J. Peter Gogarten

University of Connecticut, Biology/Physics Building Rooms 404/426/427 Unit 3125, 91 North Eagleville Road, Storrs CT 06269-3125, USA.
gogarten@uconn.edu

Peter Gogarten and his collaborators develop and use tools for comparative genome analyses. In particular, they are interested in the early evolution of microbial life, and in the role that lateral exchange of genetic information played in forming the major groups of extant organisms. One previous study analyzed the origin and evolution of photosynthetic bacteria, and found that the genes that encode the photosynthetic machinery were transferred between divergent organisms. Apparently gene transfer is not limited of the spread of antibiotic resistance and to selfish genetic elements; it also affects housekeeping genes and characteristics that define major groups of prokaryotes. In a recent analysis Gogarten’s group studied the impact of even low rates of gene transfer on our ability to reconstruct ancestral genomes. Many features of the tree of life (or rather net of life) agree with a simple model based on coalescence theory. Simulations of genes and organismal lineages suggest that there was no single common ancestor that contained all the genes ancestral to the ones shared between the three domains of life. Rather each contemporary molecule has its own history and traces back to an individual molecular cenancestor, but these molecular ancestors were likely to be present in different organisms and at different times. Deviations of the real data from the simple model used as null hypothesis point towards changes in evolutionary mode and tempo that occurred in evolution.