Discovering evidence of Earth's oldest life

Stones that have just been found by Japanese scientists in northern Canada can reveal evidence of the first life on Earth.

The stones called Saglek Block in the northern part of Labrador, Canada have long been submerged under sea level, sucked into the Earth's heart, bent, suppressed and broken down by the internal forces that have emerged. on over time.

Although affected by weather such as wind, waves and abrasion for a long time, these rocks could exist about 3.95 billion years ago.

The oldest life

Researcher Tsuyoshi Komiya and colleagues at Tokyo University carefully analyzed these pieces of stone and found out something special: they contain most of the 12 carbon isotopes.

Isotopes are often distinguished by mass. Carbon 12, consisting of six protons and six neutrons in atoms, is lighter than carbon 13 - which contains more neutrons.

Although both forms exist in nature, living organisms prefer lighter isotopes because they are easier to incorporate into molecules. For this reason, when scientists found a large amount of carbon 12-rich graphite, they predicted the cause could be a long-lived organism.

Graphite found in fossils of 3.95 billion years may be the proof of the oldest life on Earth - (Photo: Tsuyoshi Komiya).

If the analysis is correct, these rocks contain the oldest signs of life found on Earth.

This finding also suggests that the origin of life may be much earlier, at times when the temperature is almost cold and the Earth often collides with other objects in the solar system.

In addition, this study could pave the way for the search for life on Mars, because scientists believe Mars is similar to Earth, so if life grows in this place, it will probably developed there.

"We can use the information recorded on Earth to outline where and what kind of environment is likely to find signs of life," said Abigail Allwood, NASA's cosmologist. said.

The study is published in Nature.

Not all studies are convincing

Previously, a study has shown that a stone of 3.77 billion years and a piece of bacteria 3.7 billion years ago could be "the first evidence of life on Earth." But this research has been controversial.

Furthermore, in general, the debate over this issue took place many decades ago and scientists have not been able to agree on what kind of evidence and how much is needed to prove that they are is a valuable fossil rather than merely a stone.

Someday, scientists will undoubtedly have similar structural debates in the rocks of other planets.

Earth is still changing. Although our planet has been around for 4.5 billion years, most of the rock is still "young", thanks to tectonic activities that help suck old stones into the mantle and melt them. .

Some other places on Earth where scientists can find the rocks that appeared at the beginning of the Earth such as Greenland, western Austria, and northern Canada.