwards and eastwards of it (Table 3). To the West of Yorubaland in the Akan culture area, we have UNIVERSITY OF IBADAN LIBRARY 36 information ranging from identified industrial complex at Kintampo dated to 915 + 290 BC. (Davies, 1964) to late Stone Age levels at Bosumpra predating 3420 B.C. (Smith, 1975). In the Edo and Igbo speaking areas, eastwards of Yorubaland, it would seem that the early city of Benin was in existence by 1305 + 105 A.D. (Connah, 1972) while at Igbo-Ukwu, there was already in existence, a sophisticated Bronze-casting tradition in the 10th century (900 A.D.), Thurstan Shaw (1967). A late Stone Age complex dated between 5000-3000 Y.B.P. was reported for Afikpo by Andah and Anozie (1980): while at Ugwelle-Uturu, earlier Stone Age materials have been identified as pre-dating 11,000 Y.B.P., although precise dates are yet to be obtained (Anozie et aJL. , 1978) . Within Yorubaland, skeletal remains have been dated to 11, 000 Y.B.P. at Iwo-Eleru (Thursan Shaw and Daniels, 1984). At Mejiro cave, some late Stone Age artefact are dated to 5000 Y.B.P. (Willet, 1960), while excavations at the ancient settlement of Old Oyo indicate the existence of a town settlement at around 810 +80 A.D. (Agbaje Williams, 1981) and levels containing potsherds have been dated to 1,100 + 110 A.D. (Diogun pottery); 1300 + 80 A.D (Mejiro Pottery) (Soper and Darling, 1980). Charcoal dates of +560 and 980 A.D. were obtained from a pre-town occupation for Ile-Ife, while dates of two potsherd floors at Ita Yemoo have been dated to 960 A.D. and UNIVERSITY OF IBADAN LIBRARY X A d LiE j SUMMARY OF ARCHAEOLOGICAL DATES OF SITES RELATED TO YORUBALAND Archaeological Site(s)’ or Sample(s) Dates Author(s) Date (s) 1. Kintampo Davies (1964) 915 + 290 B.C. 2. Bosumpra Smith (1975) Before 3420 B.C. 3. Benin Connah (1972) 1305 + 105 A.D. 4. Igbo-Ukwu Shaw (1967) 900 A.D. 5. Afikpo Andah & Anozie (1980) 5000 - 3000 Y.B.P. 6. Ugwuele-Uturu Anozie et al (1978) Before 11,000 Y.B.P. 7. Iwo-Eleru Shaw & Daniels (1984) 11,000 Y.B.P. 8. Mejiro Cave Willet (1960) 5000 Y.B.P. 9. Old Oyo Agbaje-Williams (1981) 810 + 80 A.D. 10. Diogun Pottery (Old Oyo) Soper & Darling (1980) 1100 + 110 A.D. 11. Mejiro Pottery (Old Oyo) Soper & Darling (1980) 1300 + 80 A.D. 12. Ile-Ife (Charcoal) A.F.C. Ryder (1984) + 560; + 980 A.D. 13. Ile-Ife (Ita Yemoo) A.F.C. Ryder (1984) 960; 1060 A.D. 14. Iffe-Ijumu (Kernel) Oyelaran (1991) 2210 + 80 A.D. 15. Niger Delta Cores Sowunmi (1981) 2800 Y.B.P. UNIVERSITY OF IBADAN LIBRARY 38 1060 A .D . (Ryder, 1984). In North-East Yorubaland, an area referred to by Atanda (1980) and Smith (1988) as the home of the 'Proto Yoruba' Oyelaran (1991) obtained radio-carbon dates of 2210 + 80 Y.B.P. for palm kernel fragments from Itaakpa. (Table 3) Not much can be made of this until the associated pottery is studied in detail and we are in a position to ascertain what, if any affinities these have with known Yoruba traditions. Pollen analysis of some Niger-Delta cores (Sowunmi, 1981) suggest that by 2800 Y.B.P. there was deforestation in Southern Nigeria probably as a result of farming activities. The rapid and significant increase in Elaeis guineensis (oil palm) pollen appears to corroborate this. (Table 3) History Most early historical accounts of the Yoruba concerning pre- Ife origins tend to be distinguished by the fact that they claim the North Eastern parts of Africa as the original home of the Yoruba. These parts include Egypt, Arabia, Nubia, Axum, Tigre, Punt, Sudan and the Quadai (or Waddai) (Fig. 19). The tendency to derive the Yoruba people from the East has usually been based on supposed cultural similarities between the Yoruba and the people of Egypt. Examples of such are the works of UNIVERSITY OF IBADAN LIBRARY 39 •>9 Johnson (1921) and Lucas (1948). This notion of Egyptian derivation has remarkable similarities with the historical accounts of some other West African groups (Aderibigbe, 1965). It is generally suggested that Arab-inspired military campaigns, thought to have assumed serious proportions between A.D. 632-1099, at the death of prophet Mohammed (Gibney, 1978; Hirsch 1993) was the cause of southerly migrations that could have given rise to movements into areas south of the Sahara. However, trade routes into Africa were said to have emerged between 1500-1200 B.C. once the Arab domesticated the dromedary camel (Gibney, 1978). Smith (1988) believes that the Arab conquest of North Africa in the seventh century might have resulted in movements which eventually completed the assimilation of some people by the Yoruba in their present homeland. According to Aderibigbe (1965): "there is no longer the old tendency to accept the idea of Yoruba migration from Egypt without question." It is now generally agreed that, in actual fact, there have been no systematic attempts to derive genuine migrations for the Yoruba or other language sub-families. The idea of migration from the East is to be thus, approached cautiously. The basic concepts of rules for studying migratory movements based on UNIVERSITY OF IBADAN LIBRARY 40 archaeological evidence have never been employed. There is there fore no basis of cultural facts to support the claims of such migrations. Islamic and Biblical affiliations are being used to fabricate history; a manner of "mythologizing history". It is reasonable from the mythological historical accounts associating the Yoruba with peoples of the middle east of Africa to conclude that these are mere speculations! Ile-Ife represents the earliest identified stage in the development of Yoruba culture, which most probably took place towards the end of the first millennium, 1000 A. D . Ife is usually thought to be the first settlement of the Yoruba while other towns were formed by the different sub-groups that migrated northwards or southwards, absorbing or driving away the original settlers (Lucas, 1948). It was from this base that the Yoruba extended their sway over the aboriginal inhabitants called the Ugbo (Atanda,1980) about whom little is known, creating other settlements as they advanced southwards (Aderibigbe, 1965). From the stone, bronze and iron works as well as the remarkable terracottas retrieved from archaeological and historical contexts, it is clear that the Yoruba attained a high level of culture at Ife. Ife was said to have been listed by Herodotus (484 - 424 B.C.) UNIVERSITY OF IBADAN LIBRARY 41 UNIVERSITY OF IBADAN LIBRARY 42 as one of the five cities that had existed between 3000 to 1000 B.C. (Fabunmi, 1985). The next set of immigrants to reach Ile-Ife was led by Oduduwa. Oduduwa met Agbomiregun at Ile-Ife (Atanda, 1980). Thus, Oduduwa did not belong to the earliest known generation in Yoruba history. According to oral traditions, the first group of the Yoruba to reach Ile-Ife came under Iwase, during the reign of the Esumare of Ife, Oba Erinrin (I.D.A., 1991) Horton (1979:74) summarisses the historical role of Ife thus: I f e was t h e f i r s t g r e a t Y o r u b a K in g d o m and t h e s o u r c e o f t h e r o y a l d y n a s t i e s o f t h e o t h e r m a j o r s t a t e s o f t h e r e g i o n . Yoruba History: i Since Yoruba history had been based essentially on Ife as a source of derivation, there is the need to relate Ife with the history of each sub-group considered in this study in order to afford a genuine basis for the comparison of the biological evidence with the historical and cultural. The history of the Yoruba sub-groups as highlighted in this study will be of great value in determining to what extent each reflects the Ife relationship. There is also the possibility of assessing the level of presence of the aboriginal (autochthonous) populations by studying the history of the Yoruba sub-groups. This is why it has UNIVERSITY OF IBADAN LIBRARY 43 Fig. 15: Yoruba Territory Between 1100 - 1500 (After Ryder) CD UNIVERSITY OF IBADAN LIBRA Y 44 become important to assess the historical accounts of the Yoruba sub-groups. The historical account of the Yoruba sub-groups is taken in an anti-clockwise manner, from North-West to South West, then to South East and North East of Yorubaland. History of the Yoruba Sub-Groups: The Yoruba language sub-family is made up of sub-groups whose history is often told from the viewpoint of the royal leadership instead of the settlement history of the entire sub-groups. Such sub-groups have become distinct as a result of some degree of isolation and access to resources of common interest. As Alexeev (1986:265) puts it: The i s o l a t i o n o f t h e s e p a r a t e g r o u p s and more p r o b a b l y o f a g g r e g a t e s o f t h em , s e e m i n g l y became g r e a t e r a f t e r t h e f o r m a t i o n o f l i n g u i s t i c d i f f e r e n c e s and r e m a i n e d a t one and t h e same l e v e l u n t i l t h e d e v e l o p m e n t o f many s o c i a l i n s t i t u t i o n s w i t h i n w h i c h l a n g u a g e b a r r i e r s were a l r e a d y overcom e i n a s y s t e m o f o t h e r , more d e v e l o p e d s o c i a l r e l a t i o n s . Each Yoruba sub-group has its own history which is distinct one hand and as well related to the accounts of the entire Yoruba historical tradition on the other hand. The influence of Ife on the sub-groups needs to be noted and fully clarified against the UNIVERSITY OF IBADAN LIBRARY 45 Fig. 16: Nigeria (Ancient States) in the 16th Century (After Lafene) UNIVERSITY OF IBADAN LIBRARY 46 background of cultural, linguistic, historical and biological evidence. This will enable the resolution of the questions that the multi-disciplinary assessments generate. Ovo: The Oyo sub-group is found in Oyo and Osun States (Fig. 10 and 11). The Oyo sub-group constitutes the largest sub­ group whose cultural appendages include such sub-groups as the Awori, Egba , Ibarapa, Ibolo, Ife, Igbomina, Ilorin and Owu and have been known to be in this territory at least by the 8th century (Agbaje-Williams,1981). Historical accounts available suggest that they are derived from at least three sources: i) as an outgrowth of older Yoruba sub-groups who came from the forested areas of Yorubaland (based on dialect analysis) (Ryder, 1984) ; ii) from the lineage of Karbogari's son through which, according to one tradition, the seven bastard Hausa states: the banza 'bakwai' emerged (Adamu,1984); iii) as descendants of the same lineage with the Borgana as related in the Kistra legend (Smith, 1988) The Oyo were known to have met an autochthonous population at Oko (under the leadership of Egboro, the Oloyokoro) in that territory at the time of settling down there (Smith, 1988). UNIVERSITY OF IBADAN LIBRARY 47 Fig. 17: Nigeria (Ancient States) by the 17th - 18th Century (After A ja y i and E s p i r e ) * 5° 110° L a n d o v e r 9 0 0 m 01 _ _i_5_0 _ 1i 00„ i150 Km. A p p r o x im a t e l i m i t o f th ic k f o r e s t — limits of — 150 — Principal States \ / // GOBIR • ) / _' _____ (' Sokoto ^ ^ ^ K/at-s-in-a1i .D~a ura BORNU N l cF aad a-mN -xrG..u.rrrm0^avNK'7ebbi. \ * i -- Hadejia ( • .Gw, anda V /"K an<\A OID.A M\\ Kukwa W GU• RMA’/ X / KEBBI [ZAMFARA ^ J l . W i f . \ BORGU A o * vZaria // Sansanne- /a?/ n— ✓ 'V Bauchi Mango Busa.V/ *Kontogora \ / \ Plateau 10° - \ N U P E N Old Oyo^ \ ✓ ' / \ Yola _______ / llo rin *V * n \ / j u / R U N Atakpam^3̂ * ! 0 Y 0 , / • Ibadan j |e / ' . Wuikari •Abomey. % / ' //////^>/ Idah - V ' — ----- - / B e n m V '/////,y *- o O T) CT t -n — < b e n i n ; i b o ^^ O.CT o . , ■>" *> Cameroon Mts. ? £ fti CD B i q h f " ( / 7 ^ 0 w e r n *A r ° .C h U k U ^ , of | Old Calabap^ 5*- Benin Brass Bonny Bignt of Biafra Fiq. 1ft: N ig e r ia (ancient- s ta te s ) hv 1 7 ^ - 1 r e n t u r v UNIVERSITY OF IBADAN LIBRARY 48 The Oyo, despite suggestions of far north or middle east influences would seem to have been derived from populations which grew around Old Oyo till the era of Oranmiyan's migration into Ife as a result of military superiority. The Oyo kingdom said to be the largest and the most powerful in Yorubaland (Atanda, 1980) is believed to have been founded by Oranyan who succeeded Oduduwa at Ife but later journeyed out on some military expendition. At the time of settling his followers at Oyo-Ile (or Old Oyo) near the Ajaka hill, Oranyan named the new town 'Oyo' implying: 'the slippery place', since his horse has slipped and stumbled on the hillside (Smith, 1988). At Oranyan's demise his sons Ajaka and Sango ruled consolidating his (Oranyan's) territorial gains as well as curtailing troublesome neighbours such as the Borgana, Nupe, Owu and Ijesa. (Atanda, 1980) Significant militarisation became a feature of the kingdom as from the time of Onigbogi (c.1580 -1542); Orompoto (c.1542-1580); Ajiboyede (c.1580 - 1590) during which the capital earlier taken to Igboho was reconstituted at Oyo. This military development continued into the reign of Ajagbo and Ojigi culminating in the appointment of "Are Ona kakanfo" or Generalissimo bringing the kingdom to its peak of power by mid-18th century. This afforded the extension of Oyo authority from Jebba to Badagry coast while its sway extended over UNIVERSITY OF IBADAN LIBRARY 49 J I X X J B E N I N s ’ , N ik k i*/ -—1̂: Ka•r >/ • hamaJ' s 1 — N I G E R I A1 Bida {l \! ] • • I gboho • ' il lfior n̂" \ \ \ #r f?(: • :.' WIJUUM ottun. N^\ w m'KeKw d ^'■'■ gebV^< IGBIRA)• f9Own/ r ■ * * X ~ " i arri VX' X The Ono Ki ngdom Kingdom of Benin in 1760 (showing expansions) Modern Igboland National^ Dahomey in 1780 Boundaries --------------Boundary of Voruba speaking peoples Fig i& j Yorubaland and nearby states before 1800 A.D. ADAPTED FROM WEST AFRICAN HISTORY A D 1000 TO THE PRESENT O-U-P. 1983 (AFTER ISICHEI) UNIVERSITY OF IBADAN LIBRARY 50 the Egba, Egbado, Abomey, Popo, Sabe. Ketu, Idassa and the Awori. Oyo decline came c.1796 through the conspiracy of Afonja and some Fulani Jihadists led by (Sheikh-Al-Salih or Alimi) whose army was eventually defeated in 1838 at Osogbo. The era occasioned Alafin's of short reigns: Aole (c.1789 -1796); Adebo & Maku (c.1796 - 1799); Majotu (or Mansola) ; 1802 -1831); Amodo (c.1831 - 1833); Oluewu (1833 - 1836) and Atiba. (Smith,1988). The Oyo were hunter-gatherers since their settlement days even though ample evidence exists of their exploitation of their open terrain for food and tree crops farming. (Mabogunje & Omer-Cooper, 1971). The Ilorin are found in Ilorin, Asa and Moro Local Government Areas of Kwara State. They date back to the 11th century by which time they were already noted for at least, the art of metal smithing hence, the ethnonym: "Ilorin" derived from "Ilu Ilo irin" or "town of metal smithery". They are believed to have been derived from the Oyo and Egba mainly and some instances of settlers from Nupe and Borgu territories. The Ilorin met the people of Oke-suna, Ogele, Kanla, Oke-male, Ganma, Elehinjare, Idofian, Oke-Oyi, Ibare, Igbon and Iresa there (Mabogunje and Omer-Cooper, 1971). The Ilorin territory of a conglomerate of smaller settlements with Afonja, Solagberu, Ojo Isekuse as some of the leaders was part UNIVERSITY OF IBADAN LIBRARY 51 UNIVERSITY OF IBADAN LIBRARY 52 of Oyo kingdom up till the time of the Afonja conspiracy, in 1796 (Smith, 1988). Whereas it was Afonja's aim to grab power with the help of the Fulani Jihadists he was later exterminated alongside Solagberu. The activities of the Fulani Jihadists between 1820-38 was considerable such that it caused the beginning of Oyo decline. Oyo culture survived in Ilorin even to the extent the Fulani Jihadists learnt to speak the Yoruba language which assisted them in their islamization and the establishment of an Emirate. (Atanda,1980). By 1821, Southern Yorubaland was already aflame with the war especially with the attack of the Owu by a joint military expedition of Ijebu, Ife and itinerant Oyo soldiers. (Mabogunje and Omer Cooper, 1971) The early mastery of metal smithery by the Ilorin was an advantage in the pursuit of a hunter-gatherer tradition which went alongside some farming in cash crops of economic importance thus affording their women some aptitude in the processing of cereals and other stem tuber products (Smith, 1988) . The Ilorin were hunter-gatherers since their early settlement days, especially with the variety of weapons that their metal- smithery afforded them. They carried out farming in some cash crops of economic value and this afforded their women some aptitude in post-harvest technologies (Smith, 1988). UNIVERSITY OF IBADAN LIBRARY 53 Ibolo: The Ibolo (or Igbolo) are found today in Offa and Oyun local Government Areas of Kwara State. The major settlements of the Ibolo include: Offa, Ippe or (Ipe), Erin-ile, Ilemona or (Illemona), Igosun, Ira or (Irra), Ijagbo and Igbana. They are believed to have been in this territory by the 10th century, at least when the earliest settlers said to have been of Oyo extraction came even though some more recent settlers claim Ife derivation. This seems to be confirmed by the fact that the Ibolo still celebrate a "Moremi" festival annually in remembrance of the Ife episode with the Ugbo (or Ubo) forest dwellers. The people of Offa and its immediate district are often called "Ibolo" (or Igbolo) meaning: "oil palm gatherers." Oluwole, the founding father of the Ibolo kingdom as well as nine of his successors were said to be of Oyo extraction, hence their loyalty to the Alafin. The capital at Offa was subject of Nupe and Ilorin imperialism which was resisted. They are oil-palm processors in addition to having a hunter-gatherer tradition and a subsistent farming custom of food and cash crop cultivation (Smith, 1988) Owu: The Owu are today found mainly in Irewole local Government UNIVERSITY OF IBADAN LIBRARY 54 Area of Osun State and elsewhere in Igbo-Owu (Kwara State), Abudu (Edo State), Owu-Ijebu and Owu-Egba (Ogun State), Ajebandele (Ogun/Ondo State boundary), Ago-Owu (Lagos State) and Owu-Orile near Oyo in Oyo State. The Owu in Osun State are indigenous to their territory while those in Kwara, Edo, Ogun, Ondo, Oyo and Lagos states are reported to have arrived there after the collapse of the Owu kingdom in 1821 (Mabogunje and Omer-Cooper, 1971) intermixing with Oyo, Ijebu, Ondo, Igbomina, Edo and the Egba. The Owu Kingdom is believed to be one of the earliest and oldest of Yoruba kingdoms (Mabogunje & Omer-Cooper, 1971; Atanda, 1980). The evidence that by the 15th century, Owu settlement in Osun State (Fig. 10) had become a military outpost of the Oyo empire is true. The ethnonym "Owu" is said to have been derived from "one who sobs" in reference to the manner in which its patriarchal Asunkungbde (meaning: "one who cries to earn a crown") is said to have obtained his crown from Oduduwa, his maternal grandfather, thus implying a relationship (Mabogunje & Omer-Cooper, 1971). Owu as a military outpost was effective in fulfilling Alafin's military behests especially against the Ife. The combined attack by the Ijebu, Ife and free Oyo soldiers in 1821 led to its fall causing some widespread dispersal of its people into other territories of the Yoruba. UNIVERSITY OF IBADAN LIBRARY 55 The Owu were effective hunter gatherers with a tradition of farming in economic crops while the produce were sold at the popular Apomu market under its control. (Mabogunje and Omer-Cooper, 1971). Ibarapa: The Ibarapa are found in Ibarapa and Ifeloju local government Areas of Oyo State where they probably have been by the 16th century at the peak of the Oyo Empire. The territory was originally made up of seven towns: Eruwa, Lanlate, Igbo-Ora, Igangan, Tapa, Aiyete and Idere. This sub-group derives its name from "Ibara-pa" - meaning "the melon splits" , referring to the people's prowess at planting melon as an economic crop. The Ibarapa still remain a farming people to this date and have acquired a distinctness in melon cultivation which sets them aside from the Oyo from which they are believed to have been largely derived. They farmed mainly in melon and other legumes such as cowpea, pigeon pea and some cash crops. Their hunting activities were limited to the forested patches of their largely open grassland territory. The earliest settlers were the people of Oniki whom subsequent settlers met there especially at the fall of Oyo empire (c.1800) and Owu (c.1821) (Mabogunje & Omer-Cooper, 1971). Subsequent settelments in Ibarapa territory were also peopled by Nupe (especially at Tapa);Ijesa and Oyo migrants. They are UNIVERSITY OF IBADAN LIBRARY 56 normally classified with the "Oke-Ogun" people, especially because they are settled northwards of the Ogun river from where they had to fight several survival wars against marauders especially the Nupe, Borgana, Abomey and Oyo. Eruwa, one of its settlements grew as a centre for yam cultivation. Lanlate, another settlement was peopled by the migrants from "Ilanla", hence its name "Ibi Ilanla te do" - meaning: "the place the Ilanla found". Igbo-Ora was founded as a farmland settlement and was peopled mostly by farming migrants. Igangan was founded by the Oniki said to have come from Ife. Tapa was predominantly peopled by the Nupe migrants hence, its name. They, however, got absorbed language-wise into the autochthonous population. Aiyete was founded as a coglomeration of smaller settlements hence its name: "Ibi aiye te" -meaning, "where the world (people) found". Idere was founded by the Onidere, an Oyo migrant. If e : The Ife are located today in Oranmiyan local government Area and its immediate districts in Osun State where they probably have been by the 5th century (Ryder, 1984) even though occupation there is reported as having taken place in at least two successions: the first up till about 1500 A.D. and the reorganisation subsequent to UNIVERSITY OF IBADAN LIBRARY 57 this decline (Ryder, 1984). The Ife are believed to have met the autochchonous Ugbo (or Ubo) dwellers in this territory on their arrival and the traditions of clashes related refer to the struggle for control that ensued between both groups over land and leadership. Ile-Ife was said to have been the major spiritual and political centre of the Yoruba between the 9th and 12th century (Willet, 1967). Ife would seem to have been subject to successive peopling from sources which seem to include: Ila, Oyo, and even Oba-Ile near Akure which probably antedated the last settlement (Smith, 1988). Iwase who is said to have led the earliest migration to Ife met Oba Erinrin, Esumare of Ife there. (Odukoya, 1968). The Oduduwa leadership was said to have emerged after succeeding in the leadership tussle with the aboriginal people at Ife (Atanda, 1980). The Ife society of then was very organised as reflected in the considerable work of art: bronze figures and terracottas. The Ife have been farmers of cash crops (cocoa, kolanut and cashew) and cereals, the patterns of which featured prominently on their pottery from archeological recoveries. Maize cob patterns were also a major feature of recoveries from the occupation phase of around the 15th century (Ryder, 1984). UNIVERSITY OF IBADAN LIBRARY 58 Ec?ba: The Egba are found in Odeda, Owode/Obafemi, Ifo, Abeokuta North and Abeokuta South local governments of Ogun State. They are also found in parts of Agege Local Government of Lagos State. The Egba, whose territory once extended beyond Ibadan area (Mabogunje and Omer-Cooper, 1971) are known to have been in possession of that territory before at least, the 15th century when the earliest colonial visitors encountered them. The Egba are usually said to have been derived from two sources: mainly the Egba Oke-Ona and Egba Gbagura from Oyo, the Egba Ake and Egba Owu from Ile-Ife and Orile-Owu respectively and are believed to be in the main to be offshoots of the Oyo (Biobaku, 1990) especially because they were part of the Oyo empire until its collapse in A.D. 1800. They probably were the earliest settlers of their present territory. The term "Egba" is a contraction of the original name of "Egbalugbo" or "wanderers towards the forest" (Smith, 1988) with a territory stretching from Ijaiye, near Ibadan (northwards) around River Oba and to Ebute-Meta (southwards) , then from Ijebu territory (eastwards) to Ipokia and River Yewa (westwards). The Egba kingdom existed as a federation, made up of four provinces: Gbagura, Ake, Oke-Ona and Owu. Of these, Gbagura was the UNIVERSITY OF IBADAN LIBRARY 59 largest with 144 towns, 72 of which was under the Onigun of Ilugun. The Owu came to Egba territory at the destruction of Owu-Ipole in Oyo empire, around 1821 under the Olowu with towns such as Erunmu, Okolo, Owu (capital) and Mowo (Ajisafe, 1972). Despite claims of Ile-Ife derivation, the Egba would seem to have been migrants from the nothern parts of Yoruba territory especially near Oyo. Oyo rule over the Egba was terminated by the Lisabi-led revolt between 1890 - 1897. / The Egba were hunter-gatherers during their early settler days as "wanderers in the forest " (Biobaku, 1957) since when they have advanced into farming in root crops which they process into food products such as "Lafun" (Cassava flour). Egbado: The Egbado are found in the Egbado division (which includes Egbado-North and Egbado-South Local Government Areas) in Ogun State and appear to have been here (Fig. 2) before the 12th century (Atanda, 1980) by which time Benin influence reached this territory with a mixture of settlers said to include: the Anago, Popo, Sabe, Ketu, Ohori, Egun, Benin, Ife, Oyo, Mahin, Awori and the Idassa. The term "Egbado" was originally used to describe the Yoruba sub-group settled near the River (Yewa) and it means: "Egba do" or "wanderers near the River (Yewa)" who were under Oyo rule up till UNIVERSITY OF IBADAN LIBRARY 60 its demise in 1800 A.D. (Folayan, 1967) with Badagry becoming tributary to Lagos in 1830. The Egbado were hunter-gatherers as well as farmers of distinction. The womenfolk process cereals and cassava while a few \ are engaged in fishing along the Yewa river and other major streams. Awori: The Awori presently inhabit Ado-Odo/Ota Local Government of Ogun State, the Lagos Island, and parts of Ojo and Badagry Local Government Areas of Lagos State. They have living in their midst, some Egun (another non-Yoruba subgroup). They are believed to have come mainly from the norhtern parts of the Yoruba territory, especially Ile-Ife. According to historical sources, the Awori, an itinerant people, were emissaries of Oduduwa who came annually to fulfil his spiritual behests of offerings on the Ogun River (Smith, 1988). Oral traditions has it that a clay plate of offerings normally terminated the annual rituals and that at one of such festivals, the plate which traditionally stays afloat the river suddenly sank hence the ethnonym: "Awori"meaning: "the plate sank" (Atanda, 1980; Fabunmi, 1985). Apparently, they were the earliest settlers in the sandy expanse that eventually became Lagos; settling first at Iseri UNIVERSITY OF IBADAN LIBRARY 61 near the Ogun River bank under the leadership of their head hunter, Ogunfuminire, whose lineage is said to be from the royal house of Oduduwa at Ile-Ife. The Awori would seem to have been migrants from Ile-Ife but seem to be contradicted by the fact that they owe their royal house largely to the invading Benin expedition of between 1603 and 1861 (Egbarevba, 1960) especially on Lagos island. The Awori, possibly because of the nature of their habitat, are adept at fishing while they, practiced some subsistent farming on their sparse landed areas. Their fisherfolk population also engaged in trading, interacting with the Edo, Mahin (from Ilaje territory) , the Ijebu, Egba, Egbado, Egun and Anago. They were said to have engaged in some hunting-gathering as their oral traditions revealed, but were limited by the swampy forest fringes of their territory. Remo: The Remo are located in Remo division made up of Sagamu and Ikenne Local Government Areas of Ogun State and parts of Ikorodu Local Government Area in Lagos State. It seems that they have been in this territory somewhere between the 9th and 16th centuries at a time when Ikorodu migrants from Remo encampments arrived there (I.D.A., 1991). They (Remo) UNIVERSITY OF IBADAN LIBRARY 62 apparently derive from three main sources: i) Iremo quarters, Ile-Ife (Remo Mirror, 1987); ii) Ijebu-Ode (Ogunkoya, 1956); iii) Ugbo in Ilaje territory (I.D.A., 1991). The migrant Remo (mainly Offin, Makun, Epe, and Soyindo) met the autochthonuos people of Ilara (under the leadership of Alara) in this territory, between the 15th-16th century. According to settlement historical sources, the earliest inhabitants in Remo territory were followers of Arisu (leader of a second migration into Ijebu-Ode) and a brother of the patriarchal Ijebu-king, Olu- Iwa believed to have arrived at about the 9th century (I.D.A., 1991). They settled first at Ilara under the Alara of Ilara hence, the term: "Ijebu to Alara mo" later said to have been shortened to "Ijebu-Remo" meaning: "the Ijebu that Alara is moulding". Another tradition says that the leaders of the Remo sub-group came from "iremo quarters of Ile-Ife (Remo Mirror, 1987) hence the name "Remo". The Remo constitutes the second largest group of the Old Ijebu kingdom and were subjects of the Akarigbo at Offin alongside with the Ewusi of Makun, Elepe and other Remo Obas. Sagamu developed as an important defence outpost which became a federation of 14 Remo settlements by 1872, although the pact was UNIVE SITY OF IBADAN LIBRARY 63 supposed to include thirty three small towns. The 14 settlements included: Offin, Makun, Ado, Epe, Batoro, Oko, Raniken, Igbepa, Ibido, Ipoji, Ijagba, Latawa, Sonyindo, and Ijokun. Whereas, the iremo claim seems to suggest that the Remo belonged to the pre-Obanta (12th-14th) century migrant group, the fact that the preceeding Alara (15th - 16th century) came earlier than their royal migrants in 1866 led by Oba Igimsoje seem to suggest that their royal leadership were probably of the later stream of migrants from Benin/Ondo territories of between the 15th - 16th centuries who sojourned in Ijebu-Ode before moving into this territory to dominate an autochthonous population. The Remo traditionally engaged in farming, planting cash and food crops. Kola and Cocoa were major crops of economic value they cultivated. They also engaged in extensive processing in cassava (Gari) and cereal products with which they engaged in trading, initially through barter with water-faring travellers (including colonialists) around Ikorodu. Ijebu: The Ijebu are located today in the Ijebu division of Ogun State, and the Ibeju-Lekki, Eti-Osa, Ikeja, Somolu, Epe, and Ikorodu local government Areas of Lagos State. Oral traditions suggest that the leader of the Awujale dynasty, Olu-Iwa arrived in UNIVERSITY OF IBADAN LIBRARY 64 Ijebu in the 9th century. This is questionable given that the same traditions report that Olu-Iwa has sojourned at Ife with Oduduwa on his way to Ijebu and the fact that Oduduwa's Ife does not predate the 10th century. The Olu-Iwa entourage met the Idoko, Idokunnusi and the people of Eredo in this territory on arrival whom they eventually came to control in a territory originally delimited by the historical ramparts: "Eredo" (Lloyd, 1959). The term "Ijebu" is said to mean a "flourishing essence" according to popular folklore (I.D.A., 1991). One school of thought claims that the Ijebu are descendants of the Jebusites mentioned in the Holy Bible (Genesis 10:16; I Chronicle 11:14), according to Odukoya (1963:5) The second migration was led by Ajogun Ogboroganda (otherwise called "Obanta") who is said in oral tradition to be the grandson of Olu-Iwa and son of Oduduwa and Gborowo (Olu-Iwa's daughter) from Ile-Ife. It was he (Obanta) whose military abilities opportuned him the chance to consolidate the Awujale dynasty (Ogunkoya,1956). Another migration from Benin territory (mainly Ijamo) was led by the 10th Awujale Obaruwa, alongside some lesser one from Ondo territory. These were said to have assured some solidarity which sustained the Ijebu during the 19th century Yoruba wars, especially with arms supplied by European traders with whom they were UNIVERSITY OF IBADAN LIBRARY 65 acquainted (Ayandele,1992). Obanta's arrival in Ijebu between the 12th-14th century also contradict the notion that he could have been Olu-Iwa's grandson (Ogunkoya, 1956). His migration from the direction of the Benin/Ondo territories seems to support a probable Benin or Ondo (or Ilaje) relationship. The autochthonous population in Ijebu territory were hunter-gatherers with practices of some subsistent farming in cash and food crops. They traded extensively with early colonial visitors in textiles and other farm products at Ejirin, said to be West Africa's largest market at that time. (I.D.A., 1991) . Eko: The Eko (or Eko-Yoruba) as well as the aboriginal Awori inhabit Lagos island, mainland and adjoining areas like Ikeja, Ebute-meta, Ido, Yaba, Isolo, Apapa, Mushin and Agege in Lagos State. The Eko comprise an amalgam of descendants from the Awori, Ijebu, Mahin, Benin, Nupe, Ife, Ijesa, Egun, Anago, Egbado, Ketu, Egba, Creoles of Sierra Leonean extraction and some Brazilians. The term "Eko" meaning:"camp" is a Benin (Bini) word, coined by the military expedition of Oba Orogba about 1603 A . D . (Egharevba, 1960) which established a war-camp on Lagos island to further its expansionist interests. The Benin remained in control up till 1861 when the British came in to establish colonial rule (Egharevba, UNIVERSITY OF IBADAN LIBRARY 66 1960; Smith, 1988) The other migrants of the Eko possibly met the aboriginal Awori whom they subsequently outnumbered especially as a result of trade-influenced settlements in and around the Lagos island. The Eko would appear to have been present by at least, the 15th century when the earliest Portuguese visitors came in 1492. Lagos, derived from "Lago de Curamo" was first cited in a Portuguese map of 1845 and writing of Darte Pacheco (1931) in "Esmeraldo de situ orbis" (Smith, 1988). The Eko, despite its Awori aboriginal derivation would seem to have been derived from various sub-group sources including Benin. The royal house of Ife claimed by the Awori would seem to have been probably more due to the Benin royal house of Oba Orogba (Egharevba, 1960) . The fact that the Eko is variously derived would imply that an amalgam of such sources of derivation is now obtainable as against the possibility of an Awori aboriginal expression. A primary occupation of the Eko is fishing, having acquired their skills from the Mahin, Awori, Egun, and Ijebu fishing communities. They engaged in farming where substantial land afforded it. Their position as intermediaries between colonial visitors and other people as from the 14th century predisposed them to engage in a trading culture yet unsurpassed by other Yoruba sub- UNIVERSITY OF IBADAN LIBRARY 67 groups. Ilai e : The Ilaje, found today in the Ilaje division of Ondo State, are believed to have been there since the 8th century being one of the first settlers alongside the "Ifore" and "Idoko". Their major towns include: Atijere, Igbokoda, Igbolomi, Igbo- egunrin, Okesiri, Mahin, Aiyetoro, Ugbonla, Ugbo, Idi-Ogba, Zion and Ereke. They have lived successfully with their neighbouring sub-groups: Ijo, (or Ijaw) Ondo, Ikale, Benin, Ijebu and the Itsekiri. With their homestead amongst the creeks, canals, lagoons, estuaries and the seashore, the Ilaje are mainly fisherfolk and water bound traders having become acquainted with the art of water exploration for centuries. Their settlements are divided into two categories: Mahin and Ugbo (Smith, 1988) . While the Ilaje, like other Yoruba sub-groups would claim Ife derivation their sources of derivation would seem to be relate to the "Okun Yoruba" and other related populations North-East of Yorubaland where the "proto-Yoruba" known to be acephalous (Smith, 1988) are said to have been derived. The fact that the Ilaje have no genuine royal traditions seem to contradict any strong Ife or Benin relationships. The Ugbo category are administered under the Olugbo of Ugbo. UNIVERSITY OF IBADAN LIBRARY 68 There is tendency to believe that the Ilaje (especially the Ugbo) are related to the earliest, pre-Oduduwa forest settlers at Ife with whom he had to struggle for the control of power and land subsequent to his domination at Ife. Ikale: The Ikale who presently live behind the creeks, lagoons and coast-line in the Okitipupa Local government area of Ondo State are said to have been there at least, by the 10th century. Apparently, they had relations with the Benin under Ewuare the great and may have been derived from Ife, Ondo and Benin sources. The Ikale have had centuries of trading relationships with their neighbouring sub­ groups such as: Ondo, Ilaje, Benin, Ijebu and the Itsekiri. They were supposed to have left Ile-Ife during a festival when drumming was prohibited, hence, the name: "Kale" which means "no drumming". This therefore, became the sub-group's name: "Ikale" (Fabunmi, 1985). Their major towns include: Okitipupa, Ode-Aye, Ode-Irele, Igbotako, Akinfosile, Ilutitun, and Ebute-Irele. The Abodi of Ikoya exercised supreme traditional authority on the Ikale in the pre-colonial era (Smith,1988). However, the fact that they are largely acephalous seem to contradict the strong Ife relationship suggested by Fabunmi (1985); the absence of strong UNIVERSITY OF IBADAN LIBRARY 69 royal institutions would rather support probably the peopling by an autochthonous population related to the North-East 'Okun Yoruba' with later (15th-16th century) influence from Ife and Benin. They farmed in cash and other crops while their women processed many food products. They have townships that were self- governing and independent, with some senior age-sets as the leadership. Ondo: Traditions of the Ondo who live presently in the Ondo Local Government Area of Ondo State suggest that they have been there since at least, the 10th century when the "Ifore" and "Idoko" arrived there. They are believed to have been derived from Ife mainly, and then Benin (partially) . According to settlement historical sources, the "Ifore" and "Idoko" were hunter/gatherers, who settled at Ededo or Ode-Ondo, the present site of Ondo. The term "Ondo" means "settlers" (Smith, 1988) . The royal dynasty from Ife established by "Pupupu" came under the leadership of Uja and Akunnara, two of Oduduwa's warriors. Under Airo, the kingdom was put on a firm footing (Atanda,1980). The royal house of Ondo that is said to be of Ife derivation shows greater Benin influence. The possibly that the settlement UNIVERSITY OF IBADAN LIBRARY 70 pattern in Ondo territory has been greatly influenced by both Benin and Ife is not in doubt. The Ondo are famed in all of Yorubaland for their hunting prowess which seems to derive principally from their experiences as one of the foremost sub-groups that invaded the forested areas as hunters and gatherers. They farm cash and food crops presently and process palm-oil, cereals and cassava. Akure: The Akure are located in the Akure Local Government Area of Ondo State, Nigeria. They are probably one of the aboriginal settler sub-groups of the Yoruba. They are said to have been derived from Oba-Ile (the domain of the important excavation site of Iwo-Eleru) Atanda (1980) claims that Oba-Ile's peopling predated the settling at Ile-Ife, and it has been suggested on these grounds that they have been in their present abode since at least, before the 5th century, when they started to move out beyond the immediate forest environment of Oba-Ile for greater farmland and hunting/gathering access. According to the people's oral tradition, farming, especially in food and cash crops; and hunting seem to have been very important activities of the early settler Akure populations largely UNIVERSITY OF IBADAN LIBRARY 71 because they were endowed with fertile, forested arable lands upon which such crops could thrive. Hunting/gathering certainly grew from the early days of proliferation from Oba-Ile ( a village domain near Iwo-Eleru rock shelter) and Epe. The Akure are believed to have been derived from at least, four major sources: Oba-Ile, autochthonous Isikan and Isolo; then the Edo (or Benin); the latter are today found in Igiso, Eyinke and Oritagun quarters under the leadership of the Olotu-Ekiran or the Adowere (or Edowere) . The Edo derived are styled the "Ado-Akure" or "Edo-Akure" to this day (Smith, 1988). The name "Akure" derives from "Akun-re" which means: "bead cut" and apparently resulted from the fact that the wrist beads (Akun" of Omoloju, son of Iyangede of Epe), cut at the spot when he was trying to clear a bush-path on a farm between Isikan and Oke-Aro junctions on Arakale road. The first "Oba" of Akure was said to be the grandson of Oduduwa. That the Akure are derived from some settlements that pre­ dated Ile-Ife would seem to suggest that they are related to the "Proto-Yoruba" populations of the North-East of Yorubaland (Smith, 1988) . The influence of Ife, Ijesa, Ekiti and Benin would seem to have arrived much later. Owa Atakunmosa, seventh ruler of the Ijesa, while on a journey UNIVERSITY OF IBADAN LIBRARY 72 to exile in Benin passed through Akure and gave his daughter in marriage to the Oba Ajanpada Oriya. The son called Ogunja Olufadeji, on ascending the throne of Akure changed his title from Ajanpada to "Deji" of Akure which is the title in use up to the present day. Owo: The Owo who are believed to have been mainly derived from Ife and Benin sources probably came to their abode in Owo Local Government Area of Ondo State by the 11th century (Ashara, 1951). They met the "Efene" on their arrival there (Ryder, 1984) under the rulership of EJefene (M.O.I., Ondo State, n.d.) According to historical sources, the founding father of i today's Owo was Ojugbelu (or Ojugbolu) from Ife and his reign has been put in the begining of the eleventh century (Ashara, 1951). Ojugbolu was said to be the younger brother of an Oba of Benin, both of whom left Ile-Ife at the same time (M.O.I., Ondo State, n.d). On leaving Ife, Ojugbelu halted at Uji (or Ujin) and then at Upafa (or Utapafa Hill); south of the present kingdom (Atanda, 1980; M.O.I., Ondo State, n.d.; Smith, 1988). from Utapafa, he moved his followers to Oke-Imade (Atanda, 1980) , then to Igbo Ogurata (or Igbo Oguwata) now called Okiti Asegbo, centre town of UNIVERSITY OF IBADAN LIBRARY 73 present Owo (Atanda, 1980). The group under the Olowo Imade is thought to have finally met the "Efene" at Okiti Asegbo on arrival there (M.O.I., Ondo State, n.d.), they initially lived amicably together but later had to settle the issue of supremacy by force of arms. Cultural similarities between Benin and Owo are evident in their brass-casting, wood sculptures, terracota and Ivory described as intermediate between Yoruba and Benin styles (Smith, 1988). The fact that autochthonous Efene were met and dominated by royal groups (warlords) said to be of Ife and Benin sources mainly points to the fact that royal traditions came after the 10th century to most Yoruba sub-group territories. The autochthonous populations would seem to have been derived through migrations from local populations related to neighbouring sub-groups. The Owo particularly reflect substantial Benin influence in its royal house and art traditions. The Owo are hunters, farmers and metalsmiths. They farm in arable and cash crops of economic value. Ii esa; The Ijesa are said to have been in their present abode (Ijesa division of Osun State) since about the 10th century. Their traditions indicate that they are derived primarily from Ife although contacts with Benin is also well established during UNIVERSITY OF IBADAN LIBRARY the reign of Atakunmosa (7th ruler of the Ijesa) whose son also ruled in Akure as Deji (Smith, 1983). The Ijesa met an autochthonous population who were the people of IIowa, Hare and Onila whom the Ajaka migration met there (Smith, 1983). The Ijesa kingdom was said to have been founded by Ajaka (or Ajibogun), a son of Oduduwa (Smith, 1988) who successfully got him (Oduduwa) sea-water to help treat his blindness. Whereas, Ajaka led his followers to a place called Igbadaye where he died (Atanda, 1980), his son, Owa Okile apparently extended control to a place called IIowa, then Ilemure (re-named Ibokun) where he displaced Ita, a king he found already installed there. While at Ibokun, he also brought under his control the town of Ilare, whose ruler (Alare) claimed Ife dIescent. The next Owa, Owari moved to Ilaye (Atanda,1980) which came to be called Ipole-Ijesa after his death. The fifth reign, brought Owa Oge who chose Ilesa, whose original ruler he made second in rank and named Obanla. Other rulers around Ilesa were similarly subjugated, giving rise to what came to be called the Ijesa kingdom (Atanda,1980) . The Ijesa claim of derivation should include: Oyo (Ibadan), Benin and Akure apart from Ile-Ife since populations from these other Yoruba sub-groups have been known to settle within their territory. The Ijesa would therefore seen to have been derived from UNIVERSITY OF IBADAN LIBRARY 75 these sources apart from the aboriginal population met in the territory. The Ijesa had to resist pressures from Nupe, Benin and Old Oyo. They maintained their independence until they were overrun in the nineteenth century by the Ibadan who rose to power at the fall of the Oyo kingdom (Atanda, 1980). The Ijesa have hunting/gathering traditions which they still maintain till today. They farm in cash crops such as Cocoa, Kola and Cashew and food crops, particularly "Okro" which is still a major feature of their farm-based rural economy. The women process food in pots which they make extensively hence the ethnonym: "Ijesa" meaning: "the pottery makers". Smith, (1988) contends that it may also mean "town of the gods". Ekiti: Ekiti traditions indicate that the autochthonous people in the Ekiti division of Ondo State and in the Ekiti Local Government (alongside the Igbomina) in Kwara State were living in their present homeland by the 14th century. They principally descended from the aboriginal Ilesun and then Benin (or Edo) settlers; from Ife and Benin sources. The term "Ekiti" denotes: "a country of hills" being a good description of the territory's physical features. UNIVERSITY OF IBADAN LIBRARY 76 Ekiti kingdoms were founded around towns with crowned Oba (Ilu Alade) and said to be city states limited by mountainous physical features, each claiming descent from Ife via Benin (Smith, 1988). These were the sixteen (16) Ekiti principalities, which were economically linked but politically independent of one another. They were: Owore led by Otun; Ijero under the Ajero; Ado under the Ewi (or Elewi);Ikole under the Elekole; Ara under the Alara; Efon Alaye under the Alaiye; Ido under the Olojudo; Ogotun under the Ologotun; Igbo-Odo (Imesi) under the Oloja-Oke; Oye under the Oloye; Omuo under the Olomuro; Ire under the Onire; Ise under the Arinjale; Ita under the Onitaji and Akure which later opted out, to be on its own. Benin imperialism prevented Ekiti unity considerably before 1800 (Atanda, 1980) . However, under Ibadan military pressures, the 16 states formed Ekiti parapo in the 19th century. The Ewi of Ado- Ekiti (formerly named "Awamaro" - restless one) came through Benin hence the term "Ado" (equivalent of Edo) is used as prefix. The fact of Ilesun and Benin derivation sources of the Ekiti seem to suggest limited Ife influence. The royal house of Ado-Ekiti and even the patriarchal "Ewi" seem to have been principally of Benin influence; a fact that is reflected in today's royal ornaments and regalia of the Ewi of Ado-Ekiti. UNIVERSITY OF IBADAN LIBRARY 77 The Ekiti have been hunters/gatherers within their hilly domain. They also farmed a lot of food and cash crops of considerable arable land available to them. Akoko: The Akoko are presently in the Akoko Local Government Area of Ondo State of Nigeria (Table 1; Fig.9). They live on the hilly outline of the North East Yorubaland fringes; a situation which provided them with immense security in the days of frequent warfare with neighbouring sub-groups. They have been in this territory since at least, the ninth century, as a confederation of independent village settlements, each with a political administration and territory which was religiously guarded (Smith, 1988). The Akoko are believed to have been largely derived from three main courses: Yoruba (often including traditional Ife connection), Afenmai and Benin, (Smith, 1988/89) ; and to have become an independent entity circumscribed territorially (Atanda, 1980) due to subsequent interaction and negotiations between the different settler-village dependencies. The Akoko seem to have been derived from the "Proto-Yoruba" (Smith, 1988) in addition to Afenmai and Benin sources. The fact that their territory was more accessible to populations around the North-East of Yorubaland appear to imply that they have had a UNIVERSITY OF IBADAN LIBRARY 78 little Ife influence. The acephalous nature of the sub-group also seem to show that Ife and Benin influences came late to the sub­ group's territories. Iiumu; The Ijumu (with sub-units of Gbede, Ikiri, Ayere and Ogidi) living in Oyi Local Government Area of Kogi State (Fig.5) are said to have been here from at least, 3000 Y.B.P. (Bolorunduro, 1990) and were descendants of the hill-living people around the North- East Yorubaland or the "Okun" Yoruba (Ijagbemi). They are said to be the autochthonous people indigenous to this area of the hill deities or "Ebora" (Oyelaran, 1991). The Ijumu constitute one of the principal sub-groups of the North-East Yoruba found around the Niger-Benue confluence and very much related linguistically to the Itsekiri and Igala (Smith, 1988). The Ijumu, Yagba, Bunu and Kabba (or Owe) are part of the "Proto-Yoruba" of the North-East Yorubaland; the area of the archaeological work of Iffe-Ijumu where Oyelaran (1991) dated palm kernel fragments to 2210 + 80 Y.B.P. The Ijumu were said to be hunter gatherers in those early days and it seems that they first came to this area under the leadership of the Owa who first settled in Gbede area. Aiyetoro emerged as an active centre of the kingdom, controlling 17 villages. The other major towns in the territory UNIVERSITY OF IBADAN LIBRARY 79 are: Aiyegunle, Odokoro, Iyah, Ogidi, Iyamoye and Aiyere. Iyara is the traditional capital of the Ijumu territory. They are farmers and metalsmiths presently and their women process palm-oil and kernel oil in addition to products from cereals and stem tubers. Kabba: The Kabba (or Owe) are found in present day Kabba town and its township districts in the Oyi Local Government Area (Fig. 5) of Kogi State, such as: Gbelenko, Aiyetoro-Egunbe, Okedayo, Onakiti and Egbeda. Like other "Okun", the Kabba were essentially acephalous (Ijagbemi, 1987) and the notion of an Ife migration is regarded as "charter myth". They are closely related to the Oworo who live alongside them in the area with other "Okun" Yoruba \ notably Bunu, Ijumu and Yagba (Ijagbemi, 1987) who are believed to have been there since at least, 3000 Y.B.P.. The Kabba are indigenous to this area among the autochthonous people termed "proto Yoruba" (Atanda, 1980; Smith, 1988). The name Kabba is believed to have been derived from "Oke- Aba", the site of the original settlement. Whereas the Kabba have been known to be indigenous to this area with little or no influence from Ife, the possibility of some derivation from neighbouring Ebira, Nupe Benin, Igala and other "Okun" Yoruba cannot be ruled out. UNIVERSITY OF IBADAN LIBRARY 80 The Kabba are farmers, having established a tradition of hunting and gathering over the years alongside subsistence farming. The women process palm-oil, kernel oil and cereal products. Bunu: The Bunu (Abinu or Abunu) are of Oyi Local Government Area of Kogi State (Table 1; Fig.5). They claim to have been in this territory by at least, 3000 Y.B.P. and to have been derived principally from the hilly range of areas around the North-East portion of the Yoruba territory, around the Niger-benue confluence (Ijagbemi,1987). The Bunu are among the earliest settlers in the North-East portion of Yorubaland, an area said to be the home of "proto-Yoruba" (Atanda, 1980; Smith,1988). They are part of autochthonous people Iof this area and are essentially acephalous (Ijagbemi,1987). According to settlement historical sources, the people have always been there with hardly any link with Ife (Bolorunduro, personal communications, 1990), except for recent claims of relationship by some chiefs, possibly stemming from migrations said to have been from Ile-Ife and Oyo-Ile (Smith, 1988). Majority of the Bunu have been there before the advent of Oduduwa (Smith, 1988). There is ample linguistic relationship with some other neighbouring people such as Igala, Nupe and Bariba. The Bunu are essentially farmers even though a tradition UNIVERSITY OF IBADAN LIBRARY 81 of hunting/gathering had existed. The processing in food and cash crops is reasonably prevalent especially among their womenfolk. Palm-oil processing is a major occupation here. Yaqba: The Yagba, in the Yagba Local Government Area of Kogi State (Fig. 5) constitute the largest of the "Okun" Yoruba said to be indigenous to the North-Eastern part of Yorubaland since at least 3000 Y.B.P. (Ijagbemi, 1987). The major Yagba settlements include: Isanlu, Egbe, Odo-Ere, Igbakuru, Odo-Eri, Mopa, Amuro, Ijagbe, Okere, Ogga, Okunran Ejuku, Jege, Ilae, Ogbom, Ejigba, Akata and Ololoke. They were tributary to the Nupe who appointed a local administrator: "Ajele" or "Ogba" for the prompt collection of tributes (Ijagbemi, 1987). The founder of the Yagba kingdom is reported to be a woman who was affectionately called "Iya-Agba" meaning: "elderly woman" by he people. The ethnonym: "Yagba" was derived from "Iya-Agba". She had settled her people at Akata at first (Bolorunduro: personal communications, 1990) . The earliest leaders (priest and chiefs) of the Yagba were said to be the descendants of this great woman. They eventually dispersed into the territory to find other towns. Though there is a considerable connection between the Yagba and other "Okun" Yoruba yet the influences of other neighbouring UNIVERSITY OF IBADAN LIBRARY 82 peoples is likely to have been important in the settlement pattern. The fact of their being acephalous seem to suggest little or no Ife influence. Kelae for instance, found Egbe as a centre of great agricultural activity hence the name: "E gbe" meaning: "cultivate". The Yagba practiced hunting/gathering for centuries in the hilly range of the North-East confluence area of Yorubaland. They are presently farmers especially as evident in the name of one of their major towns: "E gbe!" The womenfolk engage in palm-oil and kernel oil processing alongside the preparation of cereal food products. Igbomina: The Igbomina (or Igbonna) who are at present in Irepodun and Ifelodun Local Government Areas of Kwara State, have apparently been living there since at least, the 11th century at the advent of the earliest settlers from Oyo. They comprise a mixture of Oyo settlers of successive migrations, and some claimants of Ife and Ila derivation. The name Igbomina (or Igbonna) derives from "Ugbo mo ona" meaning: "the wand (or stump) knows the way" : an indication that the staff or wand used by their ancestral leader was useful in finding their way to their present domain. Their domain bestraddles UNIVERSITY OF IBADAN LIBRARY 83 the forest and the savannah (Smith, 1988). The ancestor of the Olupo called Igwana was said to have come from Ife but paid tribute to Alafin. Igbomina/Oyo relations are said to have been long-standing. The Igbomina are interspersed by some Ekiti. They are regarded as being Oyo with Ekiti sympathies (Smith, 1988). The major contradiction in the setting of the Igbomina would seem to be the fact of their royal traditio said to be of Ife derivation and paying tribute to Alafin. The suggestion that they are Oyo with Ekiti sympathies appear to show a mixture of Oyo migrants with neighbouring Ekitis who probably submit to Ife derivation because of common Ila descent of some of its migrant which they share with Ife. As part of Ila kii ngdom, the Igbomina had towns such as: Oke- Ila, Ora, Oke-Ewu, Aran, Apa, Oro, Ajase, Isin, Igbaja. All these towns recognised Ila as their traditional headquarters (Atanda, 1980) and remained under the Orangun of Ila until the nineteenth century when their solidarity was shattered by Ilorin imperialism (Atanda, 1980). The principal ruler of the Igbomina appears to be the Olomu of Omu-Aran who is today overshadowed by the Olupo of Ajase-ipo (Atanda, 1990) due largely to some powerful traditional oil in the possession of the latter. UNIVERSITY OF IBADAN LIBRARY 84 The Igbomina were harrassed by Ijesa and Nupe raiders on their territory. Their position was maintained by dint of furious activities which they had consolidated with Oyo. The Igbomina are farmers with some hunting/gathering background. Their women processed many farm products into a variety of edible foods. Linkages in Yoruba History Available linguistic, archaeological, and historical evidence thus appear to suggest that the Yoruba have had close interactions with a number of its neighbouring language sub-families: Nupe, Bariba, Bassa, Benin, (Edo), Igala, Ebira (or Igbira) , Ijo (or Ijaw), Itsekiri, and Urhobo. Horton 1979: 82) states in this regard as follows: i A n c e s t r a l Y o r u b a p o p u l a t i o n was p a r t o f a l a r g e r d i s p e r s a l , n o t fro m t h e M i d d l e E a s t , b u t from t h e g e n e r a l a r e a o f t h e N i g e r - B e n u e c o n f l u e n c e . Smith (1988:11) on his part assesses the linkages and summarises thus: I f t h e b r o a d c o n c l u s i o n f r o m t h e l i n g u i s t i c e v i d e n c e i s a c c e p t e d , t h e n t h e t r a d i t i o n s o f o r i g i n w h i c h a r e p r e s e r v e d by t h e Y o r u b a seem t o r e f e r t o movem ents o v e r o n l y c o m p a r a t i v e l y s h o r t d i s t a n c e s o r l e s s p r o b a b l y , to t h e a d v e n t o f a s m a l l g r o u p o f c o n q u e r o r s who q u i c k l y became a s s i m i l a t e d w i t h t h e i r new s u b j e c t s . I t seems l i k e l y t h a t i n e i t h e r c a s e movement was from t h e g r a s s l a n d , UNIVERSITY OF IBADAN LIBRARY 85 where cultivation was earlier advanced and where there might be some population pressure, into the forest, and the legend of Oduduwa and the royal progeny of Ife may be a distant memory of such a movement. To speculate beyond this point is hazardous, since new myths are all too easily created. There has, for example, been a tendency in recent writing about African history to attribute the origin of most states to the conquest of the people of one culture by people of another, postulating a sharp distinction between the rulers and the ruled. Stereo typing of this kind usually results in over-simplication and other distortions, for while most states in the world developed under the stimulus of older states, their origins are many and diverse. Meanwhile, new materials on the subsequent history of the Yoruba is being uncovered and as more is established about what may be called their middle ages, this should in turn shed light on earlier times. But this kind of reconstruction has special dangers for the historians, whose study permits generalizations but has no laws and whose material is unpredictable humanity; extrapolation unsupported by evidence should usually be left to scientists and mathematicians. Early Yoruba history now waits, not over-hopefully, upon archaeology and its ancillary sciences. UNIVERSITY OF IBADAN LIBRARY CHAPTER THREE BIOLOGICAL METHODS AND ANALYSIS Biological Methods in Studying Human Groups The Biological aspects of the data on a population, especially one that is known to have lived together for some time such as the Yoruba, serves to provide some information on the extent of interbreeding. Biological data are valuable especially where they are required to elaborate on the archaeological, historical, cultural and linguistic evidence available (Hiernaux, 1974). They will as well help to reveal the extent of expressivity of the influence of exotic populations which historical and cultural accounts are often found to suggest. Biological data are able to also show the extent of internal wandering (or active interbreeding) that has progressed within a population under study. The extent of biological diversity is also detectable in the assessment of the biological evidence with one or more populations (Hiernaux, 1974). Biological Data in West Africa: Biological data in terms of skeletal remains in West Africa and particularly in the area classified as Yorubaland by historians and anthropologists, are scanty and generally not often well 86 UNIVERSITY OF IBADAN LIBRARY 87 preserved for well-known environmental reasons such as high acidity and rapid oxidation. A few notable finds are available which can assist in the biological reconstruction of the past, generally in West Africa and Yorubaland in particular. The Iwo-Eleru skull dated to 11,000 Y.B.P. and inferred to have belonged to a proto-negroid population (Brothwell and Shaw, 1971) is one of the few that may well give an insight into the antecedents of the Yoruba. Skeletal remains found may not necessarily relate in all cases to the present day population in the area as Huizinga et al (1967) found with the radiocarbon dating of Tellem cave skulls found in today's Dogon territory. Whereas, anthropometric measurements are useful in assessing biological variation Hiernaux (1974) found that environment could also influence biological characters. This, he said, could be either through the expression of the genotype or through allelic changes or frequencies in populations. He stressed that human populations can evolve independently if they exhibit considerable endogamy with little or no barrier to internal mating. Such endogamous population(s) he concluded present some suitable instances for describing human biological variation and attempting to explain such in terms of genetical evolution. Hiernaux (1974) noted that biological evidence indicates that UNIVERSITY OF IBADAN LIBRARY 88 the effects of exotic populations especially from Northern and Eastern Africa have been moderate based on biological evidence, especially as interbreeding has been highly active and the sub- saharan African populations present strong barriers to penetration. He said that recent exotic influences had played minor and localized roles in populations. He observed that other factors of genetic change; drift and selection may blur the impact of genetic admixture especially of older instances. Hiernaux (1974:55) therefore, cautions that biological characters must be relied on when trying to assess the importance of genetic mixture. This, he said, is because: The p r o c l a i m e d a n c e s t o r s o f a p o p u l a t i o n may r e p r e s e n t o n l y a " g l a m o r o u s " g r o u p whose c o n t r i b u t i o n t o t h e p r e s e n t ge ne p o o l was t r i f l i n g . . . t h e l a n g u a g e o f a s m a l l g r o u p o f i m m i g r a n t s may be t o t a l l y a d o p t e d by a l a r g e p o p u l a t i o n ; and be w i d e l y a d o p t e d w i t h a minimum o f c o r r e s p o n d i n g gene f l o w , w h i c h may h a v e been too m o d e s t t o be d e t e c t a b l e . Hiernaux (1974) also advised against unjustified pooling biases in the sampling of sub-saharan populations having noted that the level of genetic variation was very high and that only a minority of the units can be grouped. Cavalli-Sforza (1966) for his part cautions on the population acceptance of conclusions made on population structure studies, as UNIVERSITY OF IBADAN LIBRARY 39 according to him, there could always be some alternative explanations! ABO Blood groups as marker in population studies. The ABO blood group system has been found to be a very useful means of providing biological data for corroborating historical, archaeological, cultural and linguistic evidence. (Hiernaux, 1974) However, data on the ABO blood groups of many sub-saharan populations are either non-existent, scanty or unrepresentative of their distribution over known biotope. Hiernaux (1974:65) in recognition of the importance of the ABO blood group as vital markers within such populations has summarized the point thus: l When we f i n d two p o p u l a t i o n s d i f f e r i n g i n t h e f r e q u e n c y o f b l o o d g r o u p s , we know f o r s u r e t h a t t h e d i f f e r e n c e i s g e n e t i c a l : b l o o d g r o u p s a r e s t r i c t l y d e t e r m i n e d by h e r e d i t y and no c i r c u m s t a n c e i n t h e l i f e o f an i n d i v i d u a l c a n c h a n g e h i s b l o o d g r o u p . T h i s h o l d s t r u e f o r a l l s y s t e m s o f h e r e d i t y v a r i a n t s o f b l o o d s u b s t a n c e s . ABO Blood group: Antigens and Antibodies The discovery of the A, B and 0 blood groups by Landsteiner in 1901 and the fourth blood group AB, by Decastello and Sturli in 1902 helped to attain a great landmark in transfusion therapeutics (Race and Sanger, 1968). The four groups are determined by the presence UNIVERSITY OF IBADAN LIBRARY 90 or absence in the red blood cells of the blood group antigens A and B (Table 4) and therefore, the blood group of the individual is A, B, AB or 0 (O denoting the absence of A and B) (Boorman and Dodd, 1970). Landsteiner's (1901) discovery has also become an important milestone in the field of anthropology because the settlement history of a population could be correlated with blood group distribution gene frequencies (Watkin, 1966). Alongside the antigenes A and B found in the red blood cells are also the antibodies anti-A and anti-B, which occur as agglutinins in the sera of individuals whose red cells lack the corresponding agglutinogen (or antigen) Boorman and Dodd (1970). The antigen and antibodies present in! the four groups are as in Table 4. Antigens present on a person's red cells are inherited. Each antigen is controlled by a gene which is a unit of inheritance. Variants of a gene are called alleles or allelomorphs for that trait (Bell et al, 1972). Human blood group inheritance is thus governed by multiple alleles. These alleles feature in ABO blood group inheritance. UNIVERSITY OF IBADAN LIBRARY 91 TABLE 4 ABO BLOOD GROUP ANTIGENS AND ANTIBODIES Blood Group Antigens in Antibody Red Cells in Serum A A Anti - B B B Anti - A AB A & B - 0 Anti - A & Anti - B | UNIVERSITY OF IBADAN LIBRARY 92 According to Keele & Neil (1972:34), these substances are subject to Landsteiner's Law: If an a g g l u t i n o g e n i s p r e s e n t i n t h e r e d c e l l s of b l o o d , t h e c o r r e s p o n d i n g a g g l u t i n i n m u s t be a b s e n t fro m t h e p l a s m a ; i f t h e a g g l u t i n o g e n i s a b s e n t , t h e c o r r e s p o n d i n g a g g l u t i n i n m u s t be p r e s e n t . A child's blood may not be set in its true ABO type until as late as one year after birth (Keele and Neil, 1972). The Blood groups refer to the presence of certain antigens, the blood group substances on or in the red cell envelope (Bell et al. 1972) . They are inherited characteristics which mostly belong to genetically independent blood group systems. Blood group antibodies are found in the globulin fraction of the serum, and may l be immune or naturally-occurring antibodies, (Bell et a_l, 1972) . A statistical association has occasionally been found between the ABO blood group and certain diseases. Group '0' persons are much more susceptible to peptic ulcers than individuals of any other blood group while 'A' persons are more associated with cancer of the stomach (Bell, et ai 1972). Blood groups are useful for indicating parentage as they are unchanged as inherited (Boorman and Dodd, 1970). They are thus useful for deriving biological relationships through the studies of their distribution in populations, expressed as phenotypic or genic frequencies.(Table 5) UNIVERSITY OF IBADAN LIBRARY 93 TABLE 5 ABO BLOOD GROUP GENOTYPES Antigen Antibody Can Donate Can Receive Blood Genotypes in Red in to fromGroup Blood Plasma Cell 0 ii - a and b 0,A,B,A,B 0 A iAiA;iAi A b A, AB 0, A B iBiB;iBi B a B, AB 0 ,B AB iAiB AB - AB 0, A,B, AB Note: iAiB produce antigens A and B hence, they are codominant. A and B are called group - specific substances and chemi­ cally are polysaccharridos (Fig. 3). They are antigens and in the presence of suitable antibody agglutination occurs (Keele and Neil, 1972). UNIVERSITY OF IBADAN LIBRARY 94 Antigens are substances of large molecular size, usually protein, having a polysaccharide component (Fig.3) which determines the specificity, while the amino acid component determines the antigenicity; the ability to stimulate the production of antibodies (Boorman and Dodd, 1970). Antibodies are immunoglobulin and form part of the serum globulin. Antibodies to blood group antigens are not found in body fluids such as saliva and urine. However, blood group antigens may be found in body fluids. ABO substances may be found in fluids such as the synovial joint fluid, saliva and semen of 80% of a population who are termed 'secretors'. Agglutination of red blood cells is the clumping, granular appearance seen as a result of mixing cells containing the corresponding antibody (Boorman and Dodd, 1970). The agglutination of red cells takes place in two stages: (i) sensitization; and (ii) agglutination (Fig. 4). During sensitization, serum agglutinins become attached to agglutinogen on the red cell surface. The actual clumping or agglutination of the sensitized cells occur during the second stage (Boorman and Dodd, 1970). UNIVERSITY OF IBADAN LIBRARY 95 According to Boorman and Dodd (1970: 1): An A n t i g e n i s a n y s u b s t a n c e w h i c h , when i n t r o d u c e d p a r e n t a l l y i n t o a n i n d i v i d u a l who h i m s e l f l a c k s t h e s u b s t a n c e , s t i m u l a t e s t h e p r o d u c t i o n o f a n a n t i b o d y , and w h i c h , when m ixe d w i t h t h e a n t i b o d y , r e a c t s s p e c i f i c a l l y w i t h i t i n some o b s e r v a b l e way. Substances, such as poly-saccharides which may be weakly antigenic with some amino-acids contributing in some way to specificity, are called HAPTENS, often in body fluids like saliva secretion (Boorman and Dodd, 1970). Ever since the discoveries of Landsteiner (1901) and Decastello and Sturli (1902), knowledge of blood group distribution has been used as an important tool for studying human populations. Peculiarities in genic frequencies could help to relate groups with settlement history, particularly high frequency of one blood group within a population. (Dawson, 1964). Sometimes, some relationship could be drawn from the association of certain blood group frequencies in present populations and earlier ones (Brown, 1965). Groups that are anthropological appendages of others could be discovered through blood group investigation showing similar values of genic frequencies (Watkin, 1963). Garlick's (1962) maps of blood groups in Africa was a follow-up of the work of Mourant et al (1958) which he said could only be improved through detailed work that can strike out to cope with local fluctuations. UNIVERSITY OF IBADAN LIBRARY 96 Hardy (1962) found a gradual diminution in the 'B' gene frequency passing from the Yoruba to Bini to the Onitsha-Ibo until the Eastern Ibo. She got the Yoruba 'O' blood group gene frequency to be 0.7011. Watkin (1966) showed that no important anthropological divide exists between two populations showing no significant difference in the ABO blood group distribution. He also noted the influence of migrant groups on the inhabitants of an area and explained how the existence of a blood group associated with earlier human settlements could point to the survival of autochthonous people. Lister et al (1966) found the frequency for the 'O' blood group of the Bedouin Arabs of Soccotra to be 0.6667. El Hassan et al (1968) found the frequency of the 'O' blood group of the Beja of Sudan to be 0.53 even though they believed that the result showed a mixing of Negroid and East Mediterranean Caucausoid components, thus suggesting the need for more detailed work on East Mediterranean people and Africans South of the Sahara. Ikin et al (1969) obtained the 'O' blood group frequency of the Burmese to be 0.2892 with a genic frequency of 0.16667. Roberts et al (1972) obtained the genic frequency of the Sinhalese of Ceylon to be 0.123. Worlledge et al (1974) worked on 26,027 donor samples of the UNIVERSITY OF IBADAN LIBRARY 97 Yoruba to obtain an 'O' blood group percentage as 51.5 and genic frequency of 0.717. This value compared with those of some neighbouring language sub-families of the Yoruba (Table 7). Abdullahi (1976) obtained the 'O' blood group genic frequency of Arabs in Basrah to be 0.621. He noted how the effect of the genetic isolation of a group due to social and geographical barriers could inhibit gene exchange with other region's population. Mitchel and Sunderland (1978) showed how the effect of very large numbers of immigrant population in proportion to total population of the indegenous inhabitants of a territory, could be of considerable genetic influence on the ABO blood group frequencies, if these immigrants' frequencies reflect some dominance or dilution. Attai et al (1985) showed that the blood group percentage of a subgroup could be influenced by other boundary groups. Some of such groups have been shown by other workers to exhibit the stated ABO blood group percentiles and gene frequencies (Table 6). ABO Grouping Data of the Yoruba: Findings Research by earlier workers on the ABO blood grouping of the Yoruba have so far been largely based on the assumption that there was considerable biological homogeneity within the Yoruba language UNIVERSITY OF IBADAN LIBRARY 98 TABLE 6 VALUES OF ABO BLOOD GROUP DATA OF THE YORUBA After Garlick (1962); Hardy (1962) and Worlledge et al (1974). A AB O Percen- I 10-15 10-15 70-75 tile: (%) II 20.7 27.3 3.6 43.5 III 21.3 23.3 3.9 51.5 Gene Frequ- I - - - - encies II 0.1300 0.1687 - 0.7011 \ III 0.136 0.147 - 0.717 Key: I Garlick II Hardy III Worlledge Yoruba S u b -g ro u p s ( " I ” d ia le c t g ro u p ) 1800 1600 1400 1200 1000 - 800 600 - I /; 1 400 - H // i 200 * 1 ■: i 0 m *o ® D ° 1 cCS 5 t§ 3 CO D ® -O CO9 E 9< < .2, D I I* Y o ru b a S u b -g ro u p s ( " u " d ia le c t g ro u p ) Fig. 21: M ult ip le bar charts of ABO B lood Group d is t r ib u t io n in d ia le c t g ro up s . U Blood groups In samples Blood group in samplesNIVERSITY OF IBADAN LIBRARY 116 blood groups, respectively is the general trend within the Yoruba sub-groups considered in this study (Table 10). This is generally, similar to the trend obtained in the works of Hardy (1962) and that of Worlledge et al (1974). Percentiles of Blood Groups The values for blood group distribution for the 3000 samples considered for the Yoruba sub-groups (Table 10) were used to derive percentiles (Appendix 2) . These percentile values also followed the trend already noticed in the blood group distribution from highest to lowest, thus: 0,B, A to AB. In the Akoko sub-group for instance, the percentile values of blood groups in batch samples (replicates) were as follows: For blood group A: Batch I: 19.00; Batch II: 19.00; Batch III: 19.20; Batch IV: 19.00; Batch V: 18.80; and Batch VI: 19.00 (Appendix 6). For blood group B: Batch I: 24.00; Batch 11:23.80; Batch 111:23.60; Batch IV: 24.20; Batch V: 24.00; and Batch VI:23.80. For blood group AB: Batch I: 2.40; Batch II: 2.80; Batch III: 2.60; Batch IV:3.20; Batch V: 2.60; and Batch VI: 3.20. For blood group O: Batch I: 54.60; Batch II: 54.40; Batch III: 54.60; Batch IV: 53.60; Batch V: 54.60; and batch VI: 54.00. Each of these batch samples (replicates) values for the Akoko group samples of the four ABO blood groups highlighted above UNIVERSITY OF IBADAN LIBRARY 117 60 -| 50 ESI B 40 - M AB 30 - H O 20 - 10 - 0 Yoruba S u b -g ro u p s ( " I " d ia le c t g ro u p ) otn 60 - c oo 50 - w0> Cl 40 - VQ) O3 . 30 - i— o> 20 - ■o o mo 10 - ! I t 0 Xo DC xO XD D 5 n D t0n3 D E 03 2m. I < < a>CD -O UJ ® r D 03 cc >LU Yoruba S u b -g ro u p s ( " u " d ia le c t g ro u p ) Fig. 22: Multiple bar charts of ABO Blood Group Percentiles: in dialect groups UN Blood Groups' percentilesIVERSITY OF IBADAN LIBRARY 118 (Appendix 6) give percentile blood group values (cumulative) for the Akoko sub-group B: 23.9; Blood group A B : 2.8; and Blood group 0: 54.3. This as well, follows the styles of analysis of Hardy (1962) and Worlledge et al (1974). 4.5 Gene Frequencies of Blood Groups: The values of the blood group distribution obtained for the Yoruba sub-groups of the 3000 samples considered (Table 10) were used for the derivation of gene frequencies (Appendix 3). For instance, in the case of the Akoko sub-group (Appendix 7) , the following gene frequencies were obtained for the 500 batches of six samples sites. For Blood group A: Batch I: 0.02; Batch II: 0.02; Batch III: 0.03; Batch IV: 0.03; Batch IV 0.03; Batch V: 0.02; Batch VI: 0.03. For blood group B: Batch I: 0.07; Batch II: 0.07; Batch III: 0.07; Batch IV: 0.08; Batch V: )0.07; Batch VI: 0.08. For blood group AB: Batch I: 0.02; Batch II: 0.03; Batch III: 0.03; Batch IV: )0.03; Batch V: 0.03; Batch VI: 0.03. For Blood group 0: Batch I: 0.074; Batch II: 0.74; Batch III: 0.74; Batch IV: 0.73; Batch V: 0.74; Batch VI: 0.73. Each of these blood group gene frequency values for the batch samples (replicates) give cumulative gene frequencies for the Akoko sub-group (Fig.23 ) as follows: UNIVERSITY OF IBADAN LIBRARY 119 o c 0 .8 -i 3VO0>' - 0.6- v c« o» 0 0.4 - a O3 5) 0.2 - TOJO CD 0.0 ■ o <5 Yoruba s u b -g ro u p s ( " I " d ia le c t g ro u p ) ( " u " d ia le c t g ro up ) Fig. 23: Bar charts of ABO Blood Group gene frequencies: in dialect groups U Blood g roups ' gene frequenc iesNIVERSITY OF IBADAN LIBRARY 120 Blood Group A: 0.1157 Blood Group B: 0.1433 Blood Group AB: 0.028 Blood Group 0: 0.7369 The method used in calculating the gene frequency values compares with those of Race and Sanger (1968) and Boorman and Dodd (1970). It is also in accordance with the standards followed by Hardy (1962) and Worlledge et al (1974). Analysis of Variance fAnova) Results: Blood Group Percentiles; The batch sample records (replicates) of the blood group of the Yoruba sub-groups (Appendix 6) were subjected to Analysis of variance tests (Anova) in order to ascertain the degree of l significant differences of the blood group values (percentiles and gene frequencies) for the many Yoruba sub-groups. This test was also undertaken in order to establish the stratification (partition) if any, within these Yoruba sub-groups (Appendices 9 - 15) . For the blood group A (percentiles) results of the analysis of variance (Anova) tests (Appendix 8) , the F-ratio for the blood group (percentile) treatments of twenty-five (25) Yoruba sub-group is 334.68. The Blood Group A (percentiles) mean values of these sub-groups: UNIVERSITY OF IBADAN LIBRARY 121 750 -i «10 CL E ro w 500 c tO CL 3O o> 250 TO3o CQ _V0)J CL E ro to c tQo O3 . Dk_) ■Oo mo Y o rub a s u b -g ro u p s ( " u " d ia le c t g ro u p ) Fig 24 : Bar c h a r ts of B lood G roup-A in samples in d ia le c t g roups. UNIVERSITY OF IBADAN LIBRARY 122 (Owu, Awori, Igbomina, Ife, Oyo, Ibolo, Ilorin, Ibarapa, and Egba) in the range 22.50% to 23.10% varied significantly (df= 24; p>0.05) from the blood group A (percentiles) mean values of the other Yoruba sub-groups (Ilaje, Ijebu, Kabba, Ijumu, Remo, Yagba, Egbado, Bunu, Ikale, Ondo, Ekiti, Akoko, Owo, Ijesa, Eko and Akure) in the range 17.57% to 19.40%. This significance is confirmed by the Duncan multiple range test applied on the means of the Yoruba sub-groups (Appendix 8). The Duncan multiple range test showed clearly the partition between the first set of the Yoruba sub-groups: (Owu, Awori, Igbomina. Ife, Oyo, Ibolo, Ilorin, Ibarapa, and Egba) and the rest of these Yoruba sub-groups: (Ilaje, Ijebu, Kabba, Ijumu, Remo, Yagba, Egbado, Bunu, Ikale, Ondo, Ekiti, Akoko, Owo, Ijesa, Eko, and Akure). There were overlaps evident, with the Duncan grouping system, for blood group A (percentiles) mean values within each of the two sets of Yoruba sub-groups. For blood group B (percentiles) mean values results of the Analysis of variance (Anova) tests (Appendix 9), gave the F-ratio to be 5.67 for the treatments of the twenty-five (25) Yourba sub­ groups . There is significant difference (df=24: p>0.05) between the blood group B (percentiles) mean values in the range 22.87% to UNIVERSITY OF IBADAN LIBRARY 123 750 i oi Y o ru b a s u b -g ro u p s ( " I " d ia le c t g ro u p ) ( " u " d ia le c t g ro u p ) Fig 25 : Bar charts of B lood Group-B In samples In d ia lect g ro u p s . UNIVERSITY OF IBADAN LIBRARY 124 23.90% for the Yoruba sub-groups: Ibarapa, Ibolo, Egba, Owu, Egbado, Ife, Ilorin, Awori, Oyo, Igbomina, Remo, Eko, Ijebu, Ijesa, Ikale, Owo, Ekiti, Ilaje, Ijumu, Kabba, Yagba, Akure, Bunu, Ondo, and Akoko. Duncan multiple range test applied on the means of these blood group B (percentiles) values show that there is significant difference for these values of the twenty-five Yoruba sub-groups. There were overlaps evident within the Duncan grouping system. For the blood AB (percentiles) mean values, the results of the Analysis of variance (Anova) tests (Appendix 10) gave the F-ratio to be 4.00 for the treatments of the twenty-five (25) Yoruba sub­ groups . There is significant difference (df=24; p> 0.05) between the blood group (percentiles) mean values in the range 2.41% to 3.30% for the Yoruba sub-groups: Ibarapa, Ilorin, Owo, Awori, Igbomina, Oyo, Ibolo, Egbado, Ife, Bunu, Ekiti, Ondo, Akure, Ijumu, Owu, Egba, Eko, Akoko, Yagba, Kabba, Remo, Ijesa, Ikale and Ijebu. Duncan multiple range test carried out on the means of these blood group AB (percentiles) for the Yoruba sub-groups showed that there is significant difference. There were overlaps within the Duncan grouping system for the blood group AB (percentiles) of the mean values for the twenty-five UNIVERSITY OF IBADAN LIBRARY 125 Yoruba s u b - g r o u p s ( " I " d ia le c t g ro u p ) 100 90 i0n) 80 H CL E ra 70 in 60 c 50 -j in C3LO 40 -j k_ CT 30 ■a 20 oo m 10 0 o ® 3 o ~ 5? 3 CO 3 ©O 3 C 2W CO CO^ E<3 5 f © j C ®< < n lu 3 tr >8-* Yoruba s u b - g r o u p s ( "u " d ia le c t g ro u p ) Fig 26 : Bar charts of Blood G ro u p -A B In sam p les In d ia lect g ro u p s . UNIV Blood groups In samplesERSITY OF IBADAN LIBRARY 126 (25) Yoruba sub-groups. For the blood group 0 (percentiles) mean values, the results of the analysis of variance (Anova) tests (Appendix 11) gave the F- ratio to be 83.77 for the six (6) replicates (Appendix 6) of the twenty-five (25) Yoruba sub-groups. The blood groups 0 (percentiles) mean values in the range 51.30% to 51.80% for the first set of Yoruba sub-groups: (Egba, Oyo, Ilorin, Ibolo, Igbomina, Ife, Awori, Ibarapa, and Owu) vary significantly (df=24; p<0.05) from those in the range 54.20% to 55.33% for these Yoruba sub-groups: Akure, Akoko, Ijesa, Ondo, Ikale, Eko, Owo, Ekiti, Bunu, Yagba, Ijumu, Remo, Kabba, Ilaje, Ijebu, and Egbado. (see Fig. 31.) While there were no overlaps in the Duncan grouping for the blood group O (percentiles) mean values of the first set of Yoruba sub-groups in the range 51.30% to 51.80%, there were in the other set in the range of 54.20% to 55.83%. Analysis of Variance (Anova) Results: Blood Group Gene Frequencies: The batch sample records (replicate) of the blood groups (Appendix 7) of the twenty-five (25) Yoruba sub-groups were subjected to Analysis of Variance (Anova) tests to ascertain the degree of significant difference of the blood group gene UNIVERSITY OF IBADAN LIBRARY 127 1800 1600 1400 1200 1000 800 600 400 200 O © <3 c 5 \l 1 nOi L i o < jD 5o> Yoruba s u b - g r o u p s ( " I " d ia le c t g ro u p ) Yoruba s u b -g ro u p s ( " u " d ia le c t g ro u p ) Fig. 27: Bar charts of Blood G roup*0 sam ples: in d ialect groups. UN Blood groups in sample Blood groups in sampleIVERSITY OF IBADAN LIBRARY 128 frequencies. This test was also undertaken, using Duncan multiple range test, in order to ascertain the stratification (partition) if any, within the Yoruba sub-groups (Appendix 12). For the blood group A (gene frequencies), the analysis of Variance (Anova) results (Appendix 12) gave the F-ratio to be: 66.76 for six (6) replicates (Appendix 7) of twenty-five (25) Yoruba sub-groups. The blood group A (gene frequencies) mean values in the range 0.018 to 0.030 for the first set of Yoruba sub-groups: (Ijumu, Ilaje, Ondo, Yagba, Kabba, Ijebu, Egba, Remo, Bunu, Ekiti, Akoko, Akure, Owo, Ikale, Ijesa and Eko) vary significantly (df=24; p<0.05) from those ini the range 0.048 to 0.057 for the other Yoruba sub-groups: (Igbomina, Ibolo, Awori, Oyo, Ibarapa, Ilorin, Ife, Owu and Egba). The Duncan multiple range test was applied on the means of these blood group A (gene frequencies) for the twenty-five (25) Yoruba sub-groups (Appendix 12) , and showed that there is a significant difference between the blood group A (gene frequencies) in the range 0.018 to 0.030 and 0.048 to 0.057 for the first and second sets of the Yoruba sub-groups respectively. There is also a partition of these sets of Yoruba sub-groups in the Duncan multiple UNIVERSITY OF IBADAN LIBRARY 129 vo>> co ku<_D CL Q. O3 i_ CT ■Ooo CD Yoruba s u b - g r o u p s ( " I " d ia le c t g ro u p ) Yoruba s u b -g ro u p s ( " u " d ia le c t g ro u p ) St Fig 28 : Bar charts ot B lood G roup-A (P e rcen t i les ) In d ia lec t g roups . UNBIlood groups percentilesVERSITY OF IBADAN LIBRARY 130 range grouping which also reflected overlaps within each of these sets of the Yoruba sub-groups. For the blood group B (gene frequencies), the Analysis of Variance (Anova) results (Appendix 13) gave the F-ratio to be 30.93 for the six (6) replicates of the twenty-five (25) Yoruba sub­ groups . The blood groups B (gene frequencies) mean values in the range 0.050 to 0.058 for the first set of the Yoruba sub-groups: (Ibolo, Ibarapa, Ife, Egba, Oyo, Ilorin, Owu, Awori, and Igbomina) vary significantly from those in the range 0.067 to 0.080 for other set of the Yoruba sub-groups: (Owo, Akure, Eko, Ondo, Ijesa, Egbado, Remo, Ijumu, Ekiti, Ikale, Yagba, Bunu, Akoko, Kabba, Ijebu and Ilaje) . The Duncan multiple range test was applied on the means of these blood group B (gene frequencies) for the twenty-five (25) Yoruba sub-groups (Appendix 13). This showed that there is a significant difference (df=24; p<0.05) between the blood group B (gene frequencies) mean values in the range 0.050 to 0.058 for the first set of the Yoruba sub-groups: (Ibolo, Ibarapa,Ife, Egba, Oyo, Ilorin, Owu, Awori and Igbomina) and those in the range 0.067 to 0.080 for the second set of the Yoruba sub-groups: (Owo, Akure, Eko, Ondo, Ijesa, Egbado, Remo, Ijumu, Ekiti, Ikale, Yagba, Bunu, UNIVERSITY OF IBADAN LIBRARY 131 Yoruba s u b -g ro u p s ( " I " d ia le c t g ro u p ) 30 i 20 - 10 - oO ®3 DC o <53 D ts DjC >- 5 ■Q *5 H E ns 2 i 2 :< < _rQr» LU 5 i ■ ? -UJ Yoruba s u b -g ro u p s ( " u " d ia le c t g ro u p ) Fig 29 Bar ch a r ts of Blood Group-B (P e rcen t i les ) in d ia le c t g ro up s . UN B lood g ro u p s p e rc e n tile s B lo o d g ro u p s p e rc e n tile sIVERSITY OF IBADAN LIBRARY 132 Akoko, Kabba, Ijebu and Ilaje). There is also significant difference and partition of these two sets of Yoruba sub-groups through the Duncan multiple range test applied which reflected overlaps in the Duncan grouping (Appendix 13). For the Blood group AB (gene frequencies), the results of the analysis of variance (Anova) tests gave the F-ratio to be 2.32 for the six (6) replicates of the twenty-five (25) Yoruba sub-groups (Appendix 7). There is no significant difference (df=24; p>0.05) within the blood group AB (gene frequencies) mean values (Appendix 14) in the range 0.020 to 0.033 for the twenty-five (25) Yourba sub-groups. The Duncan multiple range test applied on the means of the blood group AB (gene frequencies) values for the twenty-five (25) Yoruba sub-groups also showed no significant difference. There was no partition even though, there were overlaps within the Duncan grouping for the twenty-five (25) Yoruba sub-groups (Appendix 14) . For the blood group O (gene frequencies), the results of the Analysis of variance (Anova) test gave the F-ratio to be 38.01 for the six (6) replicates (Appendix 7) of the twenty-five (25) Yoruba sub-groups (Appendix 15). There is a significant difference (df=24; p<0.05) between the UNIVERSITY OF IBADAN LIBRARY 4.5 133 4.5 3 .0 - 1.5 - ; 0.0 • o ®k— 3 —X C | 9 ^ 3 SCT3 ££ o Oo 3 3 12 <0a> Ee. -D UJ 3^ j?j CD ns O < if f * ° =--f Y o rub a s u b -g ro u p s ( "u " d ia le c t g ro u p ) Fig 30 Bar charts of B lood G roup-AB (P e rcen ti les ) In d ia lec t g roups. UN B lood g ro u p p e rc e n tile sIVERSITY OF IBADAN LIBRARY 134 blood group 0 (gene frequencies) mean values (Appendix 15) in the range 0.717 to 0.720 for the first set of Yoruba sub-groups: (Egba, Ilorin, Ibarapa, Oyo, Owu, Ibolo, Igbomina, Awori, and Ife) and those mean values in the range 0.738 to 0747 for the other set of Yoruba sub-groups (Akoko, Akure, Owo, Ikale, Ondo, Ijesa, Ekiti, Bunu, Eko, Yagba, Ijumu, Remo, Egbado, Ilaje, Ijebu and Kabba). The Duncan multiple range test applied on the means of these blood group O (gene frequencies) values reflect that there is a significant difference (df=24; p<0.05) between those in the range 0.717 to 0.720 belonging to the first set of Yoruba sub-groups: (Egba, Ilorin, Ibarapa, Oyo, Owu, Ibolo, Igbomina, Awori and Ife) and the others in the range 0.738 to 0.747 for the second set of Yoruba sub-groups: (Akoko, Akure, Owo, Ikale, Ondo, Ijesa, Ekiti, Bunu, Eko, Yagba, Ijumu, Remo, Egbado, Ilaje, Ijebu and Kabba). This Duncan multiple range test also established a partition between these two sets of Yoruba sub-groups in its grouping system. There were overlaps within Yoruba sub-groups with blood group O (gene frequencies) mean values in the range of 0.738 to 0.747 while there was none in the other set of Yoruba sub-groups with blood group 0 (gene frequencies) mean values in the range 0.717 to 0.720. UNIVERSITY OF IBADAN LIBRARY 135 60 - i at Yoruba s u b -g ro u p s ( " I " d ia le c t g ro u p ) Yoruba s u b - g r o u p s ( " u " d ia le c t g ro u p ) Fig. 31: Bar charts of Blood G roup-0 (percentiles) in dialect groups. UN Blood group percentiles Blood 9rouP PercentilesIVERSITY OF IBADAN LIBRARY 136 Chi-square (Matrix) Values for the Significance of Difference in the ABO Blood Group Distribution in the Yoruba Sub-groups: The blood group distribution values of the Yoruba sub-groups (Table 11) was subjected to Chi-square (X2) matrix analysis. This was calculated (Appendix 4) after the example of Worlledge et al (1974) . The results of the Chi-square matrix analysis of the twenty- five (25) Yoruba sub-groups considered in this study showed that there s a significant difference (df=3) between the X2 values of second set of Yoruba sub-groups: (Akoko, Akure, Bunu, Egbado, Ekiti, Eko, Ijebu, Ijesa, Ijumu, Ikale, Ilaje, Kabba, Ondo, Owo, Remo and Yagba) and the X2 values of the first set of the Yoruba sub-groups: (Awori, Egba, Ibarapa, Ibolo, Ife, Igbomina, Ilorin, Owu and Oyo). Any of the X2 values in this analysis are significant if it is equal to or greater than 7.815 or 7.82 at the 0.05 (or 5%) level of significance or equal to or greater than 11.341 or 11.34 at the 0.01 (or 1%) level of significance (Table 11) as derived from standard statistical tables at 3 degrees of freedom (Clarke, G.M., 1980; Parker, R.E, 1979; Bailey, N.T.J., 1959; Walpole, R.E., 1974) . UNIVERSITY OF IBADAN LIBRARY / Blood group gene frequencies O O O O Blood group gene frequencies Awori Egba Ibarapa Ibolo oCr Ife to o TcJ Igbomina Morin Owu Oyo UNIVERSITY OF IBADAN LIBRARY 0.14 d ia le c t g ro up ) 0.14 Yoruba s u b - g r o u p s ( " u " d ia le c t g ro u p ) Fig 32 : Bar charts of Blood G rou p -A (Gene F requencies) In d ia lect g roup . 138 For instance, when compared to Akoko (Table 11), the X2 values for these Yoruba sub-groups are not significantly different (df=3): Akure, 0.21; Bunu, 0.34; Egbado, 1.53; Ekiti, 0.23; Eko, 0.39; Ijebu, 2.68; Ijesa, 0.38; Ijumu, 0.90; Ikale, 0.68; Ilaje, 3.39; Kabba, 1.31; Ondo, 0.11; Owo, 0.50; Remo, 1.31; and Yagba, 0.52. The values of X2 these other Yoruba sub-groups when compared to Akoko (Table 11) are significantly different (df=3): Awori, 11.89; Egba, 15.23; Ibarapa, 14.22; Ibolo, 13.82; Ife, 13.17; Igbomina, 11.95; Ilorin, 14.45; Owu, 11.20; and Oyo 13.22. The trend of partition between these two sets of Yoruba sub­ groups is reflected throughout the chi-square matrix analysis (Table 11). Bar Charts of the Blood Group Values of the Yoruba Sub-groups: The blood group data (Table 10) of the Yoruba sub-group considered in this study were also illustrated at every stage through Bar Charts (Figures 20 - 35) . Comparative values for the four blood groups of the Yoruba sub-groups and two emerging dialect groups are thus derived, especially from the values of the Figures 36 - 39. For the blood group A, the (average) percentile values for the first set of Yoruba sub-groups (Awori, Egba, Ibarapa, Ibolo, Ife, UNIVERSITY OF IBADAN LIBRARY 139 < < $ Y o rub a s u b -g ro u p s ( " u " d ia le c t g ro u p ) Fig 33 : Bar charts of B lood Group-B (Gene Frequencies) In d ia lec t g roup . UNBlood group gene frequenciesIVERSITY OF IBADAN LIBRARY 140 Igbomina, Ilorin, Owu, and Oyo) is 22.80%. The blood group B percentile (average) value for this first set of Yoruba sub-groups is 23.23%. The blood group AB (average) percentile value for this first set of Yoruba sub-groups is 2.5%. The blood group 0 (average) percentile value of the first set of Yoruba sub-groups is 51.6%. The blood group (average) frequency values for this first set of Yoruba sub-groups is as follows: Blood group A: 0.05; Blood group B: 0.06; Blood group AB: 0.026; and Blood group O: 0.718. For the other set of Yoruba sub-groups (Akoko, Akure, Bunu, Egbado, Ekiti, Eko, Ijebu, Ijesa, Ijumu, Ikale, Ilaje, Kabba, Ondo, Owo, Remo and Yagba) the Blood group percentiles (average) values are as follows: Blood group A: 18.64%; Blood group B: 23.52%; Blood group AB: 2.84%; and Blood group 0: 55.0%. Similarly, the gene frequencies (average) values for this latter set of Yoruba sub-groups are : Blood group A: 0.823; Blood group B: 0.072; Blood group AB: 0.029; and Blood group O: 0.742. UNIVERSITY OF IBADAN LIBRARY Blood group gene frequencies Blood group gene frequencies p o p UNIVERSITY OF IBA woDAN LIBRARY 0.04 d ia le c t g ro u p s ) Y o ru b a 3 u b -g ro u p 3 ( " u " d ia le c t groups)? Fig 34 : Bar charts of B lood G roup-AB (Gene Frequencies) In d ia lec t g roups. CHAPTER FIVE DISCUSSION OF THE RESULTS OF THE ABO BLOOD GROUPING OF YORUBA SUB-GROUPS Dominance of Blood Group 'O': The results of this study show that the ABO blood group samples of the Yoruba language sub-family has the presence of more blood group ' O ' individuals than others. This result is similar to the findings of some earlier workers: Garlick (1962); Hardy (1962); and Worlledge et al (1974). This result is seen as shown in some of the sub-group values thus: (Akoko: A = 57 0; B = 717; AB = 84; 0 = 1629); and (Akure: A =582; B = 711; AB = 81 0 = 1626 (Table 10). Two Yoruba Dialect Groups: The blood group values obtained for the different Yoruba sub­ groups, especially in blood group 'O', agree in some cases with the values of some earlier workers such as: Hardy (1962) and Worlledge et al (1974), while in some other cases, the values are quite different. There is a new range of blood group 'O' values. The Yoruba sub-groups that have their blood group values similar to those of some workers (Hardy: 1962; Worlledge et al: 1974) include: Awori, Egba, Ibarapa, Ibolo, Ife, Igbomina, Ilorin, Owu and Oyo. The blood group values of these Yoruba sub-groupps (Table 10) are 142 UNIVERSITY OF IBADAN LIBRARY 143 Y o ru b a s u b -g ro u p s ( " I " d ia le c t g ro u p s ) Y o ru b a s u b -g ro u p s ( " u " d ia le c t g ro u p ) Fig. 35: Bar charts of B lood G roup-0 (gene frequencies) in dialect groups. UNI Gene frequencies blood group Gene frequencies blood groupVERSITY OF IBADAN LIBRARY 144 not significantly different (Appendices 8 - 15) from the values earlier obtained by Hardy (1962) and Worlledge et a_l (1974). The other Yoruba sub-groups that have blood group values (Table 10), Appendices 8 - 15) significantly higher than those obtained by some earlier workers (Hardy: 1962; Worlledge et al: 1974) include: Akoko, Akure, Bunu, Egbado, Ekiti, Eko, Ijebu, Ijesa, Ijumu, Ikale, Ilaje, Kabba, Ondo, Owo, Remo and Yagba. Bilolooical Partition: This higher range of blood group 'O' values in the latter Yoruba sub-groups seems to signify that these sub-groups are biologically (genetically) different from the former sub-groups who have blood group 'O' values similar to those obtained by some earlier workers (Hardy: 1962; Worlledge et ad: 1974). This thus suggests that there are two groups within the Yoruba language sub­ family. The two ranges of blood group 'O' values obtained for the Yoruba sub-groups are the result of more representative sampling through the 25 treatments (Yoruba sub-groups) and 6 replicates per sub-group used as criteria for the blood group study of the Yoruba as not hitherto done. Worlledge et al (1974) sampled only in Ibadan and this was at sub-family level as against the more complete and more careful study of Yoruba sub-groups in this work. UNIVERSITY OF IBADAN LIBRARY 145 Correlation of Biological and Linguistic Evidence: The two groups of the Yoruba sub-groups set apart through their blood group values, especially the blood group 'O', significantly enough, would appear to coincide with the two dialect areas: -i, and -u of Yorubaland (Fig. 12) proposed by Oduyoye (1972). This thus, shows that there is a biological divide within the Yoruba language sub-family obtained through the blood group values (Table 10); which coincides with the dialect areas ("i" and "u") proposed by Oduyoye (1972) based on linguistic distinction. There thus seems to be remarkable correlation between the biological divide and the cultural (language) grouping. This constitutes a very significant illustration of a possible link between culture and biology as the coincidence of the two groupings, based on two different parameters, is likely to be more than fortuitous. Anthropological Divide of the Yoruba Language Sub-Family: These two dialect groups of the Yoruba language sub-family are located as follows: "i-" dialect group (North-West and part of South-West Yorubaland). "u-" dialect group (North-East, South, East and part of South- West Yorubaland). (see Fig. 12) UNIVERSITY OF IBADAN LIBRARY Com parative average Gene frequencies of C om parative average P e rcen t i les of B lood group-A (In d ia lect groups) Blood group-A (In d ia lect g roups)UNIVERSITY OF IBADAN LIBRARY Fig. 36 : Com parative average p e rcen t i les and frequencies of B lood Group-A In d ia lect groups 147 The coincidence of biological, linguistic and territorial (geographical) data thus highlighted confirms the proposal of Oduyove (1972). There would seem therefore to be a definite anthropological divide of the Yoruba language sub-family into two dialect groups: "i" and "u". (see Fig. 48,) Negroid Marker: Blood Group 'B': The results of this study show that there is a greater number of individuals in the blood group 'B' than in blood group 'A' (Table 10). It confirms that the people who today belong to the Yoruba language sub-family are Negroid, since high blood group 'B' value is a feature of Negroid populations. (Hardy 1962). This thus agrees with the findings of some earlier workers. Hardy (1962) and Worlledge et al (1974). The significance of the Negroid character of the Yoruba is that they are not in the main, migrants from the East where more mediterranean and less Negroid peoples abound. There are more individuals within the blood group 'B' within the "u" dialect group than within the "i" dialect group (Fig. 25; Appendix 5). This thus, confirms that the "u" dialect group which has the higher value of blood group 'B' individuals, is more Negroid than the "i" dialect group; the latter is of lesser antiquity than the "u" dialect group. The West to East diminution of blood group 'B' values from the Yoruba to the Bini (or Edo) , UNIVERSITY OF IBADAN LIBRARY I Comparative average Percentiles of Comparative average Gene frequencies of Blood group-B (In dialect groups) Blood group-B (in dialect groups) Oo O JL o (Table 10) in the "i" dialect Yoruba sub-groups occuring alongside the lower values of the blood groups 'B' and 'O'. This possibly implies more marked dilution and intrusion influences within the Yoruba sub-groups in the "i" dialect group as well as lower degrees of negritude based on the lower blood group 'B' values as well as lower degrees of antiquity as their lower blood group 'O' values shown. These higher values of blood group 'A' within the "i" dialect Yoruba sub-groups is in this decreasing order: Egba, Ilorin, Ibarapa, Ibolo, Ife, Oyo, Awori, Igbomina, and Owu. Within the "u" dialect Yoruba sub-groups, there are generally lower blood group "A" values (Table 10) occuring alongside higher values of blood groups 'B ' and 'O' suggesting that there were less marked dilution and intrusion influences in the Yoruba sub-groups of this dialect group. The higher blood groups 'B ' and 'O' values as well imply that there are higher degrees of negritude (often associated with high blood group 'B' gene frequencies) and antiquity (shown by higher 'O' blood group values) within the 'u' dialect Yoruba sub­ groups in this decreasing order: Akure, Eko, Ijesa, Owo, Akoko, Ekiti, Ondo, Ikale, Bunu, Egbado, Yagba, Remo, Ijumu, Kabba, Ijebu and Ilaje. UNIVERSITY OF IBADAN LIBRARY 153 Influences on Boundary Yoruba sub-groups: The results of this study show that there has been some influence on the boundary sub-groups of the two Yoruba dialect groups. The tendency for higher numbers in the blood group 'O' values is evident in such boundary Yoruba sub-groups as : Ibarapa (51.9%); Owu (51.8%); Awori (51.7%); Ife (51.6%); Igbomina (51.6%). This tendency is due possibly to the influences of the "u" dialect Yoruba sub-groups on these stated "i" dialect sub-groups with blood values a bit higher than the value of 51.5% obtained for Yoruba by Worlledge et al (1974) and shown comparatively by Ilorin (51.533%); Oyo (51.5%); and Egba (51.3%). The possibility for the antiquity or remoteness of time of settlement of these "i" dialect Yoruba is likely to be thus: (in order of greater antiquity to lesser): Ibarapa, Owu, Awori, Ife, Igbomina, Ilorin, Oyo and Egba (Table 10) . Thus, it can be said that the Ekiti and Yagba influenced the Igbomina; the Ijesa must have had some influence on the Owu and Ife, while the Ijebu must have influenced the Owu. The Awori must been influenced by the Eko and the Egbado while the Egba would have been influenced by the Egbado and Remo. The Egbado influence on the Ibarapa is as well very likely as a spill-over of boundary influences (Fig. 48). Based on the blood group 'O' values of the "u" diaclect Yoruba, the possibility of an order of antiquity based UNIVERSITY OF IBADAN LIBRARY 154 D i a l e c t g r o u p s 1.0 -i 0.9 0.8 - 0 . 7 4 0 .7 1 0.7 - 0.6 - 0.5 - 0.4 - 0.3 ■ 0.2 0.1 H 0.0 *• j n D i a l e c t g r o u p s Fig. 39: C o m p a r a t i v e a v e r a g e p e r c e n t i l e s a n d g e n e f r e q u e n c i e s of Blood G r o u p - 0 in d ia lect groups . UN C a m p a r a t l v e G e n e f r e q u e n c i e s o f C a m p a r a t i v e a v e r a g e p e r c e n t i l e s o fI B lo o d G r o u p - 0 ( In d i a l e c t g r o u p s ) B l o o d G r o u p - O ( In d ia le c t g r o u p s )VERSITY OF IBADAN LIBRARY 155 on this results of this study is likely to be: Egbado, Ijebu, Ilaje, Kabba, Remo, Ijumu, Yagba, Ekiti, Owo, Ikale, Ondo, Eko, Bunu, Ijesa, Akoko and Akure. Higher Tendency for the Occurrence of peptic ulcer: From the results of this study, there is a higher number of blood group 'O' individuals within the "u" dialect group than the "i" dialect group. Since peptic ulcer is more statistically associated with blood group 'O' individuals (Bell et aj,, 1972) which are higher in number in the "u" dialect group, there is therefore, the tendency for a greater occurrence of ulcer within the "u" dialect group than in the "i" dialect group. Genetic variation within the Yoruba Dialect Groups: The results of this study show greater genetic variation (existence of more sub-groups and smaller units) in the "u" dialect group than in the "i" dialect group. This implies greater antiquity of the "u" dialect group; a feature that is the result of internal wandering or interbreeding that has promoted such recombinations, as Hiernaux (1974) put it. The "u" dialect has 16 Yoruba sub-groups as follows: Akoko; Akure (made up of Isikan, Isolo, Igiso, Eyinke and Oritagun sub-units); Bunu. Egbado (made up of Anago, Ketu, Sabe, Popo, Idassa sub-units mainly); Ekiti (including aboriginal Ilesun sub-unit); Eko (made up of Awori, Edo, UNIVERSITY OF IBADAN LIBRARY Fig- 40: Blood group map of Yoruba sub-groups : Gene -A UNIVERSITY OF IBADAN LIBRARY 157 Egbado, Ijebu, Mahin sub-units mainly); Iiebu (made up of Idoko, Idokunnusi and Eredo sub-units) ; Iiesa (made up of Ilowa, Ilemure, Hare, and Ilaye sub-units) ; Iiumu (made up of Gbede, Ayere, Ogidi and Ikiri sub-units) ; Ikale; Ilaie (made up of Ugbo, and Mahin sub­ units) ; Kabba (including the Oworo sub-unit); Ondo (made up of the Idoko and Ifore sub-units); Owo (including the Efene and some Ifore sub-units); Remo (made up of Offin, and Makun sub-units); and Yaqba. This is evidence of considerable genetic variation within the "u" dialect group. On the other hand, the "i" dialect group has only 9 sub-groups and follows: Awori; Egba (made up of Ake, Oke-Ona, Owu and Gbagura sub-units); Ibarapa; Ibolo; Ife; Iqbomina; Ilorin; Owu; and Oyo. There is thus, greater genetic variation which is a direct result of greater antiquity within the "u" dialect group than in the "i" dialect group. This further goes to support the contention that the "u" dialect group was possibly the autochthonous population in today's Yorubaland, which the "i" dialect group met on their later arrival there. Chi-Square Matrix Analysis: The Chi-square matrix results (after the example of Worlledge et al, 1974) meant to represent the significance of differences in UNIVERSITY OF IBADAN LIBRARY 158 Fig. 41". Blood group map of Yoruba sub-groups: Gene-B UNIVERSITY OF IBADAN LIBRARY 159 the ABO blood group distribution of the 25 Yoruba sub-groups considered in this study shows the separation of the latter (Yoruba sub-groups) into two groups which coincide with the "i" and "u" dialect groups earlier identified. As in Table 11, the following Yoruba sub-groups had values that were significantly different (statistically); the x2 values obtained starting from the first line (values are significant at 1% level when x2 is equal or greater than 11.34; they are significant at 5% level when x2 is equal or greater than 7,815) . Awori (significant at 1% level; with a value of 11.89); Egba (significant at 1% level, with a value of 15.23); Ibarapa (significant at 1% level, with a value of 13.82); Ife (significant at 1% level, with a value of 13.17); Iqbomina (significant at 1% level, with a value of 14.95); Ilonn (significant at 1% level, a value of 11.20); Ovo (significant at 1% level, with a value of 13.22). These are sub-groups of the "i" dialect group. The other Yoruba sub-groups whose x2 values are not significantly (statistically) different (as in Table 11) include: Akoko (with value of 0). Akure (with value of 0.21). Bunu (with value of 0.34). Egbado (with value of 1.53). UNIVERSITY OF IBADAN LIBRARY 160 2 - 2 .5 °/o 2. 6 - 3.0 7. I t s e k i r i NUrhobo 5 ° 30_ 3.1 - 3 • 5 % \ ' /\ J * / y - l s o k o - ^ E a s t e r n x J E 5 A : Su b G r o u p r 'TJrhobo)— M a j o r Tow n / C i ty Westernf\ • 5° — i n t e r n a t i o n a l B o u n d a r y : Y o r u b a land B o u n d a r y _ * E G U N •. Non Y o r u b a 4° 30 — 0L £0 _50L_ 75 —1I00 Km _ L _ __ L. Fig. U2 ■ Blood group map of Yoruba sub-groups: Gene-AB UNIVERSITY OF IBADAN LIBRARY 161 Ekiti (with value of 0.73) . Eko (with value of 0.39) . Iiebu (with value of 2.68). Iiesa (with value of 0.38). Iiumu (with value of 0.90). Ilaie (with value of 3.39). Ikale (with value of 0.68) . Kabba (with value of 1.31). Ondo (with value of 0.11). Owo (with value of 0.60). Remo (with value of 1.31). Yaqba (with value of 0.52). These are sub-groups of the "u" dialect group. The chi- square matrix analysis of the results of this study (Table 11) prepared after the example of Worlledge et al (1974) shows that there are two statistically distinct groups within the 25 Yoruba sub-groups considered. These two groups derived statistically coincide with the "i" and "u" dialect groups earlier proposed by Oduyoye (1972) based on linguistic distinction. Partition Into Two Dialect Groups: The 25 Yoruba sub-groups considered in this study and whose ABO blood distribution values were subjected to Chi-square UNIVERSITY OF IBADAN LIBRARY 162 9°- 8° 30 Akufupa 8° Ngbirra IJUMU 7o30' A, .'*■ " ) 7o • A* K• u• R‘ \\ > V'nWwj°n. “• If On tw „a n_ \ Etsa ko t ' ■ e / 1 X, */ \I Ishan * . < \ _ ( EDO) Bight of Benin /b lA* g bor/i A-s aba /Ea£tern\ / ■' 6°“ 5 1 - 5 2 °lo ^ y ' (^*W estern'^ 1 Aboh \ 54 - 55 °lo Itsek iri \U\ rhobo_ _‘y - AJ > " \ 5° 30- 55.1 - 5 6s/. — S( _Jg g-s t e r n \ I J E S A S u b G r o u p fyUr-hoboy M a j o r Town / C i t y 5°-Western e .. I n t e r n a t i o n a l B o u n d a ry •jaw y \ ) __ Y o r u b a la n d B o u n d a r y N o n Y o r u b a 30-* E G U N 75 1_l00Km UNIVERSITY OF IBADAN LIBRARY 163 (statistical) analysis (Table 11) show definite partition along the two dialect groups as follows (based on consistent and continuous significant differences in x2 values throughout the Table): "i" Dialect Group "u" Dialect Group Awori Akoko Egba Akure Ibarapa Bunu Ibolo Egbado Ife Ekiti Igbomina Eko Ife I jebu Owu I jumu Oyo I jesa Ikale Ila je Kabba Ondo Owo Remo Yagba UNIVERSITY OF IBADAN LIBRARY 164 Fig. 4 4 : Blood group map of Yoruba dialect groups G en e-A UNIVERSITY OF IBADAN LIBRARY 165 Varying Values of Significant Differences: The values of the significant differences of the 25 Yoruba sub-groups considered in this study (Table 10) vary from each pair of sub-groups considered. For instance, thesse sub-groups in the two different dialect groups have different x2 values Table 11 depending on the pair under comparison thus: "u" Dialect Group '*i*' Dialect Group x2 Values Akoko Awori 11.89 Akure Awori 9.37 Bunu Awori 14.10 Egbado Awori 16.63 These variations support the fact that the Yoruba sub-groups have varying degrees of heterogeneity and possibly admixtures within the 25 sub-groups considered in this study. Order of sub-groups based on x2 values: There are variations in the x2 values of significant differences within the 25 Yoruba sub-groups (Table 11) analysed. Such variations which can afford some ordering of these sub-groups is as well a measure of the extent of distinction of such sub­ groups from others within the same dialect group ("i" or "u") and UNIVERSITY OF IBADAN LIBRARY 166 0 -u 23 • 52 - 23 . 23 5 ° 30 - 1 J E S A Sub G r o u p • M a j o r T o w n / C i t y -- . --- . : I n t e r n a t i o n a l B o u n d a r y . Y o r u b a l a n d B o u n d a r y E G U N : Non Y o r u b a