title: Physiology, phylogeny, and LUCA.
abstract: Genomes record their own history. But if we want to look all the way back to life's beginnings some 4 billion years ago, the record of microbial evolution that is preserved in prokaryotic genomes is not easy to read. Microbiology has a lot in common with geology in that regard. Geologists know that plate tectonics and erosion have erased much of the geological record, with ancient rocks being truly rare. The same is true of microbes. Lateral gene transfer (LGT) and sequence divergence have erased much of the evolutionary record that was once written in genomes, and it is not obvious which genes among sequenced genomes are genuinely ancient. Which genes trace to the last universal ancestor, LUCA? The classical approach has been to look for genes that are universally distributed. Another approach is to make all trees for all genes, and sift out the trees where signals have been overwritten by LGT. What is left ought to be ancient. If we do that, what do we find?
authors.affiliation: Institute for Molecular Evolution, Heinrich-Heine Universität Düsseldorf, Universitätstrasse 1, 40225 Düsseldorf, Germany. ; Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal.
authors.forename: William F
authors.initials: WF
authors.lastname: Martin
authors.affiliation: Institute for Molecular Evolution, Heinrich-Heine Universität Düsseldorf, Universitätstrasse 1, 40225 Düsseldorf, Germany.
authors.forename: Madeline C
authors.initials: MC
authors.lastname: Weiss
authors.affiliation: Department of Ecogenomics and Systems Biology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria.
authors.forename: Sinje
authors.initials: S
authors.lastname: Neukirchen
authors.affiliation: Computational Biology & Bioinformatics Group, Rajiv Gandhi Centre for Biotechnology (RGCB), Trivandrum, Kerala 695014, India.
authors.forename: Shijulal
authors.initials: S
authors.lastname: Nelson-Sathi
authors.affiliation: Department of Ecogenomics and Systems Biology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria.
authors.forename: Filipa L
authors.initials: FL
authors.lastname: Sousa
keywords: acetogens; autotrophy; early evolution; geochemistry; methanogens