Horizontal Gene Transfer and the Evolution of Life on Earth

University Of California-Los Angeles, Los Angeles CA

Investigators

Abstract

The principal investigators on this project propose to analyze the genomes of the diverse life forms found on Earth and to relate their interrelationships to the geological, paleontological, climatological, chronological, and biochemical records. They will take into account the effects of horizontal gene transfer using newly developed mathematical algorithms. Horizontal gene transfer refers to the passing of genes between different organisms, much like computer programmers share programs over the internet. This exchange has had an important influence on the evolution of prokaryotic (bacterial) life. But at the same time, it greatly complicates reconstructing the tree of life. They have three related objectives. Among the objectives of the investigators will be to correlate genomic information with theories for the origins of the bacterial life on Earth. Also, methods will be developed so that one can utilize complete genome information in order to derive phylogenetic trees which can accurately resolve major events in the history of life and yet not be affected by the complexities of horizontal gene transfer. These genome comparisons, will be related to the fossil and geological records, through correlation with such factors as the time of appearance of oxygen in the atmosphere, the isotopic abundances of sulfur and carbon, and the appearance of eukaryotic and prokaryotic fossils, in order to understand past changes on the Earth and predict future changes. The proposed basic research also has broader impacts on society. For example, by clearly understanding the evolution of prokaryotic and eukaryotic cells and of their biochemical pathways, these studies may suggest new technologies. In particular, understanding how organisms have evolved to live in extreme environments may lead to new and more efficient industrial processes. In another sphere, the correlation of genomic data with phylogenetic, geological, climatological, and paleontological data may provide clues to the evolution of life on Earth and life's response to past environmental crises. For example, understanding the evolution of life during "Snowball Earth", may provide critical information that could have practical applications to such important problems as global warming. Additional impacts will result from teaching and training graduate and undergraduate students, and from the dissemination of scientific information to the public, especially to underrepresented groups. This lab consists of 8 scientists, five are female and three are males. The Co-PI (one of two Latinas in the lab) has lectured frequently at public forums that serve minority groups. During the past summer the lab hosted the Professor in charge of Tennessee State University minority program to learn genomics. This lab is very concerned about the broader impacts of their research.