"Interpreting Geochemical Biomarkers in the Light of Genomics"

David Gold (Caltech)
Wednesday, November 15, 4:00pm to 5:00pm

Biological compounds preserved in rocks can function as biomarkers, providing insight into long-extinct organisms. Because scientists understand many of the biological pathways necessary to synthesize biomarkers, the genetic and geochemical records can be used to inform each other, and improve our understanding of these “molecular fossils.” In this talk, I will focus on one class of biomarkers (the steranes) and consider what we do and don’t understand about these compounds in light of biological data. In some cases, molecular clock analyses have lined up well with the biomarker record, confirming our expectations, but in other cases the two lines of data are in conflict. When biomarkers are considered within a phylogenetic (evolutionary) framework, I suggest that there is a lot of uncertainty remaining in the interpretation of steranes. I will conclude by offering several areas of research that should help distinguish between current competing hypotheses about the biomarker record and the evolution of complex life.

About the Series

EAPS interdisciplinary Department Lecture Series (DLS) brings both national and international speakers into the department to share their work. In addition EAPS sponsors a number of annual flagship named lectures, among them the Brace Lecture, the Kendall Lecture, and the Carlson Lecture. All such lectures and seminars are free and open to the public. To be added to EAPS event listserve contact Brandon Milardo, bmilardo@mit.edu.