Genetic studies of human demographic history have a long tradition, one that
began with studies of blood type variation and other protein polymorphisms in
humans and is now largely upheld by research into the uniparentally inherited
mitochondrial DNA (mtDNA) and Y chromosome. However, the field of
human population genetics is currently undergoing a major phase of
broadening, both in its scope and in the technologies involved. Whole genome
single nucleotide polymorphism (SNP) genotyping and ancient DNA analyses
have expanded the horizons of scientific enquiry. Large numbers of high quality
full genome sequences are still just slightly out of reach for wide-scale
population genetic studies, but the genotyping of hundreds of thousands of
SNPs all over the genome has already become a routine.
Especially considering the recent developments in the field, the population
genetic approach has become a powerful way of studying human history. Even
a new term – archaeogenetics – has been coined by Colin Renfrew (Renfrew
and Boyle 2000). The formation of the extant populations of Europe has long
been a focus of attention, with numerous debates, such as those on the mode
and timing of the peopling of Europe and the cultural versus demic diffusion of
the Neolithic, still not settled despite extensive study both in the fields of
archaeology and genetics. Another area of interest is the Caucasus, a region
linking the Near/Middle East and the East European Plain between the Black
and Caspian Seas and exhibiting high ethnic as well as linguistic diversity. So
far, the role of the Caucasus in human dispersals in Eurasia, including the
peopling of East Europe, has remained obscure. Indeed, one may wonder: does
it link or separate the Near/Middle East and East Europe?
The present dissertation aims, firstly, to offer a brief overview of the current
knowledge about genetic research into human demographic history, in particular
concerning Europe and the Caucasus and, secondly, to add new insights to
the understanding of the genetic structuring of western Eurasia. Our novel
results about the phylogeography of Y-chromosomal, mitochondrial DNA and
autosomal variation enhance the current understanding of the genetic heritage of
the Caucasus populations as well as enable comparisons between the Caucasians
and their neighbours, revealing the role of the Caucasus in ancient
human migrations in Eurasia, including the peopling of East Europe. Furthermore,
the spatial and temporal distribution of two Y chromosome haplogroups
widespread in Europe and elsewhere is analysed and discussed in terms of
potential Late Pleistocene and Holocene demographic history of West Eurasian
populations.