Food Bacteria Can Hijack Sexual Behavior of Flies

[n2doc]

By John Timmer, Ars Technica

People tend to focus on Darwin’s ideas about natural selection, but he also spent a portion of The Origin of Species discussing another powerful evolutionary force: sexual selection.

If a species prefers to mate with members that have a specific trait — bright plumage, for example — it won’t take long for that trait to sweep through the species. In the same way, having two different mating preferences in a single population can split it in two in the same way that a geographic barrier can. In both cases, geography and mate choice, the resulting reproductive isolation can ultimately lead to the evolution of new species, as each population undergoes separate genetic changes.

This week, PNAS published a paper showing that this sort of reproductive isolation can take as little as a single generation in flies, because it doesn’t rely on genetic changes in the insects — it’s driven by the bacteria that live on them.

This sort of reproductive isolation isn’t just theory; it’s been demonstrated in the lab. Fruit flies can be grown under different conditions — temperature, humidity, food source — for multiple generations, after which the flies will have a strong preference for mating with those raised under identical conditions. Even when the flies are no longer isolated, they mate as if they were.

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http://www.wired.com/wiredscience/2010/11/fly-sex-bacteria-evolution

One wonders how the junk we are eating is changing our behavior...

[AlecBGreen]

1. very interesting

This will be useful in class when teaching the scientific method and how scientists alter hypotheses in the face of new, unexplained data. Thanks for posting!