A research group led by Associate Professor Tsuyoshi Komiya of the Graduate School of Arts and Sciences, the University of Tokyo, has succeeded in finding traces of life activity by investigating 39.5 billion-year-old sedimentary rocks from the Saglek body of Labrador, Canada.With this achievement, the traces of the oldest life in the world go back more than 1.5 million years from previous estimates.
The elucidation of when and where life was born on the earth is still halfway.The earliest known traces of life have been found in sedimentary rocks in the Isua region of southern West Greenland, and are said to be 37-38 billion years old.
This time, the research group investigated marine sedimentary rocks 39.5 billion years ago and discovered that fine graphite (carbonaceous fine particles) exists in multiple sedimentary rocks.By analyzing these in detail, it was clarified that the graphite discovered was deposited on the seafloor at that time, and that it was generated through the metabolic fractionation pathway by life such as the reducing acetyl-CoA pathway and the Calvin cycle. I made it.
This achievement provides the world's first evidence of geoscientific evidence of life activity in the ocean about 40 billion years ago.It is expected that further analysis and evaluation of the microbial species that inhabited the ocean at that time will lead to their identification.The method used in this study can be applied to other Archean samples and meteorites of Martian origin, and can be said to be an extremely important achievement that contributes to the elucidation of the evolutionary history and origin of life in early life.
Paper information:[Nature] Early trace of life from 3.95 Ga sedimentary rocks in Labrador, Canada
