Predicting patterns of long‐term adaptation and extinction with population genetics

@article{Bertram2017PredictingPO,
  title={Predicting patterns of long‐term adaptation and extinction with population genetics},
  author={Jason Bertram and Kevin Gomez and Joanna Masel},
  journal={Evolution},
  year={2017},
  volume={71}
}
Population genetics struggles to model extinction; standard models track the relative rather than absolute fitness of genotypes, while the exceptions describe only the short‐term transition from imminent doom to evolutionary rescue. But extinction can result from failure to adapt not only to catastrophes, but also to a backlog of environmental challenges. We model long‐term adaptation to long series of small challenges, where fitter populations reach higher population sizes. The population's… 
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9 Citations

An evolutionary tipping point in a changing environment
TLDR
It is shown how evolutionary tipping points produce evolutionary hysteresis, creating extinction debts, and there is no bound on the rate of evolution and persistence is determined by the critical rate of environmental change at which populations cease to grow.
Phenotypic plasticity can facilitate evolutionary rescue
TLDR
It is found that the probability of population persistence depends non-monotonically on the degree of phenotypic heritability between generations: some heritability can help avert extinction, but too much heritability removes any benefit of Phenotypic plasticity.
A lottery model of density-dependent selection in evolutionary genetics
TLDR
A new model of density-dependent selection is developed by generalizing the fixed-density classic lottery model of territorial acquisition to accommodate arbitrary population densities and it is shown that, with density dependence, co-existence is possible in the lottery model in a stable environment.
Density-dependent selection and the limits of relative fitness
TLDR
It is found that density-independent relative fitnesses accurately describe strong selection acting on any one trait, even fecundity, which is both density-regulating and subject to density-dependent selection.
Density-dependent selection and the limits of relative fitness.
Haldane’s cost of selection imposes a mild constraint on adaptation, with a high proportion of deaths in A. thaliana being selective
TLDR
This work distinguishes different lines of reasoning that lead to speed limits, including one line of reasoning which has not yet been fully addressed, and estimates highly permissive limits to the speed of adaptation in all environmental conditions.
Mutation bias can shape adaptation in large asexual populations experiencing clonal interference
TLDR
This work considers the behavior of two simultaneously adapting traits, one with larger mutation rate U, the other with larger selection coefficient s, using asexual traveling wave models and finds that adaptation is dominated by whichever trait has the faster rate of adaptation v in isolation, with the other trait subject to evolutionary stalling.
Evolutionary Rescue Through Partly Heritable Phenotypic Variability
TLDR
It is found that the probability of population persistence depends nonmonotonically on the degree of phenotypic heritability between generations: some heritability can help avert extinction, but too much heritability removes any benefit of Phenotypic variability.
How to Make a Rodent Giant: Genomic Basis and Tradeoffs of Gigantism in the Capybara, the World’s Largest Rodent
TLDR
It is hypothesized that gigantism in the capybara likely involved three evolutionary steps: increase in body size by cell proliferation through the ISS pathway, coupled evolution of growth-regulatory and cancer-suppression mechanisms, possibly driven by intragenomic conflict, and establishment of the T cell-mediated tumor suppression pathway as an anticancer adaptation.

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