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A recent study has revealed that life on Earth bloomed around 300 million years earlier than previously thought.
The research, published on October 19 in the journal Proceedings of the National Academy of Sciences, was led by a team of experts at University of California, Los Angeles. The scientists analyzed over 10,000 samples of zircon mineral, collected from the Jack Hills, in Mid West Western Australia.
656 fragments with unusual dark spots were initially selected, and 79 of them were further investigated using Raman spectroscopy and uranium-lead dating, by post-doctoral student Elizabeth Bell and her colleagues.
It was determined that these rocks, which were formed when volcanic magma crystallized, originate from a time when the Earth was just 400 million years old.
Moreover, within one of those tiny pieces researchers discovered graphite in 2 separate areas. This is actually a “chemo-fossil”, which has been described as “the gooey remains of biotic life”.
The carbon isotope mixture contains a higher proportion of Carbon-12, which is usually encountered when life decays. In some exceptional cases, such carbon signatures aren’t related to living organisms capable of photosynthesis, but that probability is extremely low.
While experts admit this isn’t “smoking gun evidence”, they still insist that the most plausible explanation for these carbon isotopes refers to the presence of tiny organisms.
These earth-shattering findings move the beginnings of life on our planet 300 million years earlier that it had been established, around 4.1 billion years ago.
At the time, according to former theories, Earth was in its Hadean geologic eon, marked by intense volcanic activity, after having been formed around 4.54 billion years ago.
Conditions had been considered as hellish and inhospitable, due to regular collisions with other Solar System bodies, and molten lava covering most of the surface.
Thus, it had been believed that it would’ve been impossible for the planet to support life during those ages, since there wasn’t even sufficient liquid water for organisms to develop.
Now it appears that this hypothesis might have to suffer some revisions. Researchers believe that in fact around 4.1 or 4.2 billion years ago the Blue Planet already had the building blocks of life, and behaved similarly to the way it does now.
Although around 3.9 billion years ago an incredibly large number of asteroids collided with early terrestrial planets, it seems that even if life disappeared during this heavy bombardment, it re-emerged shortly afterwards.
“Twenty years ago, this would have been heretical (…) Life on Earth may have started almost instantaneously. With the right ingredients, life seems to form very quickly”, explained Mark Harrison, geochemistry professor at UCLA and study co-author.
Stephen Blair Hedges, professor of evolutionary biology at Temple University’s Center for Biodiversity, has declared that these study findings are actually in correspondence with his own suppositions.
Moreover, according to him, the fact that life on Earth began at such an accelerated pace may suggest that it is also widespread in the universe as well.
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