Genetic structure and trait estimation in ancient Europeans

Abstract

The study of ancient human populations have mostly been carried out, until recently, by historians through the study of written records and ancient manufacts. Thanks to recent technological and theoretical advancements in genetics, it is now possible to support these studies and uncover new insights into human prehistory. The field of ancient genomics is in a phase of continuous progress and recently has become able to describe phenomena such as fine-population structure, phenotypic traits and demographic analyses. By investigating these features of a large set of ancient individuals I will address in this thesis events that shaped the structure, and traits of ancient European populations.

In the first chapter I present the analysis of novel genomic data derived from three ancient Maltese. In this analysis I describe how these individuals were very similar to other Neolithic European populations. I also show how these ancient Maltese possessed one of the lowest western hunter-gatherer ancestry components among contemporary populations. This is of great interest as it points to recent isolation of this group.

In the second chapter I will use a prediction method to increase the quality of ancient genetic data. I then exploit these diploid genome wide data to uncover the fine-structure and demography of ancient European populations. This shows that ancient Neolithic Europeans show a structure with similarities to modern populations, a recapitulation probably as a result of geographic barriers. I also perform a demographic analysis which identifies inbreeding and restricted population sizes in specific Neolithic populations.

In the third chapter I study phenotypic traits in ancient Western Eurasian populations. First I demonstrate how traits such as height can be reliably estimated in ancient populations. I then use regression analyses to describe how this trait changed across time. Finally I describe a body mass index analysis in ancient Maltese and I compare the results with other Neolithic Europeans.