Wednesday, May 21, 2008

Limits on Adaptation of Drosophila species

Check out this article in Science, Low Potential for Climatic Stress Adaptation in a Rainforest Drosophila Species

The article discusses recent interest in resistance evolution in Drosophila birchii. What's interesting here is the limit on evolved resistance, after 30 years of "intense selection" for desiccation resistance. Here is a little abstract of the article. I found it very interesting and ever so slightly related to what we're studying in class / in the text. 

The ability of sensitive rainforest species to evolve in response to climate change is largely unknown. We show that the Australian tropical rainforest fly Drosophila birchii exhibits clinal variation in desiccation resistance, but the most resistant population lacks the ability to evolve further resistance even after intense selection for over 30 generations. Parent-offspring comparisons indicate low heritable variation for this trait but high levels of genetic variation for morphology. D. birchii also exhibits abundant genetic variation at microsatellite loci. The low potential for resistance evolution highlights the importance of assessing evolutionary potential in targeted ecological traits and species from threatened habitats.

Centre for Environmental Stress and Adaptation Research, La Trobe University, Bundoora, Victoria 3086, Australia.

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