Academic Thesis

Basic information

Name Satou Tomohiko
Belonging department
Occupation name
researchmap researcher code B000334895
researchmap agency Okayama University of Science

Title

History of the Hadean "Living Microfossil" OD1 and Ultra-reducing Environments

Bibliography Type

 

Author

Sato, Tomohiko
Yoshiya, Kazumi
Maruyama, Shigenori

Summary

Phylogenetic analysis is one of the useful tools available for revealing the evolution of life on the Earth; however, it has difficulty in principle distinguishing old and new genomes just by comparing phylogenomic trees. To overcome this difficulty, a new method is introduced which utilizes the Earth's history derived from geologic information to trace genomic evolution. This idea is inspired by Darwin's natural selection, and explains how living organisms change with the environment. In other words, life's genome does not change if the environment remains the same. A key is the birthplace of life on Hadean Earth, which is thought to be an ultra-reducing environment with H2 produced in abundance through serpentinization. OD1 is a potential microbe that has survived on the Earth since the Hadean. Its habitat, Hakuba-Happo in Japan, is a unique serpentinite-hosted hydrothermal system on land, and it has avoided evolution by remaining in a super-reducing environment from the Hadean to the present. OD1 is regarded as a "living fossil" of the Hadean microbe. Ultra-reducing environments have disappeared over the Earth's history. How has OD1 survived since the Hadean to the present? A possible scenario is proposed based on Plate Tectonics. OD1 habitats have gone through the following transitions: (1) super-reducing environment in a natural nuclear geyser on a primordial continent in the Hadean; ,2 serpentinite-hosted hydrothermal system along a mid-oceanic ridge transform fault during the Archean-Proterozoic; (3) subduction-accretion and escape from oxygenated Phanerozoic ocean floor; and, (4) jacked up by growth of accretionary complexes and taking refuge in a hydrothermal system above a volcanic front. OD1 habitats have been reduced with geological age as free oxygen has increased in the surface environment. OD1 may be a "living microfossil" of the Hadean, making its way continuously through ultra-reducing environments on a tightrope.

Magazine(name)

JOURNAL OF GEOGRAPHY-CHIGAKU ZASSHI

Publisher

TOKYO GEOGRAPHICAL SOC

Volume

128

Number Of Pages

4

StartingPage

571

EndingPage

596

Date of Issue

2019

Referee

Exist

Invited

Not exist

Language

Japanese

Thesis Type

Research papers (academic journals)

ISSN

 

DOI

10.5026/jgeography.128.571

NAID

 

PMID

 

J-GLOBAL ID

 

arXiv ID

 

ORCID Put Code

 

DBLP ID