Doctoral Dissertation Improvement: Population Structure and Demographic History of Prehistoric Alaskan Populations Using Ancient DNA and Cranial Morphology

点击翻译按钮获取中文摘要

One of the long standing questions in anthropological science is the correlation over time between biological change and associated material culture. When presented with evidence for replacement of associated technology and cultural attributes, to what extent can the assumption be made that the populations have been replaced as well? Since the initial excavations at Point Hope, Alaska by Larsen and Rainey in 1942, scientists have examined the relationship between pre-contact Tigara (800-300yBP) and Ipiutak (2100-1300 yr BP) material cultures. Based on carbon 14 dates and associated archaeology, these two groups have both distinct temporal and cultural affiliations. While the associated archaeology suggests a cultural change at Point Hope between 1200-600 yr BP, the relationship between this cultural shift and any human biological changes is not clear. The primary goal of this research is to evaluate alternative hypotheses concerning population continuity by quantifying the molecular and morphological differences between the Ipiutak and Tigara populations. The purpose for doing this is two-fold: to assess whether genetic differentiation through time tracks with cultural attribute changes at Point Hope, and to make a methodological comparison between different types of genetic data used to explore population structure changes over time. Morphological variation in discrete and quantitative cranial traits will be used in conjunction with ancient mitochondrial DNA sequence variation in order to quantify population structure changes between the two time periods. Population changes will then be placed in a broader biological context through comparison with other Circum-Arctic and Native American populations.With a recent upsurge in interest of the impact of climate change on the environment, this is an appropriate time to get an historical overview of how environmental dynamics have affected population structure and cultural lifeways over time. This research will lead to new insights concerning how historic populations have dealt with environmental difficulties through migration and cultural adaptation. The unique relationship of the sample populations, located at the same coastal Arctic site yet separated by over 1000 years, presents a unique opportunity for applying morphological and molecular analysis methods for addressing issues of population continuity over time through periods of environmental instability. In addition, this research will provide new molecular data from historical Arctic populations. These analyses will help us better understand the radiation of human biological diversity, providing new insights into the correlation between genetic and cultural change, with applications to similar contexts where this relationship is important to understanding population dynamics.Results of this research will have considerable broader impact. All data and results will be presented to members of the Point Hope Inupiat; data on mtDNA will also be made available to the publicly accessible genbank and American Museum of Natural History's genetic data bases. These data will shed light on the radiation of human biological diversity, providing new insights into the relationship(s) between genetic and cultural change, and facilitating broader understanding of population dynamics.