Stressful environments can indirectly select for increased longevity.

Area of Science:

• Evolutionary biology
• Genetics
• Gerontology

Background:

• Longevity is influenced by conserved genes in eukaryotes.
• Mutations extending lifespan often reduce fitness, hindering natural selection.
• Fitness consequences of longevity manipulation in varied environments are poorly understood.

Purpose of the Study:

• To investigate how environmental heterogeneity affects the evolution of longevity.
• To assess the fitness of long-lived mutants under stress conditions.
• To determine if environmental stress can drive the selection of longevity-associated alleles.

Main Methods:

• Laboratory selection experiments with Caenorhabditis elegans.
• Utilizing the age-1(hx546) mutant known for increased lifespan and stress resistance.
• Employing stochastic population projection models to simulate allele frequency changes.

Main Results:

• The age-1(hx546) mutant exhibited higher fitness than wild-type under periodic high-temperature stress.
• The mutant allele conferred a selective advantage when temperature stress coincided with variable food availability.
• Environmental heterogeneity, particularly stress, can alter allele frequencies over ecological time.

Conclusions:

• Environmental stress heterogeneity can indirectly promote the evolution of longevity.
• The study provides insights into the evolution of life-history strategies.
• Understanding these dynamics is crucial for gerontological and evolutionary research.