Primordial Sulfur and the Origin of Life

Abstract

Sulfur is one of the essential elements of life; therefore life as we know it would not be possible had sulfur not been present in the prebiotic broth on the ancient Earth. One of the prevailing theories for the origin of life posits that S2- was the primordial energy source for life. The S2- could have been formed either by low energy chemical processes in hot water on planets or by high energy photolytic processes in interstellar space. The goal of this project is to determine which of these two processes created the fundamental form of sulfur necessary for the creation of life. This project entails the separation, isolation, and determination of the isotope ratios for indigenous sulfur-bearing species in carbonaceous meteorites. The Physical Sciences department houses the MacEwan Meteorite collection, which includes several carbonaceous chondrites. To carry out this project we will use methods developed in our department by the CHEM 498 student Amanda Coyle to extract the sulfide from the previously mentioned carbonaceous chondrites. These extracts will then be analyzed to quantify the amount of sulfide in each stone. Then, through collaboration with Dr. Farquhar, a professor of Geology at the University of Maryland, we will determine the ratios for all of the sulfur isotopes in the stones using his state-of-the-art instrument. This project will make new contributions to the understanding of how prebiotic sulfur arose during the first billion years of the solar system’s existence and how it potentially led to life on Earth.

Faculty Mentor: Robert Hilts

Department: Chemistry