Diminishing-returns epistasis decreases adaptability along an evolutionary trajectory

Wünsche, Andrea; Dinh, Duy M.; Satterwhite, Rebecca Sue; Arenas, Carolina Díaz; Stoebel, Daniel M.; Cooper, Tim F.

doi:10.1038/s41559-016-0061

Cited by 103 publications

(107 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…With epistasis, mutation sub-stitutions that are deleterious in one genetic context may even be necessary in another context for a population to reach the global peak. This dependence predicts a rugged landscape, although an experimental test did not support this prediction (Wünsche et al 2017). In almost all alternative environments, however, the relevant intermediate steps become beneficial.…”

Section: Discussionmentioning

confidence: 97%

“…Theoretical models predict that later substituting mutations will often depend on earlier mutations for their benefit (Draghi and Plotkin 2013;Blanquart et al 2014). This dependence predicts a rugged landscape, although an experimental test did not support this prediction (Wünsche et al 2017). By contrast, when mutations that are selected together in one environment are then tested in another, they seem more likely to act independently.…”

mentioning

confidence: 94%

See 1 more Smart Citation

Environment changes epistasis to alter trade‐offs along alternative evolutionary paths

et al. 2019

Self Cite

View full text Add to dashboard Cite

The fitness effect of a mutation can depend on both its genetic background, known as epistasis, and the prevailing external environment. Many examples of these dependencies are known, but few studies consider both aspects in combination, especially as they affect mutations that have been selected together. We examine interactions between five coevolved mutations in eight diverse environments. We find that mutations are, on average, beneficial across environments, but that there is high variation in their fitness effects, including many examples of mutations conferring a cost in some, but not other, genetic background‐environment combinations. Indeed, even when global interaction trends are accounted for, specific local mutation interactions are common and differed across environments. One consequence of this dependence is that the range of trade‐offs in genotype fitness across selected and alternative environments are contingent on the particular evolutionary path followed over the mutation landscape. Finally, although specific interactions were common, there was a consistent pattern of diminishing returns epistasis whereby mutation effects were less beneficial when added to genotypes of higher fitness. Our results underline that specific mutation effects are highly dependent on the combination of genetic and external environments, and support a general relationship between a genotype's current fitness and its potential to increase in fitness.

show abstract

Section: Discussionmentioning

confidence: 97%

mentioning

confidence: 94%

Environment changes epistasis to alter trade‐offs along alternative evolutionary paths

et al. 2019

Self Cite

View full text Add to dashboard Cite

show abstract

“…As a consequence of these mutations, specific pathways of TRN, which are irrelevant to the present selection pressure, are inactivated (48). However, the fitness benefit of these TF mutations decline over time, likely as a consequence of diminishing returns epistasis (49), and as adaptation decelerates, selective constraints play a bigger role in the mutation frequency. In a well adapted population, the optimal variants of TFs are maintained by purifying selection.…”

Section: Discussionmentioning

confidence: 99%

Dynamics of genetic variation in Transcription Factors and its implications for the evolution of regulatory networks in Bacteria

Ali

Seshasayee

2019

Preprint

View full text Add to dashboard Cite

The evolution of bacterial regulatory networks has largely been explained at macroevolutionary scales through lateral gene transfer and gene duplication. Transcription factors (TF) have been found to be less conserved across species than their target genes (TG). This would be expected if TFs accumulate mutations faster than TGs. This hypothesis is supported by several lab evolution studies which found TFs, especially global regulators, to be frequently mutated. Despite these studies, the contribution of point mutations in TFs to the evolution of regulatory network is poorly understood. We tested if TFs show greater genetic variation than their TGs using whole-genome sequencing data from a large collection of E coli isolates. We found TFs to be less diverse, across natural isolates, due to their regulatory roles. TFs were enriched in mutations in multiple adaptive lab evolution studies but not in mutation accumulation. However, over long-term evolution, relative frequency of mutations in TFs showed a gradual decay after a rapid initial burst. Our results suggest that point mutations, conferring large-scale expression changes, may drive the early stages of adaptation but gene regulation is subjected to stronger purifying selection post adaptation.

show abstract

“…Applying the results of this experiment to natural phytoplankton population requires taking into account how population size and diversity (among other factors, such as recombination rates) affect adaptation (53). Previous work has shown that higher standing genetic variation can allow adapting populations to evolve faster (54)(55)(56)(57). Similarly, recombination and plasticity (1, 58) can both speed up adaptation (59).…”

Section: Discussionmentioning

confidence: 99%

Evolutionary consequences of multidriver environmental change in an aquatic primary producer

Brennan

Colegrave

Collins

2017

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Climate change is altering aquatic environments in a complex way, and simultaneous shifts in many properties will drive evolutionary responses in primary producers at the base of both freshwater and marine ecosystems. So far, evolutionary studies have shown how changes in environmental drivers, either alone or in pairs, affect the evolution of growth and other traits in primary producers. Here, we evolve a primary producer in 96 unique environments with different combinations of between one and eight environmental drivers to understand how evolutionary responses to environmental change depend on the identity and number of drivers. Even in multidriver environments, only a few dominant drivers explain most of the evolutionary changes in population growth rates. Most populations converge on the same growth rate by the end of the evolution experiment. However, populations adapt more when these dominant drivers occur in the presence of other drivers. This is due to an increase in the intensity of selection in environments with more drivers, which are more likely to include dominant drivers. Concurrently, many of the trait changes that occur during the initial short-term response to both single and multidriver environmental change revert after about 450 generations of evolution. In future aquatic environments, populations will encounter differing combinations of drivers and intensities of selection, which will alter the adaptive potential of primary producers. Accurately gauging the intensity of selection on key primary producers will help in predicting population size and trait evolution at the base of aquatic food webs.

show abstract

Diminishing-returns epistasis decreases adaptability along an evolutionary trajectory

Cited by 103 publications

References 29 publications

Environment changes epistasis to alter trade‐offs along alternative evolutionary paths

Environment changes epistasis to alter trade‐offs along alternative evolutionary paths

Dynamics of genetic variation in Transcription Factors and its implications for the evolution of regulatory networks in Bacteria

Evolutionary consequences of multidriver environmental change in an aquatic primary producer

Contact Info

Product

Resources

About