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Allopatric speciation in a changing environment. T. Janzen 1 , L.S. Molleman 2 , R.S.Etienne 1 1 Community and Conservation Ecology Group 2 Theoretical Biology. Picture courtesy Jen Reynolds. Allopatric speciation. Allopatric speciation. We are drifting apart!. Don’t be so selective!.
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Allopatric speciation in a changing environment T. Janzen1, L.S. Molleman2, R.S.Etienne1 1Community and Conservation EcologyGroup 2TheoreticalBiology Picture courtesy Jen Reynolds
Allopatric speciation We are drifting apart! Don’t be so selective!
Allopatric speciation and biodiversity • Species pump (Rossiter 1996) • Changing habitat sizes due to: • Temperature changes • Water level changes • Fragmentation of host species
Anolis Anolis allisoni Anolis porcatus Glor et al. 2004 Proc. B.
Example Anolis Glor et al. 2004 Proc. B.
Eretmodini Ruberet al. 1999 PNAS
Research question • Towhichextent does allopatricspeciationmediatedby a changing environment shapebiodiversity?
Intermezzo! Approximate Bayesian Computation
Why or when? • “normal” situation: • Tractable model • Deterministic outcome • Easy to calculate optimum (explicit likelihood) • “simulation” situation • High stochasticity • Hard to find optimal parameter combination • Brute force too much work • Impossible to calculate likelihood Hartig et al. 2011 Ecol. Let.
ABC parameter estimation • Start with parameter combination A • Run simulations S with A + random noise (r) • if S(A+r) < ε • Store A+r • A = A + r • Go to 2. Hartig et al. 2011 Ecol. Let.
Chosen summary statistic: LTT Sturmbauer et al. 2010
Conclusionandprospects • Allopatricspeciationthrough a changing environment canbe important in generatingbiodiversity • Expand the model by: • Using empirical water level change data • Addingdiversity dependent speciation • Implementing explicit population size • Adding multiple layers • Asymmetric pocket setup
Eretmoduscyanostictus Ruberet al. 1999