“We need to think differently about the early Earth.”
A team of geochemists at the University of California at Los Angeles (UCLA) have just found evidence that there was life on Earth 4,100 million years ago, ie, 300 million years earlier than previously thought. The finding implies that life came into existence very soon after our world was formed, 4.554 million years ago. The work was recently published in Proceedings of the National Academy of Sciences (PNAS).
“Twenty years ago, this would have been heretical; finding evidence of life 3.8 billion years ago was shocking,” said Mark Harrison, co-author of the research and a professor of geochemistry at UCLA.
“Life on Earth may have started almost instantaneously,” added Harrison, a member of the National Academy of Sciences. “With the right ingredients, life seems to form very quickly.”
According to this new study, life existed on our planet even before the massive bombardment of the inner solar system some 3,900 million years ago when numerous celestial objects crashed into the Moon and Earth.
“If all life on Earth died during this bombardment, which some scientists have argued, then life must have restarted quickly,” said Patrick Boehnke, a co-author of the research and a graduate student in Harrison’s laboratory.
Countless researchers believed that the Earth was a desolate and parched planet in the distant past, but just as we learned from what we have found out on Mars, it isn’t quite as science suggested.
“The early Earth certainly wasn’t a hellish, dry, boiling planet; we see absolutely no evidence for that,” Harrison said. “The planet was probably much more like it is today than previously thought.”
Under the supervision of Elizabeth Bell, a researcher from UCLA, experts studied over 10,000 zircons formed from molten rocks from Western Australia. Zircons capture and preserve their immediate environment which has led researchers to nickname them ‘time capsules’.
According to a report from UCLA’s website, scientists identified 656 zircons containing dark specks that could be revealing and closely analyzed 79 of them with Raman spectroscopy, a technique that shows the molecular and chemical structure of ancient microorganisms in three dimensions.
Researchers had one goal, look for carbon, a key component for life. Interestingly, one of the 79 zicrons contained graphite in two locations.
Researchers are very confident that these ziccros actually represent 4.1 billion-year-old graphite. “There is no better case of a primary inclusion in a mineral ever documented, and nobody has offered a plausible alternative explanation for graphite of non-biological origin into a zircon.”
Harrison added that the research suggest that life as we know it in the universe could be abundant since on our planet, simple life appears to have formed very fast.
Source and reference: UCLA