Format

Send to

Choose Destination
See comment in PubMed Commons below
Evolution. 2010 Jun;64(6):1729-47. doi: 10.1111/j.1558-5646.2010.00943.x.

The efficacy of divergence hitchhiking in generating genomic islands during ecological speciation.

Author information

1
Dept. of Biological Sciences, University of Notre Dame, Notre Dame, Indiana 46556, USA. feder.2@nd.edu

Abstract

Genes under divergent selection flow less readily between populations than other loci. This observation has led to verbal "divergence hitchhiking" models of speciation in which decreased interpopulation gene flow surrounding loci under divergent selection can generate large regions of differentiation within the genome (genomic islands). The efficacy of this model in promoting speciation depends on the size of the region affected by divergence hitchhiking. Empirical evidence is mixed, with examples of both large and small genomic islands. To address these empirical discrepancies and to formalize the theory, we present mathematical models of divergence hitchhiking, which examine neutral differentiation around selected sites. For a single locus under selection, regions of differentiation do not extend far along a chromosome away from a selected site unless both effective population sizes and migration rates are low. When multiple loci are considered, regions of differentiation can be larger. However, with many loci under selection, genome-wide divergence occurs and genomic islands are erased. The results show that divergence hitchhiking can generate large regions of differentiation, but that the conditions under which this occurs are limited. Thus, speciation may often require multifarious selection acting on many, isolated and physically unlinked genes. How hitchhiking promotes further adaptive divergence warrants consideration.

[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Loading ...
    Support Center