Clams and other bivalves living near the poles have longer lifespan than their peers positioned closer to the equator. Photo by Sylvia sooyoN/Shutterstock
SYRACUSE, N.Y., Aug. 11 (UPI) -- Want to live longer? Live closer to the poles. At least that's the strategy employed by bivalves like oysters, clams, scallops and mussels.
In a recent study published in Proceedings of the Royal Society B, researchers revealed bivalves living closer to the North and South pole grow slower and live longer than their peers closer to the tropics.
"We've created a global database of more than 1,100 populations of marine bivalves, documenting their maximum reported lifespan and growth rate, along with body size," David Moss, an Earth scientist at Syracuse University, said in a news release. "Cold-blooded marine animals, such as bivalves, are influenced by their environment, so latitudinal patterns that exist in bivalves likely exist in other invertebrates, too."
Scientists believe polar ecosystems look and behave similar to ancient ecosystems, which suggests Earth's earliest creatures also opted for a slow-growth strategy.
Linda Ivany, fellow researcher and Syracuse professor, thinks the findings set scientists on a course for explaining the changes in size and metabolism measured among modern marine animals.
"Research shows that marine animals have gotten bigger over the last 500 million years," Ivany explained. "Because body size is determined by how fast you grow and how long you grow, this work sets the stage for us to move back in time and answer evolutionary questions about why and how animals have gotten bigger."
In addition to further exploring the link between growth and size over the last 540 million years, Ivany and Moss also hope to explain the correlation between growth strategy and speciation. Biodiversity is greater closer to the tropics than the poles.
"Short generation times and high mutation rates associated with short lifespan and fast growth enable new species to appear at a faster rate in the tropics," Moss added. "The distribution of lifespan and growth with latitude might help explain one of the more fundamental patterns in the evolutionary and ecological history of animal life on the planet: the latitudinal diversity gradient."