New Evidence Shows Life on Earth Long Before We Knew

La Jolla
La Jolla

UCLA researchers believe they've discovered evidence that there was life on Earth hundreds of millions of years before previous benchmarks.

The stunning announcement this week means that life could have developed 4.1 billion years ago, beating previous estimates by as many as 300 million years, according to research by UCLA geochemists published in the journal Proceedings of the National Academy of Sciences.

"Twenty years ago, this would have been heretical," said Mark Harrison, co-author of the research and a professor of geochemistry. "Finding evidence of life 3.8 billion years ago was shocking."

What does this mean for humanity?

UCLA said in a statement this demonstrates that "life may have begun shortly after the planet formed 4.54 billion years ago."

Instead of previous theories that the planet was in its earliest days a boiling cauldron of magma, the discovery suggests that Earth looked more like it does today than we knew.

"For, five, 600 million years of Earth's history, it wasn't this boiling magma ocean dominated by extraterrestrial impacts," Harrison told us.

The formation of Earth as we know it happened much quicker than we thought, he suggests. And life, then, probably developed fast, too.

"Could life have emerged early?" he said. "In general it looks like this new picture emerging is more conducive to that."

So what?

Well, apply that to space, and this will start to blow your mind.

If life on Earth developed fast, with just rudimentary ingredients such as carbon, hydrogen, phosphate and sulfate, Harrison says, then the chances that extraterrestrial life exists are much higher following this discovery.

"If it emerged this quickly here ... it would be difficult to conceive that we are alone," Harrison said.

UCLA researchers studied more than 10,000 zircons formed from molten rocks found in Western Australia. Using Raman spectroscopy, they found a few traces of graphite — pure carbon — which is a key clue to the existence of life.

"They're [the zircon samples] screaming at us there was water, lots of it, probably continents, and possibly plate tectonics operating," Harrison told us. "The simplest explanation for that is the planet looked a lot more like it does today than this classic, hellish early Earth."

The graphite suggests not only life but fairly sophisticated life, at least 4.1 billion years ago.

"The result was a dead ringer for photosynthetic life, bacteria using external energy to make themselves food with fairly sophisticated metabolism," Harrison said.

"It's not smoking-gun evidence," he said, "but it's really suggestive."


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