SCIENCE

Life Started On Earth 300 Million Years Earlier Than We Thought

"Life on Earth may have started almost instantaneously. With the right ingredients, life seems to form very quickly."

A group of scientists has found evidence that life on Earth may be much older than we thought. But good luck baking a birthday cake big enough for a proper celebration: It'd need to hold around 4.1 billion candles.

In a paper published online Tuesday, a team of geologists at UCLA revealed they've discovered a sample of carbon that could be the earliest trace of life ever found. While the prevailing theory holds that life began about 3.8 billion years ago, the potentially "biogenic" carbon (so-called because the carbon they found is a particular isotope commonly associated with living things) is 4.1 billion years old.

Researchers explained that the team sorted through more than 10,000 zircons from Western Australia in search of crystals that might contain dark specks, which could be carbon. Out of a potential 656 zircons with dark spots, 79 were analyzed, and only one actually contained carbon. 

Before they can conclusively say whether or not the carbon is from Earth's earliest known living thing, the team needs more data. Lots of it. Ideally 1,000 more zircons with carbon in them. "We figure such a dataset could be obtained for $15 million," Mark Harrison, a co-author of the study and a professor of geochemistry at UCLA, told The Huffington Post in an email, "or about 3% of the cost of a typical NASA planetary mission."

 

Carbon found in a piece of zircon indicates life on Earth began 300 million years earlier than previously thought.
Carbon found in a piece of zircon indicates life on Earth began 300 million years earlier than previously thought.

If confirmed, the carbon, found inside of an ancient zircon crystal, would push back the date for life on Earth about 300 million years.

That's significant, Harrison said, because "it further supports the picture ... that the planet was much more like today (i.e., oceans, continents, plate tectonics) than our longstanding paradigm of a desiccated, lifeless, largely molten Earth prior to 4 billion years ago."

"Twenty years ago, this would have been heretical; finding evidence of life 3.8 billion years ago was shocking," Harrison added in a press release. "Life on Earth may have started almost instantaneously. With the right ingredients, life seems to form very quickly."

Mark Harrison, pictured, and other geologists discovered carbon that indicates life on Earth began 300 million years earlier
Mark Harrison, pictured, and other geologists discovered carbon that indicates life on Earth began 300 million years earlier than previously thought.

 "The first time that the graphite [pure carbon] ever got exposed in the last 4.1 billion years is when [researchers] Beth Ann and Patrick made the measurements this year,” Harrison said. He added they're "very confident” in the finding.

Harrison told HuffPost the organism was likely a photosynthetic bacteria, noting that its composition of carbon isotopes "is exactly the same" as that of the average isotopic composition of organic matter found in the geologic record over the last 3.5 billion years.

"Our view of the first many hundreds of million years of Earth history as as a roiling, lifeless, and continent-free world was actually based on zero observational evidence,"
Harrison added, comparing it to "an origin myth similar in some ways to biblical creation."

Also on HuffPost:

PHOTO GALLERY
The Earth From Above
CONVERSATIONS