Note in Science page
Created Jul 26 16, Updated Jul 26 16 18:08
Last Universal Common Ancestor probably evolved in hydrothermal vents go to comments

We investigated all clusters and phylogenetic trees for 6.1 million protein coding genes from sequenced prokaryotic genomes in order to reconstruct the microbial ecology of LUCA. Among 286,514 protein clusters, we identified 355 protein families (?0.1%) that trace to LUCA by phylogenetic criteria.

Their functions, properties and prosthetic groups depict LUCA as anaerobic, CO2-fixing, H2-dependent with a Wood-Ljungdahl pathway (1), N2-fixing and thermophilic.

The 355 phylogenies identify clostridia and methanogens, whose modern lifestyles
resemble that of LUCA, as basal among their respective domains. LUCA inhabited a geochemically active environment rich in H2, CO2 and iron. The data support the theory of an autotrophic origin of life involving the Wood-Ljungdahl pathway (1) in a hydrothermal setting.


Hydrothermal vent (wikipedia)

Hydrothermal vent on wikipedia

Reference:
The physiology and habitat of the last universal common ancestor,
Nature Microbiology (2016). DOI: 10.1038/nmicrobiol.2016.116

phys.org article

note (1): Wood-Ljungdahl: This pathway enables certain organisms to use hydrogen as an electron donor and carbon dioxide as an electron acceptor as well as a building block for biosynthesis.


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