Genes, Fertility and Social Change among High Altitude Communities in Nepal
I am currently working with Dr. Cynthia Beall (Case Western Reserve University) and Dr. Geoff Childs (Washington University – St. Louis) on a National Science Foundation grant that involved several months of field research in Nepal this year, in Lode Tsho Dun and the Muktinath Valley regions of Mustang District and in Nubri and Tsum valleys of Gorkha District.
Tibetans have lived at altitudes above 3000m for at least 10,000 years. Consequently they have distinctive biological traits including unexpectedly low levels of hemoglobin, the molecule that carries oxygen. Genes accounting for such hemoglobin levels were recently identified and occur at uniquely high frequency among Tibetans. The likely mechanism for this high frequency is higher fertility and child survival for those people with the low-hemoglobin forms of those genes. This research uses a biocultural approach to test the hypothesis that Tibetan women at high altitude in Nepal with low-hemoglobin variants of specific genes have more surviving children than those with the other variants. This research also recognizes the many cultural and socioeconomic factors that influence reproductive history, fertility, and child survival. The expected results of this study will connect a severe environmental stress to biological and genetic variation and reproductive success to build a case for natural selection operating in a human population and improve scientific understanding of the processes of adapting to new environments. The study has also included ethnographic research focusing on social and generational change among Mustangi women, in terms of their livelihood strategies, access to biomedical health care, and approaches to pregnancy, childbirth, and public health. I hope this research will complement and lay the foundation for future comparative research I aim to conduct between Nepal and individuals from Mustang, Nepal, now residing in the US.