| NSF Org: |
OPP Office of Polar Programs (OPP) |
| Recipient: |
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| Initial Amendment Date: | April 2, 2013 |
| Latest Amendment Date: | April 22, 2014 |
| Award Number: | 1203874 |
| Award Instrument: | Continuing Grant |
| Program Manager: |
Anna Kerttula de Echave
OPP Office of Polar Programs (OPP) GEO Directorate for Geosciences |
| Start Date: | April 1, 2013 |
| End Date: | March 31, 2016 (Estimated) |
| Total Intended Award Amount: | $295,535.00 |
| Total Awarded Amount to Date: | $295,535.00 |
| Funds Obligated to Date: |
FY 2014 = $136,527.00 |
| History of Investigator: |
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| Recipient Sponsored Research Office: |
845 N PARK AVE RM 538 TUCSON AZ US 85721 (520)626-6000 |
| Sponsor Congressional District: |
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| Primary Place of Performance: |
239 BSW, #88, 1041 E. Lowell St Tucson AZ US 85721-0088 |
| Primary Place of
Performance Congressional District: |
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| Unique Entity Identifier (UEI): |
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| Parent UEI: |
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| NSF Program(s): |
ASSP-Arctic Social Science, Biological Anthropology |
| Primary Program Source: |
0100XXXXDB NSF RESEARCH & RELATED ACTIVIT |
| Program Reference Code(s): |
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| Program Element Code(s): |
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| Award Agency Code: | 4900 |
| Fund Agency Code: | 4900 |
| Assistance Listing Number(s): | 47.078 |
ABSTRACT
Our species originated in Africa, and subsequently dispersed to all other continents except Antarctica. During this dispersal, human populations were exposed to a variety of climates that differed substantially from those in their African homeland. Nowhere do these climatic conditions differ more dramatically than in the far northern reaches of Siberia. Indeed, humans represent the only primate species other than the Japanese macaque that has adapted to boreal conditions?where temperatures remain far below freezing for more than half the year?pointing to intense selection pressures that likely drove the enhancement of physiological processes that generate and conserve heat. However, despite the fact that humans have lived in cold climates for millennia, we still know very little about how this process of adaptation occurred at the genetic level.
The native populations of Siberia provide the best opportunity to investigate the genetic basis of cold resistance given their long-term residence in some of the coldest climates on earth. While much of northern Europe was under ice throughout the last glacial period, Siberia remained relatively ice free, and archaeological evidence suggests that people inhabited this region for more than 40,000 years. The successful long-term settlement of this area by humans undoubtedly required multiple adaptations to deal with the extended severe cold stress, dramatic variation in photoperiod, and limited and highly variable food resources. This project will gather genome-wide polymorphism data from 15 populations that live across a large area of Siberia, from regions of southern Siberia to the northernmost settlements on the Taymyr peninsula within the Arctic Circle. Patterns of variation in these cold-adapted populations will be compared with those from Central and East Asian populations that live in warmer climates. Particular attention will be paid to genomic regions containing genes that have been previously implicated in cold adaptation, or that function in known pathways connected to energy metabolism or cold-adapted traits. The combination of dense genetic data, wide geographic population coverage, and several powerful methods for detecting the signatures of natural selection will offer the most comprehensive picture of genetic adaptation to cold in humans to date.
PROJECT OUTCOMES REPORT
Disclaimer
This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.
Understanding the genetic basis of adaptation is one of the major goals of evolutionary biology. As modern humans migrated out of Africa, they entered new environments where they had to adapt to different climates and learn to exploit new resources. While some of these adaptations occurred through changing cultural practices and new technologies, the long-term settlement of many areas undoubtedly resulted in natural selection for adaptive genetic variants.
Indigenous Siberians inhabit some of the coldest and most challenging environments on our planet, where mean monthly winter temperatures are often below -40°C, and numerous extreme climate records have been set. Remarkably, these Arctic populations have adapted to chronic and severe cold stress, marked seasonality, dramatic variation in photoperiod, sparse vegetation, and specific diets containing negligible amounts of carbohydrates. As such, they represent a unique opportunity to study natural selection and the genetic basis of local adaptation to extreme conditions.
This project was built on many years of previous research by the Hammer lab and our long-term collaborators at the Institute of Cytology and Genetics in Novosibirsk, Siberia. The major question we address in this project: How do local differences in environment and diet modify the human genome? This study is the first comprehensive analysis of genome-wide SNP variation in a large sample of high-latitude populations from Siberia (267 individuals from 15 indigenous Siberian populations). We have performed the first sequencing of the ‘exome’ (all the expressed genes in the human genome) from two unique populations of Nganasan and Yakut. The Nganasans of the Taimyr Peninsula are the northern most indigenous population in the world; and the Yakuts live in the Sakha Republic (Central Siberia), with the lowest winter temperatures and one of largest temperature differences between winter and summer in the world.
We found several genes that show strong signals of natural selection in Siberians, including genes involved in thyroid function, lipid metabolism, and the vitamin D binding protein gene. Some of these gene sets are related to diet, especially to fat metabolism, consistent with the hypothesis that Siberian populations adapted to a fat-rich animal diet. Interestingly, some of these variants were also found at high frequency in several Native American populations.
We anticipate that the discovery of variants in genes that have played a role in the adaptive process will not only increase our understanding of human diversity, but will stimulate new research on the relationships between genetic variation, diet, and human health. Dramatic changes in traditional lifestyles and diets are occurring around the world. These shifts are being accompanied by increases in obesity and chronic metabolic disorders such as diabetes and hypertension. Often this is strongly connected with the abandonment of traditional dietary practices and the adoption of western diets high in processed foods and sugar. This research should help us to better understand why certain groups are more strongly affected by these changes.
Last Modified: 06/29/2016
Modified by: Michael F Hammer
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