Changes in precipitation patterns influence natural selection at global scale
What matters more for the evolution of plants and animals, precipitation or temperature? Scientists have found a surprising answer: rain and snow may play a more important role than how hot or cold it is.
|Red deer on Scotland's Isle of Rum, where scientists are studying precipitation change effects |
[Credit: Sean Morris]
Twenty scientists from the United States, Canada, Europe and Australia contributed to the study. Their results were published in the journal Science.
The team assembled a database of 168 published studies that measured natural selection over certain time periods for plant and animal populations worldwide. The results from the data set the scientists examined showed that between 20 and 40 percent of genetic changes could be attributed to variability in local precipitation.
|Medium ground finch in the Galapagos, site of a study of climate and natural selection |
[Credit: Andrew Hendry]
That's significant, he says, "especially considering the global scale of the study. These results suggest that variation in selection is actually partly predictable based on climate features like precipitation."
Adds Doug Levey, program director in NSF's Division of Environmental Biology, "These results show that changes in precipitation can have surprising evolutionary effects on plants and animals worldwide."
|Soay sheep in driving rain in the St. Kilda Archipelago in Scotland, a research site in the study |
[Credit: Owen Jones]
"Differences in precipitation over years have affected the sizes of seeds available for the birds to eat," Siepielski said. "Birds that had bills well-matched to eat particular seed sizes were the ones that tended to survive."
The team found that changes in temperature had much less effect than precipitation. Siepielski called that surprising. "Temperature didn't have much explanatory power," he said. "It might act on a different scale that we couldn't pick up in the data set."
|Blue-tailed damselfly in Sweden, where a long-term precipitation study has been conducted |
[Credit: Erik Svensson]
Translation: what comes down as rain or snow may radically alter how some species will evolve.
Author: Cheryl Dybas | Source: National Science Foundation [March 03, 2017]