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Natural Selection: experimental evidence
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Do Tephritid flies mimic jumping spiders? Zonosemata
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Coevolution Two or more species. Change in one species serves as a selector for change in the other species. Interplay of changing gene frequencies. Parallel evolutionary paths.
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Models of coevolution
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Phylogenies of coevolving species 1. Perfect congruence between mutualistic species tryptophan
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2. Partial congruence between hosts and parasites
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A famous Müllerian mimicry complex. Each species with subspecies defined by color pattern and geography. What happens at subspecific boundaries?
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Micrurus eryxanthus: Western coral snake Aposematic coloration Problem: how established?
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A mimetic system Batesian and Müllerian Mimicry Aposematic coloration Parallel geographic variation Micrurus 6 species. Highly venomous Fixed front fangs Neotropical Elapidae Pliocercus 1 or 2 species. Mildly venomous Fixed rear fangs Colubridae
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Does aposematic coloration work? Plasticine models Forest floor: on white paper and on forest floor
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Experiment carried out in natural habitat
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Resemblance does not have to be perfect to confer protection Significant differences
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Is avoidance of aposematic coloration innate? Naïve motmots (Neotropical birds) Caged birds presented with: – 1. coral snake models – 2. models of natural prey species.
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