RELATIONSHIPS BETWEEN GENETIC VARIABILITY AND LIFE-HISTORY FEATURES OF BONY FISHES

Area of Science:

• Evolutionary Biology
• Ichthyology
• Population Genetics

Background:

• Genetic variation is a key driver of adaptation.
• Life-history traits and environmental factors are hypothesized to influence genetic variation.

Purpose of the Study:

• To test the relationship between genetic variation and life-history variables in bony fishes.
• To investigate the roles of balancing selection (fecundity) and environmental variation (population growth capacity) in shaping genetic diversity.

Main Methods:

• Compiled genetic data from existing literature for 80 bony fish species.
• Extracted or estimated life-history variables including longevity, age at maturity, egg size, body size, and lifetime fecundity.
• Analyzed correlations between average heterozygosity and life-history/environmental variables.

Main Results:

• Average heterozygosity did not significantly correlate with fecundity.
• Heterozygosity showed significant associations with shorter generation times, earlier maturation, smaller body size, and smaller egg size.
• These traits align with a demographic strategy maximizing the intrinsic rate of population increase.

Conclusions:

• Genetic variation in bony fishes is predominantly influenced by environmental variation, not solely by the opportunity for balancing selection via fecundity.
• Species with higher heterozygosity are adapted to less stable environments, prioritizing rapid population growth.