Sunday, February 3, 2019

QCB Faculty Candidate Special Seminar | Christian Huber, Ph.D.

Christian Huber
ARC DECRA Fellow, University of Adelaide
Research Profile

Population genomics of selection in natural populations

Thursday February 7, 2019
2 PM
RRI 101

Abstract: Natural selection is one of the cornerstones of modern biology and remains the primary explanation for how species adapt. Population genetic methods have been highly successful in using genetic variation data to quantify the amount and type of natural selection in the genome. However, the main factors that lead to differences in selection strength between species are still unclear. Further, complex demographic history often leads to biased estimates of the rate and strength of selection across the genome. In this talk, I first discuss how modelling population structure is key for quantifying positive selection in the genome. I present a new method for detecting positive selection that is both robust to demography and more powerful than previous approaches. Next, I present a comparative population genomic approach that suggests that amino acid changing mutations in humans are, on average, more deleterious than mutations in Drosophila. More generally, species complexity, as well as the distance of the population to the fitness optimum, are found to be the key drivers of the deleteriousness of new amino-acid mutations. Finally, I present a first estimate of dominance from natural population data and find that mutations are predominantly recessive. Contrary to classical models of the evolution of dominance I suggest that variation in dominance between genes is a consequence of the cost of gene expression.



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