UM postdoc fellow takes advantage of cold snap to study natural selection in lizards
MISSOULA – Research by University of Montana postdoctoral fellow Shane Campbell-Staton appears in the latest issue of the journal Science.
Campbell-Staton, a National Science Foundation Postdoctoral Fellow, was the lead author of a report titled "Winter storms drives rapid phenotypic, regulatory and genomic shifts in the green anole lizard." His research focused on the effects of natural selection in green anole lizards after an extreme cold weather event in the southeastern United States during the winter of 2013-14.
The study was unique, Campbell-Staton said, because the unpredictable nature of extreme weather events makes it difficult to study natural selection responses to such events.
"Unless you happen to have data before such an event and can get data directly after, it can be very difficult to test hypotheses about their impacts," Campbell-Staton said. "Our study is unique in that we had data before and after this extreme weather event, and we were able to measure selection at three levels: whole animal function, gene expression and genetic variation. These data give us a very detailed look at how extreme events affect populations in the wild."
The study found significant increases in cold tolerance at the species' southern limit. Gene expression in southern survivors shifted toward patterns characteristic of northern populations.
"We conclude that extreme winter events can rapidly produce strong shifts in natural populations at multiple biological levels," he said. "The fact that we saw such a strong shift in the southern population, in their function, gene expression and allele frequencies, within the course of a single calendar year was quite surprising."
Campbell-Staton said the research raises larger questions about the long-term consequences of extreme weather events for these populations.
"When most people think about climate change, they think about the gradual warming our planet is undergoing," Campbell-Staton said.
"However another major symptom of modern climate change is the increase in frequency and magnitude of extreme weather events like cold snaps, heat waves, droughts, etc. Although brief in nature, these types of events can have profound effects on natural populations for many generations.
"We know that selection occurs at a cost: death," he said. "It's possible that the individuals that died as a result of this cold snap may have had the genetic and physiological tools to survive a drought or a heat wave, and now those lineages are lost. We still have a lot to learn about how predicted patterns of extreme weather will impact biodiversity."
Find the article online at http://science.sciencemag.org/content/357/6350/495.