Scientists plot shell growth atom by atom
DAVIS, Calif., Oct. 24 (UPI) — Scientists have modeled the growth of shells with unprecedented detail. For the first time, researchers have explained how the shells of tiny marine organisms are assembled atom by atom.
The discovery will help scientists render insights into the history of the climate — clues left behind by ancient shelled creatures.
“We’ve gotten the first glimpse of the biological event horizon,” Howard Spero, a geochemist at the University of California, Davis, said in a news release.
The research offers a step-by-step map for how biology and proper chemical conditions come together to trigger calcium carbonate biomineralization. The how-to guide highlights the importance of sodium and magnesium, two chemicals found in a shell’s organic layer, but not previously thought to be of importance to shell formation.
The breakthrough in shell formation — detailed in the journal PNAS — is important because it allows scientists to better understand how environmental conditions are reflected in the growth of a shell. Impurities are a product of the shell’s environmental surroundings and the nature of its construction. If scientists don’t understand how it’s constructed, it’s hard to make predictions about the environmental surroundings.
Now, scientists will be able to make more accurate predictions about what the ancient ocean looked like, and when.
“Finding out how much magnesium there is in a shell can allow us to find out the temperature of seawater going back up to 150 million years,” lead study author Oscar Branson said.
But magnesium levels can vary from layer to layer within a shell’s structure. Each layer or band reflects a day of shell growth.
“We know that shell formation processes are important for shell chemistry, but we don’t know much about these processes or how they might have changed through time,” Branson explained. “This adds considerable uncertainty to climate reconstructions.”
The latest research promises to relieve some of that uncertainty.