Genetical Variation in Selected Populations in the Isle of Man and Neighbouring Areas
Total Page：16
File Type：pdf, Size：1020Kb
Durham E-Theses Genetical variation in selected populations in the isle of man and neighbouring areas Mitchell, Robert John How to cite: Mitchell, Robert John (1974) Genetical variation in selected populations in the isle of man and neighbouring areas, Durham theses, Durham University. Available at Durham E-Theses Online: http://etheses.dur.ac.uk/8171/ Use policy The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that: • a full bibliographic reference is made to the original source • a link is made to the metadata record in Durham E-Theses • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders. Please consult the full Durham E-Theses policy for further details. Academic Support Oce, Durham University, University Oce, Old Elvet, Durham DH1 3HP e-mail: [email protected] Tel: +44 0191 334 6107 http://etheses.dur.ac.uk 2 ABSTRACT This study reports upon the investigation of a number of genetic polymorphisms in indigenous population samples of three regions of the British Isles: the Isle of Man, Cumbria and South West Scotland. Sample selection proved to be important because differences were found in the similarly selected indi• genous Manx population - between donors and non-donors. In addition to a study of phenotype distributions and gene frequencies in the three selected populations, a regional analysis of the Manx data, though on a limited level, was effected. Though great difficulties were encountered obtaining indigenous samples, comparisons were performed between the Manx and population samples from selected regions of the mainland of the British Isles as well as certain north-west European popula• tions. Possible explanations of the differences observed between the Manx and surrounding populations were proposed, but it was also suggested that an analysis of the demographic data would be most informative. GENETICAL VARIATION IN SELECTED POPULATIONS IN THE ISLE OF MAN AND NEIGHBOURING AREAS. BY ROBERT JOHN MITCHELL A THESIS SUBMITTED FOR THE DEGREE OF DOCTOR OF PHILOSOPHY DEPARTMENT OF ANTHROPOLOGY UNIVERSITY OF DURHAM « 2 OCT 1974 ) ^L/BRARY CONTENTS Page INTRODUCTION i - iii CHAPTER ONE: The Isle of Man - Physical and Human Background 1 a) Physical Background 2 b) Human Background 10 1) Prehistory and History 10 Place Names 22 Personal Names (Surnames) 25 2) Population 33 Structure of the Manx Population 39 3) Economic Conditions 47 History of Economic Development 47 Present Day Economic Conditions 49 CHAPTER TWO: Physical Anthropological Studies in the Isle of Man. 52 a) Previous Studies 52 b) The present Survey 57 i) Scope and Aims t 57 ii) Materials and Methods 62 Field Methods 72 Laboratory Methods 80 Blood Group Antigens 80 Serum Proteins 97 Red Cell Isoenzymes 103 Statistical Methods 124 CHAPTER THREE: Analysis of Data Collected in the Present Survey. 128 I Serological Variability 128 a) Blood group antigens 128 b) Serum proteins 162 c) Red blood cell isoenzymes 164 II Non-Serological Variability 170 Conclusion 173 CHAPTER FOUR: Isle of Man - Regional Analysis 176 Introduction 176 Regional Divisions of the Island employed in previous anthropological studies 179 Regional divisions of the Island used in the present study 180 A) Serological Traits 185 1) Blood Group Antigens 185 2) Serum Proteins 197 3) Red Blood Cell Isoenzymes 198 B) Non-Serological Variability 201 Conclusions 203 CHAPTER FIVE: Comparison of the data collected in the present study with material from selected British,Irish,and European populations 205 1. Serological Traits 205 a) Blood Group Antigens 205 b) Serum Proteins 231 c) Red Blood cell Isoenzymes 236 2. Non-Serological Traits 245 Conclusion 255 CHAPTER SIX: Conclusion 261 ACKNOWLEDGEMENTS 270 REFERENCES 272 TABLES following 308 APPENDIX 1 28-31 APPENDICES 2-8 following 308 List of Figures Fig. 1 Isle of Man - Position in the Irish Sea Fig. 2 Isle of Man - Relief Fig. 3 Isle of Man - Generalised Geology Fig. 4 Isle of Man - Position in Relation to the Western Seaways Fig. 5 Isle of Man - Distribution of Neolithic Finds Fig. 6 Isle of Man - Distribution of Bronze Age Finds Fig. 7 Isle of Man - Distribution of Early Christian Period Remains Fig. 8 Isle of Man - The Kingdom of Man and the Isles Fig. 9 Isle of Man - Celtic and Scandinavian Place-names Fig. 10 Isle of Man - Population 1726-1971 and Intercensal Variations 1821-1971 Fig. 11 Isle of Man - 1851 A Population Watershed Fig. 12 Isle of Man - Birth and Death Statistics Fig. 13 Isle of Man - Population 1931-1971 Civil Parishes and Four Towns Fig. 14 Isle of Man - Population by Country of Birth 1951 and 1961 Fig. 15 Isle of Man - Sex Ratios 1821, 1851, 1931 and 1966 Fig. 16 Isle of Man - Civil Parishes and Four Town Districts - Population Distribution according to sex 1966 and 1971 Fig. 17 Isle of Man - Distribution of Population according to Selected Age Groupings 1966 and 1971 Fig. 18 Isle of Man - Population Change 1821 - 1966 Fig. 19 Isle of Man - Annual Number of Residents and Increase or Decrease Fig. 20 Isle of Man - Age and Sex structure of new residents 1958-1971 Fig. 21 Isle of Man - Destination of Immigrants 1958-1971 Fig. 22 Isle of Man - Selected Occupations 1861-1966 Fig. 23 Percentage Distribution of Dark and Fair Colouring in the Isle of Man Fig. 24 Final Samples - Numbers tested in each sample for each genetic factor Fig. 25 Isle of Man - Administrative Divisions (Pre -1796) - Also showing Division into Northside and Southside. INTRODUCTION Anthropology is essentially the study of the human species, the comparative study of man as a physical and cultural being. The physical anthropologist studies man's physical characters, their origin, evolution and present state of development. (Montagu 1960) Striking differences may be present in populations with respect to physical characters such as skin and hair colour, stature and hair form. Accordingly, physical anthropologists have long been interested in the description, comparison and classification of the groups of mankind. For these purposes they once used the measurement and description of various external physical character• istics of the body, such as height, weight, cephalic index and hair form and colour. Though populations could be described on the basis of such traits, assessing a group's exact genetic relationship was exceedingly difficult. First, methodological problems, such as the errors involved in taking body measurements, or the degree of subjectivity involved in classifying hair form and eye colour for example, introduce a certain amount of bias into the data on the populations to be compared. Second, because the characters in question are under the control of many genes, (polygenic traits) and for the most part are extremely sensitive to environmental influences, and because many genotypes cannot be distinguished from each other phenotypically, the statistical methods of studying these characters are very complex. Today, however, it is realised that differences between populations transcend differences in size and appearance, and extend to biochemical factors and other Immunochemical properties. Since the 1900's a new class of physical characters has entered ii the field of anthropology; the blood groups* These characters can be more accurately established,are under precise genetic control and are susceptible to statistical analysis and gene counting. Their mode of inheritance is simple, straightforward and usually follows Mendelian laws. The gene frequencies in the population tested can be easily computed from the observed phenotypic frequencies. From the analysis one can hypothesise about the relative influences of natural selection, migration, mutation, population admixture, disease resistance and environmental forces like climate. These biochemical traits are all the more reliable as taxonomic tools as they are genetically determined at conception and remain fixed for life. (Mourant 1954) Together with the blood group systems, and rapidly increasing in importance, is another set of biochemical markers found also in human blood. These are the blood proteins and cellular enzymes. These components of human blood have been found to exhibit hereditary variation that differs among populations. The variant forms occur too frequently to be due to recurrent mutation and can therefore be considered to be polymorphic in man according to Ford's (1940) definition. Blood proteins, like the blood groups, are a much more immediate consequence of the genetic constitution than are the directly observable morphological characters of the body. (Scozzarl et al. 1970) The discovery of these quantitatively and qualitatively different proteins would never have been possible had it not been for the introduction of the technique of starch-gel electrophoresis (Smithies 1955). This sensitive method permits the separation of molecules on the basis of their size as well as electrical charge. Initially it was used for differentiating iii serum protein variants* such as haptoglobin and transferrin. However largely due to the work of Harris and his co - workers, the technique has been extended to the study of the cellular enzymes. Again, the methods of recording the more traditional anthrop• ometric characters have also been refined. Today,reflectance spectrophotometers are used for objectively measuring skin and hair colour. The present study reports upon the survey of selected indigenous inhabitants of the Isle of Man in particular, but also of smaller numbers in Cumbria and South West Scotland, to determine whether these groups exhibit variability in many of the above mentioned physical characters. Chapter one is an account of the physical and human background of the Isle of Man, the centre of study. These two aspects are very important to a study of the population of the Isle of Man because the Island's position in the middle of the North Irish Sea basin has produced varying degrees of social isolation^with consequent marked effects on population growth and movements.