"The evolution of genetic architecture across spatial scales"Flintham, EwanIn patch- or habitat-structured populations, different ecological processes lead to polymorphism at different spatial scales. While spatial heterogeneity and divergent selection favours phenotypic variation between patches, local competition and negative frequency-dependent selection promotes variation within patches. In both cases, this polymorphism drives selection on genetic architecture to minimise the break-up of adaptive allele combinations during hybridisation between different phenotypic morphs. Yet prior theory has looked at the effects of dispersal, divergent selection and negative frequency-dependent selection on genetic architecture in isolation of one another. Here, we use a combination of mathematical modelling and computer simulations to investigate how resource variation within and between habitats influences the way natural selection shapes phenotypic variation for a consumer trait and its genetic architecture. We show that when resources vary both within and between patches, the co-occurrence of divergent and frequency-dependent selection can lead to phenotypic polymorphism for many levels of gene flow, with the strongest consequences genetic architecture evolution when dispersal is either strong, or multiple phenotypic morphs are favoured within the same patch. |
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