Although it is not known when or where life on Earth began, some of the earliest habitable environments may have been submarine-hydrothermal vents. Here we describe putative fossilized microorganisms that are at least 3,770 million and possibly 4,280 million years old in ferruginous sedimentary roc...
As the latter value is broadly characteristic of oxygenating photosynthesis, this relationship has been seen as evidence of past biologic activity. However, as metamorphic grade increases, kerogens are reacted to simpler hydrocarbons, ultimately yielding graphitic residues. The discovery of isotopically ...
J. et al. Evidence for life on Earth 3800 million years ago. Nature 384, 55–59 (1996). ADS CAS PubMed Google Scholar Rosing, M. T. 13C-depleted carbon in >3700 Ma seafloor sedimentary rocks from West Greenland. Science 283, 674–676 (1999). ADS CAS PubMed Google Scholar ...
This could explain why the evidence of the earliest life on Earth appears during the Hadean — maybe the planet was less inhospitable during that eon than previously thought. This artist's illustration shows a close-up of the early Earth, revealing magma extrusion on the surface and the scars...
According to the Oparin Haldane hypothesis, life on Earth could have arisen from step to step over millions of years from non-living matter through a process of gradual chemical evolution. Many events could have led to the origin of life on Earth under an oxygen-deficient atmosphere,...
Earth would not have supported very much life. A methane-rich atmosphere formed in connection to large-scale iron ore deposits and life was initially proposed by University of Michigan atmospheric scientist James Walker in 1987. The new study provides strong physical evidence to supp...
"This is an exciting discovery -- for the first time, we're able to show the world that these stromatolites are definitive evidence for the earliest life on Earth," lead researcher Dr Raphael Baumgartner from UNSW said. Ever since their discovery in 1980 it has been hotly contested whether...
31. Life originated in the early seas less than a billion years after the Earth was formed. Yet another three billion years were to pass before the first plants and animals appeared on the continents. Life's transition from the se a to the land was perhaps as much of an evolutionary chal...
5e. Search for the Earliest Evidence of Terrestrial life (Elizabeth Bell, University of California, Los Angeles). The search for the earliest evidence of life must include three perspectives: whether a structure is biological (textural, chemical, and isotopic), how well the age of the host rock...
This has important implications for exploration of signs of life beyond our solar system, because searching for traces of atmospheric oxygen is one way to look for evidence of past or present life on another planet – or what scientists call a biosignature. Ironstones within the sedimentary ...