Scientists have found microfossils within rocks in Canada that could be proof of the earliest life on Earth, between 3.77 and 4.28 billion years ago.

A paper on the discovery was published in the journal Nature. Matthew Dodd from the University College London is the lead author of the paper.

The microbe fossils were found in sedimentary rock that was part of the Nuvvuagittuq Supracrustal Belt. Off the northeastern Canadian coast, this iron-rich rock used to be ancient oceanic floor, likely formed around a series of submarine-hydrothermal vents.

That brings about the presumption that deep sea vents may have played an important role in the formation of lifeforms, said Steve Dorus, associate professor of biology at Syracuse University’s College of Arts and Sciences.

The recently discovered microbe fossils contain a certain combination of chemicals that most likely could have been created only by a biological process, according to The Washington Post.

When the microbes that lived around the hydrothermal vents died, the iron in the water was deposited inside their bodies and their cellular structures turned to stone, per The Washington Post.

Other minerals present in the rock, such as magnetite, carbonate and apatite usually form around organic matter. Graphite found in the rock also contains an isotope, carbon-12, that is “considered an isotopic signature of life,” according to The Washington Post.

Other scientists have said these fossils look similar to fossils found in more modern rocks that are situated near hydrothermal vents.

The rock the fossils were found in has certain properties which make it ideal for preserving fossils, said Linda Ivany, a professor of earth sciences at SU, in an email. The rock is composed of quartz, which is resistant to weathering, and the rocks haven’t experienced a lot of tectonic alteration deformation since they were formed.

Dorus said one impact of this discovery could be researchers will have more knowledge on the conditions of fossil deposition.

“That may in turn provide some clues about how one would look for environments on other planets,” he said.

Ivany added that many ancient fossils have been hidden in glaciers, but with climate change causing the ice to melt, the oldest fossils are being revealed, giving scientists several more research opportunities. She said there are very few other places on earth that have preserved rocks this old.

Both experts agree that the fossils show the prerequisites for life may not be as complicated as researchers previously thought.

“It was kind of inevitable,” Ivany said. “If you have the right set of physical/chemical conditions that reactions will take place that will ultimately give rise to something that we can recognize as life.”

She added that if these conditions are met on other planets, then researchers can expect to find life on those planets, as well.

Previously, the earliest discovered fossils were only a couple hundred million years younger than those in this study, Dorus said. He added that because of this, there’s also going to be skepticism over how accurate the dating of the fossils is.

Dorus added that as scientists continue to find older fossils, at a certain point, there are going to be diminishing returns. This means there’s going to be a smaller and smaller window of time for scientists to find fossils that were older than ones discovered previously, he said.

“We’re going to run out of progress to be made,” he said.

Published on March 6, 2017 at 11:29 pm

Contact Sandhya: ssiyer@syr.edu