We acknowledge financial support from the Ministerio de Ciencia e Innovación, Spain (grant CGL2010-15395 to MS, JCI-2010-06156 fellowship to LEC, and grant BFU2009-07564 to ELR); from Generalitat de Catalunya (grant 2009SGR 636 to MS); and from the ICREA Acadèmia program.
Keeping pace with climate change: what is wrong with the evolutionary potential of upper thermal limits?
Article first published online: 13 OCT 2012
© 2012 The Authors. Ecology and Evolution published by Blackwell Publishing Ltd.
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Ecology and Evolution
Volume 2, Issue 11, pages 2866–2880, November 2012
How to Cite
Ecology and Evolution 2012; 2(11): 2866–2880
- Issue published online: 8 NOV 2012
- Article first published online: 13 OCT 2012
- Manuscript Accepted: 27 AUG 2012
- Manuscript Revised: 20 AUG 2012
- Manuscript Received: 20 JUL 2012
- Ministerio de Ciencia e Innovación
- ICREA. Grant Number: JCI-2010-06156
- Ramón y Cajal contract. Grant Numbers: BFU2009-07564, 2009SGR 636
- Generalitat de Catalunya
- heating rate;
- knockdown resistance;
- metabolic rate;
- selection responses;
The potential of populations to evolve in response to ongoing climate change is partly conditioned by the presence of heritable genetic variation in relevant physiological traits. Recent research suggests that Drosophila melanogaster exhibits negligible heritability, hence little evolutionary potential in heat tolerance when measured under slow heating rates that presumably mimic conditions in nature. Here, we study the effects of directional selection for increased heat tolerance using Drosophila as a model system. We combine a physiological model to simulate thermal tolerance assays with multilocus models for quantitative traits. Our simulations show that, whereas the evolutionary response of the genetically determined upper thermal limit (CTmax) is independent of methodological context, the response in knockdown temperatures varies with measurement protocol and is substantially (up to 50%) lower than for CTmax. Realized heritabilities of knockdown temperature may grossly underestimate the true heritability of CTmax. For instance, assuming that the true heritability of CTmax in the base population is h2 = 0.25, realized heritabilities of knockdown temperature are around 0.08–0.16 depending on heating rate. These effects are higher in slow heating assays, suggesting that flawed methodology might explain the apparently limited evolutionary potential of cosmopolitan D. melanogaster.