May 18, 2012
New Study May Hold Clue To Proving The Gaia Theory
The Gaia Hypothesis proposes that the Earth is actually a giant living organism, and a University of Maryland (UMD) study might have found the key to unlocking this mystery, and this discovery could lead to an improved understanding of the climate and changes that occur within it. The key is sulfur, and researchers hope to find the relationships between the atmosphere, ocean organisms, and land, using sulfur in order to prove the Gaia Theory.
The Gaia Theory was first introduced in the 1970´s, by James Lovelock and Lynn Margulis. One of its first predictions held that the earth´s biological and physical processes coincide to produce an independent and fundamentally sentient system. The theory also presumes that sulfur made in the ocean should be stable enough against oxidation to move into the air. And either by the oxidation in the air or by the sulfur compound itself, it should eventually transfer to land. The most likely compound to accomplish this process would be dimethylsulfide.
Sulfur is part of numerous organic and inorganic compounds, and is the tenth most common element in the universe. Sulfur cycles through the land and living things, playing a vital part in health of the climate and its ecosystems, as well as living organisms.
The new study, published in this week´s Online Early Edition of the Proceedings of the National Academy of Sciences (PNAS), was authored by Harry Oduro of MIT, a UMD geologist named James Farquhar and Kathryn Van Alstyne, a marine biologist from Western Washington University. The three authors have created a tool that can trace and calculate the movements of the sulfur compound from ocean organisms, through the air, and finally to the land in order to verify or refute the Gaia Theory.
According to Oduro, who completed his PhD while conducting the study, and his associates, this study is the first to present direct calculations of the isotopic composition of dimethylsulfide and of its predecessor dimethylsulfoniopropionate. The measurements provide evidence of the changes between the isotope ratios of the two sulfur compounds that are produced bymacroalga and phytoplankton in the ocean. The calculations are significant because they are connected to the compounds´ metabolism by the ocean organisms, and they hold repercussions for tracing dimethylsulfide emission levels that occur when the compounds move from the ocean, to the air, and to the land.
Oduro stated, "Dimethylsulfide emissions play a role in climate regulation through transformation to aerosols that are thought to influence the earth's radiation balance.” He also said, "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."
"What Harry did in this research was to devise a way to isolate and measure the sulfur isotopic composition of these two sulfur compounds," Farquhar stated. He continued, “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.”
Sulfur, as with many chemical compounds, contains isotopes. The isotopes within an element are described as having a matching number of electrons and protons, but varying numbers of neutrons. Consequently, the isotopes are characterized by having the same chemical properties, with different nuclear and mass properties. These isotopic “signatures” make it possible for scientists to use exclusive combinations of an element´s radioactive isotopes to trace compounds of the element.
Farquhar concluded, "Harry's work establishes that we should expect to see variability in the sulfur isotope signatures of these compounds in the oceans under different environmental conditions and for different organisms. I think this will ultimately be very important for using isotopes to trace the cycling of these compounds in the surface oceans as well as the flux of dimethylsulfide to the atmosphere. The ability to do this could help us answer important climate questions, and ultimately better predict climate changes. And it may even help us to better trace connections between dimethylsulfide emissions and sulfate aerosols, ultimately testing a coupling in the Gaia hypothesis.”