Understanding the success of the human species is central to evolutionary anthropology. While we share many traits with our relatives the great apes, only humans migrated to all corners of the earth and domesticated other species, leading to the emergence of complex societies. Investigations into human genomes have shown that they are a rich source of information for insights into our past. However, for a complete understanding of human evolution it is necessary to look beyond our own genomes. This thesis is about using comparative genomics to place human evolution within a wider context by studying adaptation in our closest living relatives and in the species that we domesticated.
In the first study, I investigate the genetic changes involved in the earliest stages of dog domestication. Using a global sample of dog and wolf genomes I identify regions that are highly diverged between these species. I find that selection in the initial stages of dog domestication likely involved genes involved in the fight-or-flight response, advancing our understanding of this process.
In the second study, I look for commonalities in the genetic changes that occurred during animal domestication across species. I compare genome sequences from experimentally and historically domesticated species. I identify genes and variants that may underlie the phenotypic changes that occurred during domestication. I find evidence of biological pathways that appear to always be involved in the domestication process.
In the third study, I characterise the signatures of natural selection in all major Hominidae lineages using population genomic data. I find that most signatures of positive selection are species specific, although some loci appear to be selected across several lineages. I determine that the efficacy of selection varies between species and is significantly correlated with long-term effective population size. These results contribute to a more complete understanding of human evolution.
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This thesis is based on the following manuscripts:
1. Cagan A & Blass T. (2016) Identification of genomic variants putatively targeted by selection during
dog domestication. BMC Evolutionary Biology,16:1.
2. Cagan A, Albert FW, Plyusnina I, Trut L, Renaud G, Romagné F, Wiebe V, Kozhemjakina R, Gulevich R, Trapezov O, Yudin N, Alekhina T, Aitnazarov R, Trapezova L, Herbeck Y, Schöneberg T, Pääbo S. Genes and pathways selected during animal domestication. Submitted to eLife.
3. Cagan A, Theunert C, Laayouni H, Santpere G, Pybus M, Casals F, Prüfer K, Navarro A, Marques-Bonet T, Bertranpetit J, Andrés AM. (2016). Natural Selection in the Great Apes. Molecular Biology and Evolution, 33:3268-3283.:Summary 1
Zusammenfassung 8
Chapter 1 Identification of genomic variants putatively targeted by selection during dog domestication 16
Chapter 2 Genes and pathways selected during animal domestication 38
Chapter 3 Natural Selection in the Great Apes 73
References 149
Acknowledgments 152
Curriculum Vitae 153
Declaration of Independence 156
Author Contribution Statements 157
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa:de:qucosa:17017 |
| Date | 15 January 2018 |
| Creators | Cagan, Alexander |
| Contributors | Universität Leipzig |
| Source Sets | Hochschulschriftenserver (HSSS) der SLUB Dresden |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, doc-type:doctoralThesis, info:eu-repo/semantics/doctoralThesis, doc-type:Text |
| Rights | info:eu-repo/semantics/openAccess |
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