Search results for "Last universal ancestor"

Molecular Phylogeny of Eumetazoa: Genes in Sponges (Porifera) Give Evidence for Monophyly of Animals

1998

At present, the universal phylogenetic tree exhibits a tripartite division of the living world and includes Bacteria (“eubacterial”), Archaea (“archebacterial”), and Eucarya (“eukaryotic”) branches (Woese et al. 1991) with the Progenote as the common ancestor (Woese 1987). It is difficult to assess the timely appearance of the first living organism. Some first decipherable evidence of early life has apparently been identified in Swaziland (South Africa) and Pilbara Supergroup (Western Australia) sediments, and dates back 3550 to 3000 Ma (million years) ago; these are stromatolites (see Walter 1996), microfossils, and particulate organic matter (reviewed in Schopf 1994). Eucarya are roughly …