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Allopatric speciation in a changing environment

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## Allopatric speciation in a changing environment

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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