Certain marine species could adapt quickly to climate change by tinkering with their genes.
Recent research from the southern Gulf of St. Lawrence off the Labrador Peninsula found that the types of winter skate—a flat, cartilaginous species of fish—were changing their body structure to better suit the area’s warmer waters. But they weren’t evolving. Instead, they were simply switching which genes they chose to “turn on.”
“This is evidence that species can adapt over relatively short periods of time in the evolutionary context,” said Paul Bentzen, a professor with Dalhousie University’s biology department. “In some cases, not by changing their DNA sequence but simply by changing how they express their genes.”
This form of adaptation is caused by what researchers cause “epigenetic changes,” and it’s different from the normal process of evolution. Bentzen said the researchers’ attention was first drawn to the southern Gulf of St. Lawrence because of the peculiarities of the winter skate there. While the species is found all along the North American coast, this particular population was much smaller in size than its counterparts in the rest of the Atlantic Ocean. The researchers hypothesized that this could be because the waters in the gulf tend to be much warmer due to their shallower depth.
They found that while this was in fact the case, the species didn’t really display any evolutionary changes. Evolution generally involves changes in the actual composition of a species’ DNA, which occur between generations and at a fairly low rate, according to Jackie Lighten, with the University of East Anglia’s School of Environmental Sciences in the United Kingdom.
“On the other hand, changes in gene expression do not rely on these slow changes to the DNA. This process describes switching on or off parts of the DNA that have specific functions. These can also be turned up or turned down so that their function becomes stronger or weaker,” he said.
Unlike evolution, this process is extremely quick—it can sometimes take place in just a matter of days—which means that certain species could be better equipped to deal with rapid changes in climate. This is particularly the case for species that have a longer life span and lower reproductive rates, like the skate.
The researchers hope that their findings could have implications in the conservation field and help shape policy that would protect endangered species. The winter skate is part of this list, in part because there has been a lot of momentum toward increasing the numbers of gray seals in the southern Gulf of St. Lawrence.
“People tend to care more about a cute, fluffy seal pup than a strange-looking fish on the ocean floor. The sad thing is that this fish, and potentially others, in the southern Gulf of St. Lawrence could provide real insight into how future climate change may affect marine biodiversity, and just as we are becoming to realize this, they may not be around for much longer,” said Lighten.
However, Bentzen warned against overestimating the ability of different species to adapt because there are still unanswered questions as to how rapidly the changes occur. The skate in the southern Gulf of St. Lawrence has been in that habitat for around 7,000 years, or around 318 generations given its life span.
“That’s a long time in terms of the rate of environmental change we’re seeing today,” he said.
The researchers intend to continue working to plug gaps in their knowledge, including carrying out more experimental work in the laboratory and focusing on individual animals to get a closer understanding of how they adapt.
“There is lots of scope to investigate similar scenarios in other species, too. For instance, we see similar adaptations in a flat fish that occupies a similar oceanographic range, and other evidence leads us to suspect that this may also be due to regulation of gene expression in response to warmer waters,” said Lighten.
Reprinted from ClimateWire with permission from Environment & Energy Publishing, LLC. E&E provides daily coverage of essential energy and environmental news at www.eenews.net. Click here for the original story.