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- Crispo, Erika, et al.
(författare)
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The evolution of phenotypic plasticity in response to anthropogenic disturbance
- 2010
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Ingår i: Evolutionary Ecology Research. - Tucson, AZ, USA : Evolutionary Ecology Ltd. - 1522-0613 .- 1937-3791. ; 12:1, s. 47-66
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Tidskriftsartikel (refereegranskat)abstract
- Questions: Do evolutionary changes in phenotypic plasticity occur after anthropogenic disturbance? Do these changes tend to be increases or decreases in plasticity? How do these evolutionary patterns differ among taxa and trait types? Does evolution of plasticity change with time since the disturbance?Data incorporated: Evolutionary rates for plasticity estimated from 20 studies that have compared a plastic response in two or more populations, at least one of which had experienced an anthropogenic disturbance in nature and at least one of which had not.Method of analysis: We estimate evolutionary rates (darwins and haldanes) for plasticity for each study, which represent the amount of evolutionary change in plasticity. We then perform analyses of covariance, with the evolutionary rate numerator (amount of evolutionary change) as a response variable, taxa and trait type as predictor variables, and the amount of evolutionary time as a covariate.Conclusions:We find that plasticity has evolved in several cases, including both increases and decreases in the levels of plasticity following anthropogenic disturbances. The typical direction of this evolutionary response depends on an interaction between taxon and trait type. For instance, invertebrates sometimes show the evolution of increased plasticity for life-history traits, but the evolution of decreased plasticity for morphological traits. Plants, on the other hand, show no trends in the direction of plasticity evolution.
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| 2. |
- Thibert-Plante, Xavier, 1980-, et al.
(författare)
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When can ecological speciation be detected with neutral loci?
- 2010
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Ingår i: Molecular Ecology. - : Blackwell Publishing. - 0962-1083 .- 1365-294X. ; 19:11, s. 2301-2314
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Tidskriftsartikel (refereegranskat)abstract
- It is not yet clear under what conditions empirical studies can reliably detect progress toward ecological speciation through the analysis of allelic variation at neutral loci. We use a simulation approach to investigate the range of parameter space under which such detection is, and is not, likely. We specifically test for the conditions under which divergent natural selection can cause a ‘generalized barrier to gene flow’ that is present across the genome. Our individual-based numerical simulations focus on how population divergence at neutral loci varies in relation to recombination rate with a selected locus, divergent selection on that locus, migration rate and population size. We specifically test whether genetic differences at neutral markers are greater between populations in different environments than between populations in similar environments. We find that this expected signature of ecological speciation can be detected under part of the parameter space, most consistently when divergent selection is strong and migration is intermediate. By contrast, the expected signature of ecological speciation is not reliably detected when divergent selection is weak or migration is low or high. These findings provide insights into the strengths and weaknesses of using neutral markers to infer ecological speciation in natural systems.
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