Assortative Mating by Diet in a Phenotypically Unimodal but Ecologically Variable Population of Stickleback
Citations Over TimeTop 10% of 2008 papers
Abstract
Speciation with gene flow may be driven by a combination of positive assortative mating and disruptive selection, particularly if selection and assortative mating act on the same trait, eliminating recombination between ecotype and mating type. Phenotypically unimodal populations of threespine stickleback (Gasterosteus aculeatus) are commonly subject to disruptive selection due to competition for alternate prey. Here we present evidence that stickleback also exhibit assortative mating by diet. Among-individual diet variation leads to variation in stable isotopes, which reflect prey use. We find a significant correlation between the isotopes of males and eggs within their nests. Because egg isotopes are derived from females, this correlation reflects assortative mating between males and females by diet. In concert with disruptive selection, this assortative mating should facilitate divergence. However, the stickleback population remains phenotypically unimodal, highlighting the fact that assortative mating and disruptive selection do not guarantee evolutionary divergence and speciation.
Related Papers
- → Evidence for ecology's role in speciation(2004)477 cited
- → Sympatric Speciation in Threespine Stickleback: Why Not?(2011)51 cited
- → Divergent Selection and Then What Not: The Conundrum of Missing Reproductive Isolation in Misty Lake and Stream Stickleback(2012)22 cited
- → How do natural and sexual selection contribute to sympatric speciation?(2004)48 cited
- → Body size differences do not arise from divergent mate preferences in a species pair of threespine stickleback(2009)18 cited