Monday, January 30, 2017

Tree of Life


Our own trunk, known as eukaryotes, includes animals, plants, fungi and protozoans. A second trunk included many familiar bacteria like Escherichia coli.

The third trunk that Woese and his colleagues identified included little-known microbes that live in extreme places like hot springs and oxygen-free wetlands. Woese and his colleagues called this third trunk Archaea.

In greater detail, this means ...

The tree of life is one of the most important organizing principles in biology1. Gene surveys suggest the existence of an enormous number of branches2, but even an approximation of the full scale of the tree has remained elusive. Recent depictions of the tree of life have focused either on the nature of deep evolutionary relationships3,​4,​5 or on the known, well-classified diversity of life with an emphasis on eukaryotes6. These approaches overlook the dramatic change in our understanding of life's diversity resulting from genomic sampling of previously unexamined environments. New methods to generate genome sequences illuminate the identity of organisms and their metabolic capacities, placing them in community and ecosystem contexts7,8. Here, we use new genomic data from over 1,000 uncultivated and little known organisms, together with published sequences, to infer a dramatically expanded version of the tree of life, with Bacteria, Archaea and Eukarya included. The depiction is both a global overview and a snapshot of the diversity within each major lineage. The results reveal the dominance of bacterial diversification and underline the importance of organisms lacking isolated representatives, with substantial evolution concentrated in a major radiation of such organisms. This tree highlights major lineages currently underrepresented in biogeochemical models and identifies radiations that are probably important for future evolutionary analyses.

As a good friend of mine, versed in medical, once said, it's all computational now as we have the compute power to crunch the genome. Truer words were never said.

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