Size-structured evolution and speciation

Section Population Biology, University of Amsterdam, The Netherlands

David Claessen

David Claessen

There are numerous examples of size-structured populations where individuals sequentially exploit several niches in the course of their life history. Efficient exploitation of these niches generally requires specific morphological adaptations. Since individuals have limited scope for changing their morphology as they grow, increased efficiency in one niche generally implies decreased efficiency in another. In this project I explore potential evolutionary consequences of such life-history tradeoffs. In particular, I investigate life-history adaptation in simple size-structure population models in which individuals can exploit a primary niche while they are small whereas a second niche becomes gradually accessible only beyond a certain body size. My research focuses on the following questions: (1) Can evolution in the first niche alone lead to invasion of the second niche? (2) In a system with two niches, can life-history evolution lead to evolutionary branching and subsequent speciation? (3) After branching, does evolution of the first-niche specialist drive the second-niche occupant to extinction? (4) Can this evolutionary dynamic result in repeated branching and cyclic evolution?

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Last edited: 03 June 2016

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