Genomes <-> Geochemistry

Enormous advances in molecular biology make it possible, for the first time, to obtain entire genomes of organisms, and to begin the process of connecting genomes with geochemistry and evolution. Within the genomes of extremophiles are genes for enzymes that permit organisms to cope with an astonishing variety of geochemical environments. Almost nothing is known about the feedback mechanisms that translate geochemical challenges into genetic solutions. Nevertheless, a fundamental understanding of these connections could reveal much about the driving forces of evolution. At the same time, phylogenetic relations among organisms may permit the identification of the relative timing and types of environments where specific genes appeared. If biomarkers, isotopic fractionations, or trace element ratios can be associated with the development of specific genes, then the geologic record could revel the absolute timing of evolutionary developments at the genetic level. The potential for a new molecular level of paleontology, coupled with quantitative biogeochemical interpretations of how organisms obtain energy from geochemical processes could become a cornerstone for entirely novel efforts to integrate the history of life encoded in genomes with the history of the Earth encoded in the rocks.