The Two-domain Tree of Life is linked to a New Root for the Archaea


Readers will find this phylogeny paper on archaea interesting. The implications are further discussed by Baross and Martin in the second paper posted below. (h/t: Erich Schwarz)

An archaeal origin for eukaryotes is an exciting recent finding. Nevertheless, it has been based largely on the reconstruction of universal trees. The use of an alternative strategy based on markers shared between Archaea and eukaryotes and Archaea and Bacteria bypasses potential problems linked to the analysis of the three domains simultaneously. Comparison of the phylogenies obtained by these two complementary sets of markers supports a sister relationship between eukaryotes and the Thaumarchaeota/Aigarchaeota (candidate phylum)/Crenarchaeota/Korarchaeota lineage but also robustly indicates a root of the tree of Archaea that challenges the traditional topology of this domain. This sensibly changes our perspective of the ancient evolution of the Archaea, early life, and Earth.

John Baross and Bill Martin reviewed the implications of the above discovery -

The Ribofilm as a Concept for Life’s Origins

Recent phylogenetic data indicating that the first archaea were methane- producing galvanizes cross-disciplinary evidence supporting the hypothesis that life arose via thermodynamically directed events at hydrothermal vents. The new developments lead us to propose the concept of a ribofilm in which RNA’s origin-of-life role is more akin to a slowly changing platform than a spontaneous self-replicator.


Written by M. //

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