According to a new research study conducted by scientists from the University of California – Davis, animals and plants may not be in a position to adapt to climate change quickly enough.
The study looked at the tiny seashore animal copepod Tigriopus californicus, which is found from Alaska to Baja, California and live in tide pools on rocky outcrops high in the splash zone. UC Davis graduate student Morgan Kelly, the first author of the paper, collected copepods from eight locations between Oregon and Baja California in Mexico.
“This is a question a lot of scientists have been talking about,” said study co-author Eric Sanford, an associate professor of evolution and ecology at UC Davis and a researcher at the university’s Bodega Marine Laboratory. “Do organisms have the ability to adapt to climate change on a timescale of decades?”
Kelly grew the copepods in a lab for 10 generations, subjecting them to increased heat stress in an effort to select the more heat-tolerant animals. From the beginning, the copepods exhibited wide variability in heat tolerance no matter what location he gathered them from. But over the 10 generations Kelly was only able to coax approximately a half-degree Celsius of increased heat tolerance, and in most populations she had gathered, the heat tolerance had hit a plateau well before it reached even that.
In the wild, these copepods can withstand a temperature swing of 20 degrees Celsius a day, Kelly said. But they may be living at the edge of their tolerance, she said.
“It’s been assumed that widespread species have a lot of genetic capacity to work with, but this study shows that may not be so,” said co-author Rick Grosberg, professor of evolution and ecology at UC Davis. Many other species of animals, birds and plants face stress from climate change, and their habitats have also been fragmented by human activity — perhaps more than we realize, he said.
“The critical point is that many organisms are already at their environmental limits, and natural selection won’t necessarily rescue them,” Grosberg said.
Source: UC Davis