Animals have been growing smaller bodies, but is a warming climate to blame?
Embargoed until:
Publicly released:
2019-07-24 09:01
Are animals growing smaller bodies because of global warming? No, according to Australian and International researchers who set out to determine if natural selection is causing animals to grow smaller bodies due to warming global temperatures. The team analysed data from databases covering the last 50 years on wild populations. They found natural selection consistently favoured larger animals over smaller ones, regardless of temperature change, suggesting that the smaller body sizes being seen in some animals is not an adaptation to warming climates.
Journal/conference: Royal Society Proceedings B
Link to research (DOI): 10.1098/rspb.2019.1332
Organisation/s: The Australian National University
Funder: A.M.S. was supported by NSF (DEB1748945). K.D.W. was supported by NSF (DEB1257965). A NESCent working group supported the development of the databases used in this analysis (NSF grant EF-0905606).
Media Release
From: The Royal Society
No evidence that warmer temperatures are associated with selection for smaller body sizes
Proceedings of the Royal Society B: Biological Sciences
Shrinking body size in animals has been considered a general response to global warming, much like changes in species’ distributions and phenology. These declines in body size are often thought to represent an adaptive evolutionary response to natural selection imposed by warming temperatures. We combined multiple studies of natural selection in wild animal populations over the past 50 years and found that selection does not favor smaller animal body sizes as temperatures have warmed. Instead, selection consistently favored larger animals, but was unrelated to temperature. These results suggest little evidence that declines in body size represent an adaptive evolutionary response to a warming climate.
