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Heterosis counteracts hybrid breakdown to forestall speciation by parallel natural selection.
Thompson, Ken A; Schluter, Dolph.
Afiliação
  • Thompson KA; Department of Zoology and Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada.
  • Schluter D; Department of Zoology and Biodiversity Research Centre, University of British Columbia, Vancouver, British Columbia, Canada.
Proc Biol Sci ; 289(1974): 20220422, 2022 05 11.
Article em En | MEDLINE | ID: mdl-35506223
In contrast to ecological speciation, where reproductive isolation evolves as a consequence of divergent natural selection, speciation by parallel natural selection has been less thoroughly studied. To test whether parallel evolution drives speciation, we leveraged the repeated evolution of benthic and limnetic ecotypes of threespine stickleback fish and estimated fitness for pure crosses and within-ecotype hybrids in semi-natural ponds and in laboratory aquaria. In ponds, we detected hybrid breakdown in both ecotypes but this was counterbalanced by heterosis and the strength of post-zygotic isolation was nil. In aquaria, we detected heterosis in limnetic crosses and breakdown in benthic crosses, which is suggestive of process- and ecotype-specific environment-dependence. In ponds, heterosis and breakdown were three times greater in limnetic crosses than in benthic crosses, contrasting the prediction that the fitness consequences of hybridization should be greater in crosses among more derived ecotypes. Consistent with a primary role for stochastic processes, patterns differed among crosses between populations from different lakes. Yet, the observation of qualitatively similar patterns of heterosis and hybrid breakdown for both ecotypes when averaging the lake pairs indicates that the outcome of hybridization is repeatable in a general sense.
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Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Smegmamorpha / Vigor Híbrido Tipo de estudo: Prognostic_studies Limite: Animals Idioma: En Revista: Proc Biol Sci Assunto da revista: BIOLOGIA Ano de publicação: 2022 Tipo de documento: Article País de afiliação: Canadá

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Smegmamorpha / Vigor Híbrido Tipo de estudo: Prognostic_studies Limite: Animals Idioma: En Revista: Proc Biol Sci Assunto da revista: BIOLOGIA Ano de publicação: 2022 Tipo de documento: Article País de afiliação: Canadá
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