No gene flow. New species.

by Image Editor

Researchers discover mechanism that prevents two species from reproducing

[Via Eureka! Science News – Popular science news]

Cornell researchers have discovered a genetic mechanism in fruit flies that prevents two closely related species from reproducing, a finding that offers clues to how species evolve.

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This is potentially a very important finding, if it carries over to other species and not just fruit flies. Reproductive isolation is often an important aspect of species formation.Once the flow of genes has stopped between two groups, the ability for them to evolve separately occurs.

Alterations in certain areas of the sex chromosomes might be important first steps in reproductive isolation. These areas can diverge fairly rapidly; they develop mutations and additional repetitive sequences very quickly compared to normal regions of the chromosomes.

Thus two isolated groups could develop fairly rapidly. Once separate, they are free to develop much larger changes in their genetic material because there is really no way for them to ever breed again. Thus the genetic sequences diverge even more, with entire regions becoming altered, even those that where mutation accumulate at a slower pace.

It is almost as if the drive it to create species rapidly when gene flow decreases between groups. Create new species rapidly and often.

I wonder how many generations with no gene flow it takes to create a new species by this route?

[Listening to: Tomorrow Never Knows from the album “Revolver [2009 Stereo Remaster]” by The Beatles]