Authors: James T Staley
Publish Date: 2009/09/25
Volume: 36, Issue: 11, Pages: 1331-1336
Abstract
The Universal Tree of Life which is based on phylogenetic analysis of the RNA sequence from the small ribosomal subunit was a breakthrough in understanding the relatedness among all living organisms The result has had a major impact on taxonomy by separating life into three domains Eukarya Bacteria and Archaea Indeed microbiologists have used the 16S ribosomal RNA rRNA of the small ribosomal subunit to construct the hierarchical classification of Bacteria and Archaea from the level of domain to genus However the 16S rRNA of the Bacteria and Archaea and the corresponding 18S rRNA of the Eukarya are too highly conserved to be useful phylogenetically at the species level For this reason I propose that biologists adopt a phylogenomic species concept that utilizes both phylogenetic analyses of less highly conserved genes and proteins as well as genomic analyses for the circumscription of species If biologists adopt a phylogenomic concept for species the classification of all living organisms from domain to species could be completed Furthermore this universal species concept could help provide a more equitable circumscription among all species as well as aid in the unification of biologists and biology
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