Correlated responses to clonal selection in populations of Daphnia pulicaria Mechanisms of genetic correlation and the creative power of sex
Genetic correlations among traits alter evolutionary trajectories due to indirect selection. Pleiotropy, chance linkage, and selection can all lead to genetic correlations, but have different consequences for phenotypic evolution. We sought to assess the mechanisms contributing to correlations with size at maturity in the cyclic parthenogen Daphnia pulicaria. We selected on size in each of four populations that differ in the frequency of sex, and evaluated correlated responses in a life table. Size at advanced adulthood, reproductive output, and adult growth rate clearly showed greater responses in high-sex populations, with a similar pattern in neonate size and r. This pattern is expected only when trait correlations are favored by selection and the frequency of sex favors the creation and demographic expansion of highly fit clones. Juvenile growth and age at maturity did not diverge consistently. The inter-clutch interval appeared to respond more strongly in low-sex populations, but this was not statistically significant. Our data support the hypothesis that correlated selection is the strongest driver of genetic correlations, and suggest that in organisms with both sexual and asexual reproduction, adaptation can be enhanced by recombination. © 2012 The Authors. Published by Blackwell Publishing Ltd. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
| Main Authors: | , , |
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| Format: | artículo biblioteca |
| Language: | English |
| Published: |
Wiley
2013
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| Subjects: | Body size, Complex traits, Life history, Linkage, Pleiotropy, Recombination, |
| Online Access: | http://hdl.handle.net/20.500.12792/1159 http://hdl.handle.net/10261/291001 |
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