Fossils indicate life on Earth older than expected

The team of researchers say the rocks located at the Isua Greenstone Belt, were covered with ice and snow, which melted after an unusually warm spring. Until now, scientists wondered whether the lakes on Mars persisted long enough for life to spring up, but now, she says, “what we’re potentially seeing is evidence that life can get a foothold in such a short time frame”.

Stromatolites are layered structures that form in shallow water due to grains of sand and mud being bound together by microorganisms. But the identity of whatever was living 3.7 billion years ago is obscured by the altered state of rock from that era, which over the eons has been cooked and twisted beyond recognition.

Indeed, recent discoveries have offered tantalising suggestions that organisms could have been around 4.1bn years ago, while the authors note that so-called “genetic molecular clocks” also suggest that life is likely to have emerged around that time.

These stromatolites are the oldest fossils ever discovered.

September 1,2016- Fossils as defined in a dictionary are the remains or impression of a prehistoric plant or animal embedded in rock and preserved in petrified form.

Stromatolites are fairly complex structures that are still made by microbes alive today.

“It would have been a very different world”, he said.

The discovery pushes back the fossil record to near the start of Earth’s geological record and points to evidence of life on Earth very early in its history.

While the earliest known life on Earth is now believed to have come from Greenland, the researchers don’t think there is any particular significance to that location. The discovery shows that life arose on Earth relatively early in its history, and that it was able to survive the harsh conditions of the Hadean epoch. Other scientists, however, caution that it’s possible the wavy formations in the rocks could have occurred through natural, rather than biological processes, and a conclusive determination can be hard in rocks so old.

Newly unearthed microbial fossils suggests life thrived on Earth earlier than previously thought.

Writing in the journal Nature, they said: ‘The recognition of 3,700 million-years-old biogenic stromatolites within Isua dolomites indicates that near the start of the preserved sedimentary record, atmospheric Carbon dioxide was being sequestered by biological activity.

According to Professor Allen Nutman, a geologist at the University of Wollongong in Australia, and his team who discovered the new fossil, it may have been the latter.

“The stromatolites predate by 220 million years the previous most convincing and generally accepted evidence for oldest life remains in the 3,480 million-year-old Dresser Formation of the Pilbara Craton, Australia”, they added. Instead, they are metamorphic rocks, which means they have been repeatedly heated and cooled over the last few billion years. This in way raises the chances of life on Mars aeons ago when both planets were similarly desolate, scientists said on Wednesday. Paris Institute of Earth Physics researcher Pascal Philippot, who has worked on those oldest Australian stromatolites, told Ars that having only a few specimens to look at makes this tricky.

The finding could also have implications for our understanding of the possibilities of life on other planets, particularly on Mars, which featured standing bodies of surface water similar to Earth’s 3.7 billion years ago.

“If these are really the figurative tombstones of our earliest ancestors, the implications are staggering”, Dr. Allwood wrote. “The chemical evidence could be interpreted as signs of life, but there’s always been some element of doubt”, says Nutman. “To the extent that that is true, life ought to be abundant in the universe-because there are lots of Earth-like planets out there”. While the Greenland stromatolites were forming, Mars was still a wet planet.