Oldest traces of life on Earth found in Quebec, dating back roughly 3.8 billion years

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A team of international scientists has found the oldest record of life on Earth in Northern Quebec, dating back at least 3.8 billion years.

Our solar system formed about 4.6 billion years ago. Scientists believe that about 4.3 billion years ago, water already existed on Earth’s surface. However, what isn’t known is when the earliest life emerged. Recent research has found life at 3.4 billion years and, most recently 3.7 billion years.

The discovery was made in the Nuvvuagittuq Greenstone Belt in Northern Quebec in rock known as “banded iron formations.” These formations existed billions of years ago, a result of organisms reacting with dissolved iron in the water that covered the planet. They appear in rock as red or white layers.

Johnathan O’Neil, assistant professor at the University of Ottawa’s Department of Earth and Environmental Sciences, holds a sample of rock taken from the area where he and the research team discovered microfossils of the oldest life forms ever found on Earth. (Dave Weatherall)

While there is some debate as to whether or not the the age of the rock in the Nuvvuagittuq Greenstone Belt is 3.8 billion years old or 4.3 billion years old, Jonathan O’Neill, assistant professor at the University of Ottawa’s Department of Earth and Environmental Sciences, believes it to be on the older side. But even if the rock is younger than that, it would still make their finding the oldest record of life on Earth, by 100 million years.

“It’s impressive,” O’Neill said. “We now have evidence in rock that I can hold in my hand that we had life already established extremely early on the Earth.”

Discoveries such as this one greatly help scientists better understand the early Earth. O’Neill said that scientists had previously theorized that Earth was a truly inhospitable place at this young geological age, a searing, active world with molten lava lakes incapable of supporting any surface water or life. However, O’Neill said that recent research is painting a far different picture.

“Within the last 15, 20 years, we have more and more evidence that that’s not the case,” he said. “Very quickly after its formation, the Earth became closer to what it is today. We already have evidence of water at the surface of the Earth by about 4.3 billion years ago.”

And it’s in that water, together with thermal activity below where life began to flourish, first as microorganisms.

Below the surface water, the ocean crust would have been literally bubbling with activity: with hydrothermal vents, the water heated by volcanic activity.

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