Female guppies have evolved a clever way to avoid having inbred offspring: Slow down the sperm of closely-related males, a new study in linkurl:The Proceedings of the Royal Society B;http://rspb.royalsocietypublishing.org/ reports.
Male and female guppies (Poecilia reticulata)
linkurl:Image: Wikimedia Commons;http://commons.wikimedia.org/wiki/File:Guppy_coppia_gialla.jpg
The results are the first direct evidence for a post-mating but pre-zygotic mechanism to avoid producing inbred offspring. It supports the hypothesis that females mate promiscuously as a way to reduce their chances of reproducing with closely related males, the authors report. "It's new and interesting," said linkurl:Bob Montgomerie,;http://www.queensu.ca/biology/people/faculty/montgomerie.html an evolutionary biologist at Queen's University in Ontario, Canada, who was not involved in the research. "But it's not unexpected," he added: If females can prevent fertilization by a close relative, they aren't wasting energy forming a zygote that will likely die due to the accumulation of harmful mutations. Researchers have long suspected that polyandry...
in vitroGasparini, C., and Pilastro A., "Cryptic female preference for genetically unrelated males is mediated by ovarian fluid in the guppy," Proc. R. Soc. B, doi:10.1098/rspb.2010.2369

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