Presentation Detail

Gene Flow and/or Migration

Peter, Benjamin [1], Slatkin, Montgomery [2].

Inferring the origin of a range expansion from genetic data.

We propose a method that uses genetic data to test for the occurrence of a recent range expansion and to infer the location of the origin of the expansion. We introduce a statistic for pairs of populations psi (the directionality index) that detects asymmetries in the two-dimensional allele frequency spectrum caused by the series of founder events that happen during an expansion. Such asymmetry arises because low frequency alleles tend to be lost during founder events, thus creating clines in the frequencies of surviving low-frequency alleles. Using simulations, we further show that psi is more powerful for detecting range expansions than both FST and clines in heterozygosity. We illustrate the utility of psi by applying it to a data set from modern humans and show how we can include more complicated scenarios such as multiple expansion origins or barriers to migration in the model.

1 - UC Berkeley, Integrative Biology, Valley Life Sciences Building, Berkeley, CA, 94704, USA
2 - University of California at Berkeley, Integrative Biology, Berkeley, CA, 94720-3140, USA

Keywords:
migration
human evolution
gene surfing
range expansion
gene flow.

Presentation Type: Regular Oral Presentation
Session: 58
Location: Peruvian B/Snowbird Center
Date: Sunday, June 23rd, 2013
Time: 8:30 AM
Number: 58001
Abstract ID:38
Candidate for Awards:W.D. Hamilton Award for Outstanding Student Presentation