Open AccessStressful environments can indirectly select for increased longevity
Author(s) -
Savory Fiona R.,
Benton Timothy G.,
Varma Varun,
Hope Ian A.,
Sait Steven M.
Publication year - 2014
Publication title -
ecology and evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.17
H-Index - 63
ISSN - 2045-7758
DOI - 10.1002/ece3.1013
Subject(s) - longevity , biology , caenorhabditis elegans , allele , natural selection , evolutionary biology , genetics , selection (genetic algorithm) , balancing selection , population , genetic fitness , range (aeronautics) , ecology , gene , demography , artificial intelligence , sociology , computer science , materials science , composite material
Abstract Longevity is modulated by a range of conserved genes in eukaryotes, but it is unclear how variation in these genes contributes to the evolution of longevity in nature. Mutations that increase life span in model organisms typically induce trade‐offs which lead to a net reduction in fitness, suggesting that such mutations are unlikely to become established in natural populations. However, the fitness consequences of manipulating longevity have rarely been assessed in heterogeneous environments, in which stressful conditions are encountered. Using laboratory selection experiments, we demonstrate that long‐lived, stress‐resistant C aenorhabditis elegans age‐1(hx546) mutants have higher fitness than the wild‐type genotype if mixed genotype populations are periodically exposed to high temperatures when food is not limited. We further establish, using stochastic population projection models, that the age‐1(hx546) mutant allele can confer a selective advantage if temperature stress is encountered when food availability also varies over time. Our results indicate that heterogeneity in environmental stress may lead to altered allele frequencies over ecological timescales and indirectly drive the evolution of longevity. This has important implications for understanding the evolution of life‐history strategies.