Paper accepted by Journal of Fish Biology. Title, Authors, Abstract, Keywords here below. Code is here.
Eco-evolutionary dynamics induced by massive mortality events
Simone Vincenzi, Alain J Crivelli, William H Satterthwaite, Marc Mangel
Abstract: To explore the selective consequences of severe disturbance events, an eco-genetic model tuned on a population of marble trout Salmo marmoratus subject to periodic flood events was used to explore how the evolution of growth rates interacting with density-dependent processes can modify size-at-age and population structure, and in turn influence the resilience of populations. Fish with greater growth potential were assumed to have higher mortality rates. The results of simulations were compared between two scenarios, one in which populations may evolve growth rates and one in which the distribution of growth rates within a population is kept fixed. Evolving populations had greater proportion of age-1 individuals in the population, greater median length at age 3 (the typical age at sexual maturity for marble trout) and lower population sizes. The slightly smaller population sizes did not affect realized extinction risk. Resilience, defined as the number of years necessary to rebound from flood-induced population collapse, was on average from 2 to 3 years in both scenarios, with no significant difference between them. Moderate heritability of growth, relaxation of density-dependent processes at low densities and rapid recovery to a safe population size all combine to limit the capacity to evolve faster recovery after flood-induced population collapses via changing growth rates.
Keywords: Somatic growth; marble trout; trade-off; life histories; floods.