RT Journal Article
SR Electronic
T1 Density-dependent natural selection mediates harvest-induced trait changes
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 561522
DO 10.1101/561522
A1 Alix Bouffet-Halle
A1 Jacques Mériguet
A1 David Carmignac
A1 Simon Agostini
A1 Alexis Millot
A1 Samuel Perret
A1 Eric Motard
A1 Beatriz Decenciere
A1 Eric Edeline
YR 2020
UL http://biorxiv.org/content/early/2020/08/10/561522.abstract
AB Rapid life-history changes caused by size-selective harvesting are often interpreted as a response to direct harvest selection against a large body size. However, similar trait changes may result from a harvest-induced relaxation of natural selection for a large body size via density-dependent selection. Here, we show evidence of such density-dependent selection favouring large-bodied individuals at high population densities, in replicated pond populations of medaka fish. Harvesting, in contrast, selected medaka directly against large-bodied medaka and, in parallel, decreased medaka population densities. Five years of harvesting were enough for harvested and unharvested medaka populations to inherit the classically-predicted trait differences, whereby harvested medaka grew slower and matured earlier than unharvested medaka. We demonstrate that this life-history divergence was not driven by direct harvest selection for a smaller body size in harvested populations, but by density-dependent natural selection for a larger body size in unharvested populations.Competing Interest StatementThe authors have declared no competing interest.