Social networks have been essential throughout hominin evolution, facilitating cooperative childrearing, transmission of cultural knowledge and the sharing of information and resources. As hominins dispersed out of Africa, these networks needed to be maintained at progressively higher latitudes. The first part of this thesis explores the impact of latitude on brain organisation and the possible implications for social cognition. I hypothesise that the lower temperatures and light levels found at higher latitudes select for larger bodies and visual systems, which in turn necessitate larger somatic and visual brain areas. Using orbit size to index eye and visual cortex size, I demonstrate a robust positive relationship between absolute latitude and orbit volume in recent humans. I show that Neanderthals, who solely inhabited high latitudes, have significantly larger orbits than contemporary anatomically modern humans (AMH), who evolved in lower latitude Africa and had only relatively recently dispersed into higher latitudes. Since Neanderthals and AMH dated 27-75kya have almost identical endocranial volumes, I argue that if a greater proportion of the Neanderthal brain was required for somatic and visual processing, this would reduce the volume of neural tissue available for other functions. Since, according to the Social Brain Hypothesis, neocortex volume is positively associated with social complexity, I propose that Neanderthals might have been limited to smaller social networks than AMH. The second part of the thesis explores the challenge of maintaining social networks across greater geographic distances at higher latitudes, where high travelling costs seem to prevent whole tribes from bonding during periodic aggregations. Using a gas model I predict that at lower latitudes daily subsistence mobility allows sufficient encounters between subgroups for the tribe to maintain connectivity, whereas in (Sub)Arctic biomes additional mechanisms are required to facilitate tribal cohesion. This may explain the apparent ‘explosion’ of Upper Palaeolithic art in Europe: symbolic representations allowed social ties to be sustained in the absence of frequent face-to-face contact. Overall, this thesis demonstrates that latitude may influence both brain organisation and cultural expression and argues that both can have a substantial impact on the maintenance of hominin social networks at high latitudes.

Understanding the evolutionary basis for human-specific phenotypes such as complex speech and language, advanced cognition or the unique preparation of their food is a topic of broad interest. Approaches focusing on comparisons of the genomic DNA (deoxyribonucleic acid) or RNA (ribonucleic acid) sequence between species, individuals or tissues allow for the identification of evolutionary sequence changes, some of these changes may underlie differences in phenotypes. In addition, differences in when, where and how much of a particular gene is present may also contribute to functional changes and therefore also to phenotypic differences. The resources to make such comparisons using genetic data are now available. The genome sequences of a number of outgroups: all living great apes, as well two archaic humans, are now publically available. Studying gene expression on the RNA level - a precursor of the protein expression - is considerably easier and cheaper than the measurement of expression of the protein itself. It has been shown that the RNA and protein expression levels are well correlated and therefore measuring RNA levels provides a good proxy for the expression of the protein. Using high-throughput sequencing techniques, relatively unbiased expression comparison is now possible because the RNA from any species can be sequenced directly, rather than being captured on arrays which are designed based on a particular reference sequence. The aim of this research was to use gene expression as a molecular phenotype to identify changes relevant to human-specific biology and study the difference between humans and their closest living relatives to understand patterns and differences in the gene expression and in gene expression regulation in multiple tissues in primates using high-throughput sequencing techniques. In my thesis, I describe two analyses to address open questions in the field of gene expression and genes expression regulation in humans. In the first part I will analyze how the effect of different diets impact gene expression using a mouse model. Two key components of the human diet that differ substantially from the diet of other primates, the frequent use of meat of many humans and the cooking of their food which is common for almost all human populations, are modeled in the experiment. I tested for their impact on liver gene expression. I found that both the differences in food substrates - meat and tuber - as well as in their preparation affect gene expression in mice significantly. The effect is bigger between food substrates than between methods of preparation. Differentially expressed genes between food substrates and food preparation were predominantly related to metabolic functions. In addition, immune-genes showed differential expression between the comparisons of raw meat to both, raw tuber and cooked meat, respectively. The results indicate that different food substrates and food preparations activate different metabolic pathways and that the cooking of food and particularly of meat has an influence on the immune also changes immune-reactions of the body. I showed that expression differences in these mice are correlated with the differences observed between humans and other primates, and that there is evidence that adaptation to these diets dates to more than 300.000 years. Finally, I showed that transcription factors play in important role in regulation of gene expression with respect to different food preparation. In the second part I analyzed the expression of one key regulator of gene expression: microRNAs (miRNAs). Using miRNA expression data from multiple primate species and for multiple tissues I found that expression differences vary between tissues. While heart and brain show only few expression differences between primates, other tissues are more variable in expression. The most extreme expression differences in all three primate species were found in the brain, which may reflect the importance of miRNAs in the regulation of gene expression in the brain. Expression differences in testis were significantly larger between humans and macaques than between chimpanzees and macaques, indicating that miRNAs evolved differently in human compared to chimpanzees. MiRNA expression differences were correlated with expression differences of their target genes genome-wide which underlines the regulatory importance of miRNAs. I also showed that differentially expressed miRNAs between species/tissues preferentially targeted transcription factors, which are important gene expression regulators as well. This finding that suggests complex regulatory pathways involving both miRNAs and transcription factors in the control of gene expression. Finally, I used the miRNA sequencing data to annotate new miRNAs in primates and was able to increase the number of annotated miRNAs substantially, especially for the non-human primates which were previously not extensively annotated. The overlap of miRNAs annotated in multiple primate species thereby also increased which will support future studies to investigate the evolutionary changes of miRNAs between these primates.

abstract: A variety of studies have shown that the tendency toward nicotine dependence has a genetic component. The work described in this thesis addresses three separate questions: i) are there unidentified SNPs in the nicotinic receptors or other genes that contribute to the risk for nicotine dependence; ii) is there evidence of ongoing selection at nicotinic receptor loci; and, iii) since nicotine dependence is unlikely to be the phenotype undergoing selection, is a positive effect on memory or cognition the selected phenotype. I first undertook a genome –wide association scan of imputed data using samples from the Collaborative Study of the Genetics of Nicotine Dependence (COGEND). A novel association was found between nicotine dependence and SNPs at 13q31. The genes at this newly associated locus on chromosome 13 encode a group of micro-RNAs and a member of the glypican gene family. These are among the first findings to implicate a non-candidate gene in risk for nicotine dependence. I applied several complimentary methods to sequence data from the 1000 Genomes Project to test for evidence of selection at the nicotinic receptor loci. I found strong evidence for selection for alleles in the nicotinic receptor cluster on chromosome 8 that confer risk of nicotine dependence. I then used the dataset from the Collaborative Studies on the Genetics of Alcoholism (COGA) and looked for an association between neuropsychological phenotypes and SNPs conferring risk of nicotine dependence. One SNP passed multiple test correction for association with WAIS digit symbol score. This SNP is not itself associated with nicotine dependence but is in reasonable (r 2 = 0.75) LD with SNPs that are associated with nicotine dependence. These data suggest at best, a weak correlation between nicotine dependence and any of the tested cognitive phenotypes. Given the reproducible finding of an inverse relationship between SNPs associated with risk for nicotine dependence and cocaine dependence, I hypothesize that the apparently detrimental phenotype of nicotine dependence may confer decreased risk for cocaine dependence. As cocaine use impairs the positive rewards associated with social interactions, reducing the risk of cocaine addiction may be beneficial to both the individual and the group. / Dissertation/Thesis / Ph.D. Anthropology 2014

The ability to retrieve DNA from the skeletal remains of ancient humans has yielded many insights into the relationship between humans living today and our nearest evolutionary relatives, the Neandertals and Denisovans. Two important insights emerged from the first high-quality genome sequences of Neandertals and Denisovans: 1) these archaic humans had very low genetic diversity in comparison to most populations of present-day humans, and 2) there was gene flow from archaic humans into the ancestors of present-day people. In my thesis, I explored aspects of both these insights. In my first project, I analysed the consequences of low genetic diversity of archaic humans for immune genes, using genetic diversity in protein-coding genes (‘gene diversity’) as a proxy for functional diversity. I conclude that low gene diversity in archaic humans did not affect immune genes more severely than any other class of protein-coding genes. I then show that the MHC genes, that typical have high genetic diversity and are a component of the adaptive immune system, have substantially higher gene diversity than expected from the genome-wide gene diversity in archaic humans. Moreover, I find no detectable reduction in gene diversity between two Neandertals that lived more than 70,000 years apart. This is first evidence indicating that diversity in late Neandertals did not decrease over the last ~100,000 years of their existence, which would be expected if low gene diversity had played a considerable role in Neandertal extinction, as has been proposed. In my second project I analysed genomic regions depleted of both Neandertal and Denisovan ancestry in the genomes of humans living today (‘shared deserts’). It has been suggested that shared deserts reflect incompatibilities between archaic humans and the ancestors of present-day humans, and were created by negative selection against archaic alleles. By analysing archaic ancestry in almost 2,000 published present-day human genomes, including 155 published genomes from Oceania, I generated a further refined set of genomic regions that are most depleted of archaic ancestry. I discuss candidate variants in these regions that may underlie important phenotypic or functional differences between archaic and modern humans, such as in the brain-expressed genes CADM2 and KCND2, and propose this refined list as a set of candidates for future molecular testing.:Bibliographische Darstellung iii Table of contents iv Summary 8 Zusammenfassung 14 1. Introduction 21 1.1. A strange fossil and its genome 21 1.2. Archaic humans had low genetic diversity 26 1.3. Evidence of gene flow between archaic humans and AMH 29 1.3.1. Identification of archaic sequence and its impact on humans today 32 1.3.1.1. The distribution of archaic sequence in AMH is heterogeneous 34 1.3.1.2. Negative selection against introgressed archaic sequence 37 1.3.1.3. Adaptive introgression: Archaic sequence under positive selection in AMH 39 1.3.1.4. Association of introgressed variants with phenotypes of present-day people 41 1.3.2. Deserts: Gene flow left regions depleted of archaic introgression 43 2. Thesis outline 46 3. Methods 47 3.1. Methods for study of immune gene diversity 47 3.1.1. Data 47 3.1.2. Measure of gene diversity 47 3.1.3. Diversity in innate immune and MHC genes 48 3.1.4. GO enrichment analysis 49 3.2. Methods for study of deserts of archaic ancestry 50 3.2.1. Data sets and processing 50 3.2.2. Identification of introgressed haplotypes 51 3.2.2.1. Hidden Markov Model (HMM) 51 3.2.2.2. Probability cut-off for haplotypes to be archaic 51 3.2.3. Reanalysis of published deserts of archaic ancestry 52 3.2.3.1. Shared deserts 52 3.2.3.2. Sliding windows 52 3.2.3.3. Mean percentage introgression 53 3.2.3.4. Comparison to random regions 53 3.2.3.5. Definition of refined shared desert regions 54 3.2.3.6. Overlap of refined shared deserts with genes 54 3.2.3.7. Enrichment analyses in refined shared desert regions 55 3.2.3.8. Overlap with regions under ancient positive selection on the AMH lineage 55 3.2.3.9. Overlap with (nearly) fixed differences between present-day and archaic humans 56 4. Results 57 4.1. Immune gene diversity in archaic and present-day humans 57 4.1.1. Abstract 58 4.1.2. Introduction 59 4.1.3. Results 61 4.1.3.1. Archaic humans had lower overall gene diversity than present-day humans 61 4.1.3.2. Archaic humans had similarly low gene diversity in innate immune genes compared with non-immune genes 62 4.1.3.3. High MHC gene diversity in archaic humans 64 4.1.3.4. Genes with highest/lowest diversity show similar GO enrichments in archaic and present-day humans 66 4.1.4. Discussion 69 4.1.5. Supplementary results 71 4.1.6. Acknowledgements and author contributions 72 4.2. Refining deserts of archaic ancestry 73 4.2.1. Abstract 73 4.2.2. Introduction 75 4.2.3. Results 78 4.2.3.1. Genome-wide patterns of archaic introgression are consistent with previous maps 78 4.2.3.2. The published shared desert regions are not the most depleted regions in the genome 79 4.2.3.3. Levels of archaic introgression in shared deserts for the IGDP data set are comparable 82 4.2.3.4. Shared deserts unique to either the Vernot or Sankararaman set have lower mean percentage introgression 84 4.2.3.5. Refined shared deserts 84 4.2.3.6. Overlap of refined shared deserts with genes 87 4.2.3.7. Enrichment analyses 88 4.2.3.8. Overlap with regions under ancient positive selection on the AMH lineage 89 4.2.3.9. Overlap of refined shared deserts with (nearly) fixed differences (nFD) 89 4.2.4. Discussion 94 4.2.5. Acknowledgements 98 5. Discussion and outlook 99 5.1. Interpreting immune gene diversity in archaic humans 99 5.2. Implications from refined deserts of archaic ancestry 104 5.2.1. Comments on the origin of desert regions 106 5.2.2. Candidates for functional molecular testing in refined deserts 107 5.2.3. Future directions in the characterisation and definition of shared deserts 110 5.3. Future directions beyond shared deserts 115 6. Outlook: Molecular functional testing of candidate variants 118 7. Conclusions and final remark 122 8. Supplementary information (SI) 124 8.1. SI: Immune gene diversity in archaic and present-day humans 124 8.2. SI: Refining deserts of archaic ancestry 152 Index of figures 216 Index of tables 218 Index of supplementary data files 220 References 221 Abbreviations 240 Acknowledgements/Danksagungen 242 Curriculum vitae 244 Publications 248 Selected talks 249 Poster presentations 249 Selbstständigkeitserklärung 250 Nachweis über Anteile der Co-Autor:innen 251

abstract: Evolutionary and economic theories of fertility variation argue that novel subsistence opportunities associated with market economies shape reproduction in ways that both increase parental investment per child and lower overall fertility. I use demographic and ethnographic data from Guatemala as a case study to illustrate how ethnic inequalities in accessing market opportunities have shaped demographic variation and the perceptions of parental investments. I then discuss two projects that use secondary data sets to address issues of conceptualizing and operationalizing market opportunities in national and cross-population comparative work. The first argues that social relationships are critical means of accessing market opportunities, and uses Guatemala household stocks of certain forms of relational wealth are associated with greater parental investments in education. The second focuses on a methodological issue in how common measures of wealth in comparative demographic studies conflate economic capacity with market opportunities, and how this conceptual confusion biases our interpretations of the observed links between wealth and fertility over the course of the demographic transition. / Dissertation/Thesis / Doctoral Dissertation Anthropology 2019

Understanding the evolutionary basis for human-specific phenotypes such as complex speech and language, advanced cognition or the unique preparation of their food is a topic of broad interest. Approaches focusing on comparisons of the genomic DNA (deoxyribonucleic acid) or RNA (ribonucleic acid) sequence between species, individuals or tissues allow for the identification of evolutionary sequence changes, some of these changes may underlie differences in phenotypes. In addition, differences in when, where and how much of a particular gene is present may also contribute to functional changes and therefore also to phenotypic differences. The resources to make such comparisons using genetic data are now available. The genome sequences of a number of outgroups: all living great apes, as well two archaic humans, are now publically available. Studying gene expression on the RNA level - a precursor of the protein expression - is considerably easier and cheaper than the measurement of expression of the protein itself. It has been shown that the RNA and protein expression levels are well correlated and therefore measuring RNA levels provides a good proxy for the expression of the protein. Using high-throughput sequencing techniques, relatively unbiased expression comparison is now possible because the RNA from any species can be sequenced directly, rather than being captured on arrays which are designed based on a particular reference sequence. The aim of this research was to use gene expression as a molecular phenotype to identify changes relevant to human-specific biology and study the difference between humans and their closest living relatives to understand patterns and differences in the gene expression and in gene expression regulation in multiple tissues in primates using high-throughput sequencing techniques. In my thesis, I describe two analyses to address open questions in the field of gene expression and genes expression regulation in humans. In the first part I will analyze how the effect of different diets impact gene expression using a mouse model. Two key components of the human diet that differ substantially from the diet of other primates, the frequent use of meat of many humans and the cooking of their food which is common for almost all human populations, are modeled in the experiment. I tested for their impact on liver gene expression. I found that both the differences in food substrates - meat and tuber - as well as in their preparation affect gene expression in mice significantly. The effect is bigger between food substrates than between methods of preparation. Differentially expressed genes between food substrates and food preparation were predominantly related to metabolic functions. In addition, immune-genes showed differential expression between the comparisons of raw meat to both, raw tuber and cooked meat, respectively. The results indicate that different food substrates and food preparations activate different metabolic pathways and that the cooking of food and particularly of meat has an influence on the immune also changes immune-reactions of the body. I showed that expression differences in these mice are correlated with the differences observed between humans and other primates, and that there is evidence that adaptation to these diets dates to more than 300.000 years. Finally, I showed that transcription factors play in important role in regulation of gene expression with respect to different food preparation. In the second part I analyzed the expression of one key regulator of gene expression: microRNAs (miRNAs). Using miRNA expression data from multiple primate species and for multiple tissues I found that expression differences vary between tissues. While heart and brain show only few expression differences between primates, other tissues are more variable in expression. The most extreme expression differences in all three primate species were found in the brain, which may reflect the importance of miRNAs in the regulation of gene expression in the brain. Expression differences in testis were significantly larger between humans and macaques than between chimpanzees and macaques, indicating that miRNAs evolved differently in human compared to chimpanzees. MiRNA expression differences were correlated with expression differences of their target genes genome-wide which underlines the regulatory importance of miRNAs. I also showed that differentially expressed miRNAs between species/tissues preferentially targeted transcription factors, which are important gene expression regulators as well. This finding that suggests complex regulatory pathways involving both miRNAs and transcription factors in the control of gene expression. Finally, I used the miRNA sequencing data to annotate new miRNAs in primates and was able to increase the number of annotated miRNAs substantially, especially for the non-human primates which were previously not extensively annotated. The overlap of miRNAs annotated in multiple primate species thereby also increased which will support future studies to investigate the evolutionary changes of miRNAs between these primates.

What motivates extreme pro-group action, such as heroism and self-sacrifice on the battlefield? Despite much scholarly attention in recent years, the question is yet to be fully explained. Recent research suggests that shared dysphoric experiences are one way of generating identity fusion, a visceral sense of 'oneness' between individual and group that has been shown to motivate willingness to fight and die for the group. Using two special populations - British and Brazilian football fans - this thesis investigates the causes and consequences of fusion. Football fan cultures are diverse, globally popular, and ripe for examining intergroup conflict. This thesis focuses on two related components of the 'shared dysphoria pathway' to fusion: emotional arousal (e.g. watching one's team suffer a particularly bitter defeat) and the sense of 'self-transformativeness' that ensues from intense, shared experiences. Across four studies, it is shown that for some individuals, sharing the agony of defeat can be emotionally and physiologically arousing to such a degree so as to transform their sense of personal identity. In turn, this leads to a more porous boundary between group and individual identities, i.e. individuals become 'fused' with their groups. Fused people are documented as engaging in some of the most extreme and potentially dangerous social behaviours we know. Two related consequences of fusion are examined: extreme pro-group action and outgroup hostility. Football hooliganism is a persistent, global problem, which is addressed in a fifth study. This thesis refutes past work suggesting that hooligans are social misfits, instead contending that hooligans are especially fused to their group and motivated to defend their 'brothers-in-arms', which results in outgroup violence. These findings suggest that a more thorough understanding of the causes and consequences of fusion could conceivably impact a great many areas, perhaps most importantly conflict resolution and policies relating to intergroup conflict.

Human sociality, with its wide scope, early ontogeny and pervasiveness across cultures, is remarkable from an evolutionary perspective. We form bonds with other individuals and live in large social groups. We help, empathise with and share our resources with others, who are unfamiliar and genetically unrelated to us. It has been suggested that interpersonal coordination and rhythmic synchronisation of movements may be one proximate mechanism that enables such widespread human sociality and facilitates cooperation. In the last decade, considerable research has examined the effect of movement synchrony on social bonding and cooperation. However, when this thesis started, there was virtually no experimental study investigating the ontogeny of the movement synchrony-social bonding link, which is proposed to have deep evolutionary roots and important, long-lasting consequences in social life. This thesis aims to investigate the effects of movement synchrony on social bonding and cooperative behaviour across different time points in ontogeny. Three experimental studies were conducted examining infancy, early childhood and middle childhood. Each study explored a different aspect of social bonding and cooperation based on the motor, social and cognitive developments that mark that age group. Study 1a found that at 12 months of age, infants prefer individuals who move in synchrony with them, when the individuals are social entities, but not when they are non-social. Study 1b showed no preferences for synchrony at 9 months in either social or non-social contexts, however. Study 2 revealed that in early childhood, performing synchronous movements actively with a peer facilitates helping behaviour among the children, as well as eye contact and mutual smiling during the interaction. Finally, Study 3 showed that the social bonding effects of movement synchrony applied to inter- group settings and that performing synchronous movements with out-groups increased bonding towards the out-group in middle childhood. This thesis followed an interdisciplinary, integrative and naturalistic approach, where (i) literature from a wide range of disciplines motivated and guided the present research; (ii) links between motor, social and cognitive aspects of development, which are often investigated separately, are formed; and (iii) the experiments were designed in ways that represent the real-life occurrences of the investigated phenomena. The current findings provide the first substantial evidence that movement synchrony facilitates social bonding and cooperation in childhood and thereby provides a foundation for future research.

Social theorists have long argued that literacy is one of the principal causes and hallmark features of complex society. However, the relationship between literacy and social complexity remains poorly understood because the relevant data have not been assembled in a way that would allow competing hypotheses to be adjudicated. The project set out in this thesis provides a novel account of the multiple origins of literate behaviour around the globe, the principal mechanisms of its cultural transmission, and its relationship with the cultural evolution of large-group human cooperation and complex forms of socio-political organisation. A multi-method large-scale cross-cultural approach provided the data necessary to achieve these objectives. Evidence from the societies within which literate behaviour first emerged, and from a representative sample of ethnographically-attested societies worldwide (n=74), indicates that literate behaviour emerged through the routinization of rituals and pre-literate sign systems, eventually spreading more widely through classical religions. Cross-cultural evidence also suggests that literacy assumed a wide variety of forms and socio-political functions, particularly in large, complex groups, extending evolved psychological mechanisms for cooperation, which include reciprocity, reputation formation and maintenance systems, social norms and norm enforcement systems, and group identification. Finally, the results of a cross-cultural historical survey of first-generation states (n=10) reveal that simple models assuming single cause-and-effect relationships between literacy and complex forms of socio-political organisation must be rejected. Instead, literacy and first-generation state-level polities appear to have interacted in a complex positive feedback loop. This thesis contributes to the wider goal of transforming social and cultural anthropology into a cumulative and rapid-discovery science.