Publication Date

Summer 7-14-2021

Abstract

The last great migration of our species saw humans traverse the Bering landmass from Siberia into the American continents in what has proven to be one of the most profound evolutionary events in modern human history. During the Last Glacial Maximum, a small band of Siberians entered the Beringian corridor, where they persisted, isolated from gene flow, for several thousand years before expansion into the Americas. The particular ecological features of the Beringian environment, coupled with an extended period of isolation at small population size, would have provided evolutionary opportunity for novel genetic variation to arise as both rare standing variants and new mutations were driven to high frequency through neutral and directed processes. This dissertation explores the genomic consequences of the Beringian Migration, identifying a set of group specific alleles (GSAs) that arose during this time and are shared by descendant populations with Native American ancestry. Tests for selection reveal that some of these Beringian variants were likely driven to high frequency by adaptive processes and bioinformatic analyses suggest possible phenotypic pathways related to cardiac processes and melanocyte function appear to be enriched for selected Beringian variants. We specifically investigate the melanoma associated transcript-6 (MEAT6) gene as a candidate for adaptive evolution. Using siRNA transfection, we uncover a significant decrease in melanoma cell proliferation when the MEAT6 transcript was knocked down, conferring a protective effect against melanoma. This result suggests that meaningful phenotypic differences in melanoma may exist among descendant Native American populations due to their unique evolutionary history.

Keywords

beringia, genomics, genomic architecture, adaptive evolution, vitamin d

Document Type

Dissertation

Language

English

Degree Name

Evolutionary Anthropology

Level of Degree

Doctoral

Department Name

Anthropology

First Committee Member (Chair)

Jeffrey C Long

Second Committee Member

Siobhan Mattison

Third Committee Member

Marianne Berwick

Fourth Committee Member

Bruce Huckell

Comments

Pages 344 and 561 missing from the dissertation.

Download

Included in

Anthropology Commons

Share

COinS