Genetic variance in fitness indicates rapid contemporary adaptive evolution in wild animals
Timothée Bonnet, Michael B. Morrissey, Pierre de Villemereuil, Susan C. Alberts, Peter Arcese, Liam D. Bailey, Stan Boutin, Patricia Brekke, Lauren J. N. Brent, Glauco Camenisch, Anne Charmantier, Tim Clutton‐Brock, Andrew Cockburn, David W. Coltman, Alexandre Courtiol, Eve Davidian, Simon Evans, John G. Ewen, Marco Festa‐Bianchet, Christophe de Franceschi, Lars Gustafsson, Oliver P. Höner, Thomas M. Houslay, Lukas F. Keller, Marta B. Manser, Andrew G. McAdam, Emily M. McLean, Pirmin Nietlisbach, Helen L. Osmond, Josephine M. Pemberton, Erik Postma, Jane M. Reid, Alexis Rutschmann, Anna W. Santure, Ben C. Sheldon, Jon Slate, Céline Teplitsky, Marcel E. Visser, Bettina Wachter, Loeske E. B. Kruuk
Abstract
The rate of adaptive evolution, the contribution of selection to genetic changes that increase mean fitness, is determined by the additive genetic variance in individual relative fitness. To date, there are few robust estimates of this parameter for natural populations, and it is therefore unclear whether adaptive evolution can play a meaningful role in short-term population dynamics. We developed and applied quantitative genetic methods to long-term datasets from 19 wild bird and mammal populations and found that, while estimates vary between populations, additive genetic variance in relative fitness is often substantial and, on average, twice that of previous estimates. We show that these rates of contemporary adaptive evolution can affect population dynamics and hence that natural selection has the potential to partly mitigate effects of current environmental change.