August 11, 2016
Researchers in the Department of
Earth Sciences have shown that high-latitude bivalves live longer and grow
slower than those in the tropics. Their findings are the subject of an article
in the "Proceedings of the Royal Society B" (The Royal Society,
2016).
David Moss, a Ph.D. student in
the Earth sciences department, located in the College of Arts and Sciences, is
the article's lead author.
"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,"
he says, referring to animals such as oysters, clams, scallops and mussels.
"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."
After months of work by Moss and
other members of the Earth sciences department, two patterns have emerged. The
first reveals that, as a bivalve's lifespan increases, its growth rate
decreases. The second shows that long life and slow growth are common among
animals near the North and South poles, whereas tropical bivalves, close to the
equator, are fast-growing and short-lived.
"As the poles are thought to
harbor ecosystems like those from millions of years ago, our data suggest that
more ancient animals were slow-growing," Moss says.
Professor Linda Ivany '88, in
whose lab Moss is based, says bivalves are just as abundant in the fossil
record as they are in today's oceans. As a result, she and her students can
easily recover bivalve lifespans and growth rates by studying the bands in
their fossilized shells, a process analogous to tree-ring dating.
Ivany says this kind of work has
implications for the study of the evolutionary history of life on Earth, and
may help explain why the metabolism of cold-blooded animals has changed over
time.
"Research shows that marine
animals have gotten bigger over the last 500 million years," Ivany says.
"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."
Posts
No comments:
Post a Comment
You only need to enter your comment once! Comments will appear once they have been moderated. This is so as to stop the would-be comedian who has been spamming the comments here with inane and often offensive remarks. You know who you are!