Lab-meeting on November 22: talk on sexual dimorphism in amphibians by Stephen De Lisle

 

Posted by Erik Svensson

Next week's EXEB-meeting will deal with the evolutionary ecology of sexual dimorphism by new postdoc Stephen De Lisle, who recently defended his PhD at Toronto University in Canada, under the supervision of Prof. Locke Rowe. Stephen has worked with amphibians, particularly newts, using a combination of experiments in mesocosms on single species, and phylogenetic comparative methods of amphibian diversification. An Abstract is appended below.

Time: Tuesday, November 22, 10.00

Place: "Darwin", 2nd floor, Ecology Building

   Ecological Aspects of Sexual Dimorphism

    Abstract:

Sexual dimorphism represents a striking source of diversity in nature, and much of this diversity cannot be fully explained by the direct effects of sexual selection.  This talk focuses on empirically testing and conceptually unifying some of the non-exclusive adaptive causes of sexual dimorphism. First, I present evidence from a newt indicating significant ecological sexual dimorphism and a possible role for at least some direct ecological causal component of dimorphism. I propose a framework for demonstrating an ecological cause of sexual dimorphism, via character displacement between the sexes, and marshal the first direct evidence in support of this hypothesis. I expand this program to examine how competition-driven disruptive selection, ecological sexual dimorphism and speciation interact during the early stages of adaptive radiation in newts.  These analyses suggest clade-wide character displacement between the sexes, and that evolution of ecological sexual dimorphism may play a key role in niche divergence among nascent species. Finally, I extend the test of dimorphism’s role in diversification to a higher level of organization, across Amphibians. I show that the evolution of sexual dimorphism is and has been a key driver of amphibian diversification by increasing speciation rates and reducing extinction.  These results suggest the novel hypothesis that sexual dimorphism may promote diversification by allowing lineages to exploit sex-specific ecological opportunity. The general conclusions are that sexual dimorphism can have significant ecological impact and even direct ecological causes, and contra traditional views, the evolution of sexual dimorphism in ecologically important traits can have important positive impacts on adaptive diversification.

Welcome Stephen De Lisle - new postdoc!

Posted by Erik Svensson 

I am pleased to introduce my new postdoc Stephen De Lisle, who recently defended his postdoc at University of Toronto, under the supervision of Prof. Locke Rowe. Stephen has a strong experimental evolutionary ecology background, complemented with skills in phylogenetic comparative methods and hence will fit well in to overall research profile of both my lab and the EXEB-environment in general. Stephen will stay in Lund for at least two years from now on, thanks to a large international collaborative grant that Tobias Uller obtained together with me, Charlie Cornwallis and Per Lundberg. Stephen will present some of his thesis research on next year's EXEB-meeting (Tuesday, November 22), which will follow in a separate blogpost. 

About Stephen's research, in his own words:

I am an evolutionary ecologist interested in understanding the adaptive origins of phenotypic diversity. Although my interests are broad, much of my research has focused on testing non-traditional models of sexual dimorphism and understanding how the evolution of such ‘ecological’ sexual dimorphisms may or may not influence the structure of ecological communities and the dynamics of evolutionary radiation.  I do this using a combination of experimental and comparative approached that bridge community ecology, microevolution, and macroevolution.