Thursday, April 25, 2013

Lab-meeting on multiple adaptive peaks and predator-mediated natural selection

Posted by Erik Svensson

On Tuesday (April 30, 10.30) I was thinking that we should discuss a short paper that was recently published in Science, showing an empirical example and application of the Adaptive Landscape concept. I choose this paper to demonstrate that the idéa of the adaptive landscape is not just a theoretical construct, but could actually stimulate empirical and experimental studies. This was also the main rationale for the publication of our book on the topic last year, which is cited in the current paper. You will find the Abstract below, and the paper can be reached here. 

As another example of how "landscape thinking" and fitness surfaces can guide empirical work, I will also send around a manucript draft about predator-mediated natural selection in Calopteryx-demoiselles, that stems from the field work former postdoc Shawn Kuchta did in our lab between 2007 and 2009. We would both love to get some input on this manuscript, short or long, either during the lab-meeting or before or after (if you cannot attend). I will send you an e-mail with this paper attached well before the lab-meeting, but if you do not receive it and wish to have a copy, please do not hesitate to send me an e-mail (

Any fika-volunteer?

Vol. 339 no. 6116 pp. 208-211 
DOI: 10.1126/science.1227710

Multiple Fitness Peaks on the Adaptive Landscape Drive Adaptive Radiation in the Wild

The relationship between phenotype and fitness can be visualized as a rugged landscape. Multiple fitness peaks on this landscape are predicted to drive early bursts of niche diversification during adaptive radiation. We measured the adaptive landscape in a nascent adaptive radiation ofCyprinodon pupfishes endemic to San Salvador Island, Bahamas, and found multiple coexisting high-fitness regions driven by increased competition at high densities, supporting the early burst model. Hybrids resembling the generalist phenotype were isolated on a local fitness peak separated by a valley from a higher-fitness region corresponding to trophic specialization. This complex landscape could explain both the rarity of specialists across many similar environments due to stabilizing selection on generalists and the rapid morphological diversification rate of specialists due to their higher fitness.

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