14 DAY TRIAL // Investigators from the University of Maryland (UMD), in the United States, say that a new study they conducted provided new evidence that supports the Gaia hypothesis. This one proposes that the entire planet is a giant, living organism.
The team believes that it will soon be able to discover and analyze a large number of previously hidden interactions between the atmosphere, land and organisms living in Earth's oceans, which may be interpreted as providing support for this theory.
Scientists James Lovelock and Lynn Margulis were the first proponents of the Gaia hypothesis, back in the 1970s. At the time, they suggested that all biological and physical processes going on on the planet are linked to each other by unbreakable bonds, making the Earth a self-regulating system.
When the theory was first proposed, the investigators suggested that a sulfur compound – most likely dimethylsulfide – must be produced by marine organisms in a stable configuration, so that it could be transferred into the atmosphere, and then deposited on land.
This proposed sulfur cycle has since been considered a make-it-or-break-it piece of evidence for the Gaia hypothesis. What the UMD team has recently managed was to create a tracking and measurement tool destined specifically to follow sulfur throughout the aforementioned environments.
Details of how the tool works were published in the May 14 early online issue of the esteemed journal Proceedings of the National Academy of Sciences (PNAS). UMD expert Harry Oduro was the first author of the paper.
UMD geochemist James Farquhar and marine biologist Kathryn Van Alstyne, who is based at the Western Washington University (WWU) were also a part of the research group. They say that sulfur is the tenth most abundant chemical element in the Universe.
The tool the team developed is capable of measuring the isotopic composition of dimethylsulfide and of its precursor dimethylsulfoniopropionate directly. “Dimethylsulfide emissions play a role in climate regulation through transformation to aerosols that are thought to influence the earth's radiation balance,” Oduro says.
“We show that differences in isotopic composition of dimethylsulfide may vary in ways that will help us to refine estimates of its emission into the atmosphere and of its cycling in the oceans,” he adds.
“What Harry did in this research was to devise a way to isolate and measure the sulfur isotopic composition of these two sulfur compounds,” explains Farquhar, who holds an appointment as a professor with the UMD Department of Geology.
“This was a very difficult measurement to do right, and his measurements revealed an unexpected variability in an isotopic signal that appears to be related to the way the sulfur is metabolized,” he adds.