Evolutionary Consequences of Recently Founded Aleut Communities in the Commander and Pribilof Islands

• Main Author: Rubicz, Rohina C.
• Other Authors: Crawford, Michael H, Mielke, James, Hofman, Jack, Benedict, Steve, Redd, Alan
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: University of Kansas 2007
• Subjects: Physical anthropology; aleut; Alaska
• Online Access: http://hdl.handle.net/1808/4055; http://dissertations.umi.com/ku:2222

This study uses molecular genetic markers to investigate the genetic consequences of the founding and other historic events on the Aleut gene pool. Maternal markers (mtDNA RFLPs and sequencing), paternal markers (Y chromosome SNPs and STRs), and biparentally-inherited markers (autosomal STRs, and classic genetic markers from the literature) are characterized to address the questions: 1) is there reduced genetic diversity in recently founded Aleut communities compared to the parental Aleutian Aleut population? 2) How reproductively isolated are these communities? 3) Is there symmetry in maternal versus paternal gene flow? 4) What is the genetic effect of the interaction genetic drift and gene flow? 5) Which of the three aggregates differentiates most from the parental population? Maternal markers for all Aleut populations belong to Native American mtDNA haplogroups A and D, indicating there was no non-Native female gene flow into the population, for individuals claiming Aleut maternal ancestry. In contrast, the majority of paternal markers (73% to 90%) are of non-Aleut origin, due to gene flow from Russians and other non-Aleut males. The Bering community exhibits considerably reduced mtDNA diversity, demonstrated by the fixation of haplogroup D, and gene diversity=0.29, compared to other Aleuts (St. George=0.56, St. Paul=0.72, and Aleutian Aleuts=0.77). This is likely the result of Bering experiencing a founder effect, followed by its closure from other Aleut populations after the U.S. purchase of Alaska in 1867. Meanwhile, the Pribilof communities remained in contact with the Aleutian inhabitants. The low gene diversity, however, is not demonstrated by the paternal markers for the communities (Bering=1.0, St. Paul=0.9591, St. George=0.9167, and Aleutian Aleuts=0.9565), or the autosomal markers (Bering Aleuts= 0.776, and Bering mixed Aleuts=0.882). The results indicate genetic drift may be acting on the maternal lineages, while the opposing evolutionary force of gene flow is affecting the paternal markers. ...