Date Approved

8-2014

Graduate Degree Type

Thesis

Degree Name

Cell and Molecular Biology (M.S.)

Degree Program

Cell and Molecular Biology

Abstract

During the Neolithic transition into the Early Bronze Age (EBA) in the North Pontic steppe region (NPR), people, cultures, and technologies were rapidly changing. Farming was on the decline and Indo-European languages were spreading through the region along with pastoralist way of life. In this study we used mitochondrial DNA (mtDNA) haplotyping to study the people living in the NPR during these times. Additionally, we used next-generation sequencing (NGS) technologies in attempts to develop novel methods to assess the degradation of ancient DNA (aDNA). We extracted ancient mtDNA from remains of 11 individuals belonging to late Neolithic and EBA populations of the NPR. Using single nucleotide polymorphisms (SNPs) as markers, we established mtDNA haplogroups of nine out of 11 individuals. Using our data, as well as mtDNA haplogroup frequencies from literature, we visualized genetic relationships among various Eurasian populations spanning the Mesolithic through EBA using principal component analysis (PCA). We then examined the changes in haplogroup frequencies through time using an FST analysis, comparing representatives of the Yamna (Pit Grave) and Catacomb groups, the main pastoralist EBA cultures of the NPR, and modern European populations. We found genetic evidence through mtDNA haplogroup frequencies and PCA linking the Catacomb people to hunter-gatherer populations from northern Europe and Russia. On the other hand, data on mtDNA haplogroup frequencies of individuals from the Yamna culture associated them with farming and pastoralist type populations from southwest and central Europe. An FST analysis of mtDNA haplogroup frequency distribution showed that the Yamna are most closely related to the Boyko group of ethnic Carpathian highlanders than to other modern European groups used in the study. The Catacomb people appeared genetically different from all other population groups in the FST analysis, including the Yamna group, challenging the current understanding of the relationship between the Yamna and Catacomb populations. Further statistical analysis using an exact test of population differentiation confirmed genetic differences in mtDNA haplogroup frequencies between Yamna and Catacomb. The exact test also revealed a lack of genetic differentiation between the Yamna and the modern Ukrainian population, as well as Lemko, another group of Carpathian highlanders. Data gathered from the NGS aspect of the study was not informative in its original design. Modifications to the methods and techniques outlined in our NGS assay could provide useful information in building a more comprehensive understanding of DNA damage through time.

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