Top News

Life on Earth existed more than 3.7 billion years ago and has diversified!

At the beginning of the 20th century, there was reason to believe that planets and, in fact, planetary systems must be a rarity in the observable universe. We now know that around the stars the main sequences are almost inevitable. And what about the appearance of life on Earth? a huge coincidence with a very slow evolution or, conversely, an equally inevitable and very fast process, not only perhaps at the beginning of the archean 4 billion years ago, but only a few hundred million years ago after the birth of our Blue Planet during the serpents?

In 2017, a team that already included Dominic Papineau, who currently works at the Center for Planetary Sciences at London’s UCL Nanotechnology Center, made a grand announcement. Futura talked about this in an article below, and was based on a publication in the famous journal Nature.

Geoscience researchers have studied rocks from the Nuvvuagittuq Supracrustal Belt (NSB) located in Quebec. The stones were collected in 2008 by Dominic Papineau. NSB is also referred to as the Nuvvuagittuq Greenstone Belt. This rock formation, composed of metamorphic mafic and ultramafic volcanic rocks associated with sedimentary rocks, located on the east coast of Hudson Bay, 40 km southeast of Inukjuak, Quebec, is one of the oldest known on Earth.

Presentation of the discovery of possible microfossils at least 3.75 billion years old. To get a fairly accurate French translation, click on the white rectangle at the bottom right. Then English subtitles should appear. Then click on the matrix to the right of the rectangle, then on “Subtitles” and finally on “Automatically translate”. Select “French”. © UCLTV

It is estimated that there are rocks that could be between 3.75 and 4.28 billion years old. However, according to Dominic Papineau and colleagues in 2017, some of these rocks also contain structures and chemical compounds that seriously suggest that they are microfossils. If so, life on Earth already existed at least 3.75 billion years ago and would even have appeared 4 billion years ago, evolving rapidly to provide the various microfossils that appear to be observed in the NSB rocks.

This is contrary to the current paradigm, which believes that life could not appear until the beginning of the Archean, and that at that time he did not have much time to develop to take such different forms.

Biogenic or abiogenic structures?

Potential microfossils have, of course, been found in rocks similar to those on the NSB for decades, suggesting an environment similar to the hydrothermal vents in today’s oceans, an environment where life is believed to exist. It appeared using chemosynthesis, long before and after the discovery of photosynthesis. use of oxygen.

Serious doubts have always been raised about the biological origin of these microfossils or related chemical traces (see Hervé Martin’s explanation below), and even those from the NSB in Quebec have not avoided this rule. Today, however, Dominic Papineau and his colleagues return to the subject with new arguments to try to persuade skeptics, as we can read in a publication in Science Advances.

Have you ever seen dinosaur fossils? It’s hard to doubt their existence or imagine they could be produced abiotically! But what kinds of traces did the bacteria present on Earth more than 3.5 billion years ago leave? How to find the oldest traces of life on Earth? With Hervé Martin, unfortunately already deceased geologist, explanation in 10 min. © French Society of Exobiology

It was an attempt to show that the fibrous structures already observed – reminiscent of populations of microorganisms already diversified due to surprisingly rapid evolution more than 3.75 billion years ago – were not abiogenic products, such as infiltration deposits of iron-rich waters. heated by magma in ancient rocks, but subsequently after their formation.

The observed structures are actually made of hematite, which is a form of iron oxide or rust, and enclosed in quartz. Their study was renewed by cutting new sections about paper (100 microns) thick in rocks collected in 2008. At the time, it was easier to make a comparison with what could be observed with oxidizing iron bacteria, which are now found near hydrothermal ventilation systems.

As explained in the UCL press release accompanying the article by Dominic Papineau and colleagues, these researchers were then clearly able to demonstrate that we were in the presence of forms truly equivalent to twisted fibers, with parallel branched structures and deformed spheres. found in rocks of current hydrothermal vents, such as near the Loihi submarine near Hawaii.

Observation techniques using mainly X-rays and expert image processing using powerful computers have made it possible to confirm that the hematite fibers were wavy and twisted and contained organic carbon, which are properties shared with carbon-consuming microbes. modern iron, as has always been explained in the UCL press release.

From all these data, the scientists deduced that, according to them, hematite structures could not have formed by compressing and heating the rocks much later, with a metamorphosis that would work over billions of years. serpentine.

Author Hervé Cottin, Astrochemist, University Professor, Lisa, University of Paris Est Créteil / University of Paris / CNRS Discover the web Are we alone in space? You may have already asked yourself a question … We can find the answers in movies, literature or sci-fi comics and our imagination is populated by alien creatures! But what does science say? AstrobioEducation invites you to discover exobiology, an interdisciplinary science that aims to study the origins of life and its research elsewhere in the universe. Through an educational journey divided into 12 stages, researchers from various disciplines will help you understand how science works to answer the fascinating questions of the origin of life and its research outside of Earth. © French Society of Exobiology

Origin of life: the oldest fossils that may have been found in Quebec

Article by Laurent Sacca published on March 2, 2017

For decades, geologists have discovered interesting structures that suggest that they are microfossils more than 3.5 billion years old. Nevertheless, these findings are often questioned. The latest would break all records: presumed microfossils were found in Quebec in rocks at least 3.77 billion years old.

The geological records of the Earth are becoming increasingly scarce and increasingly difficult to decipher as one returns in time from the archean to the hadean. It is therefore particularly difficult to determine when life occurs on Earth.

In 2008, however, scientists made a surprising announcement. According to them, the rocks present along the shores of Hudson Bay in northern Quebec – in the area called “Nuvvuagittuq Greenstone Belt” (Nuvvuagittuq Supracrustal Belt, in English or NSB) – were in place about 4.3 billion years ago, only a few hundred million years after the creation of the Earth.

Now an international team of geoscience researchers has just published an article in Nature announcing the discovery of traces of life forms in rocks in the same area of ​​Quebec that would be at least 3.77 billion years old, and possibly more: up 4.3 billion years old. If so, it would be the oldest known evidence of the existence of living organisms on Earth.

Hydrothermal springs at the birth of life?

In this case, the researchers believe that they have discovered microfossils, ie fossilized remains of microorganisms. Previously, similar remains found in Western Australia with an estimated age of 3.46 billion years were held (see also the article below on the possible finding of fossilized remnants of stromatolites built by cyanobacteria 3.7 billion years ago). The putative Nuvvuagittuq microfossils are in the form of tubes and fibers of hematite (iron oxide mineral), which are located inside the quartz layers.

If this discovery were to be confirmed, it would be interesting in several respects:

  • You should already know that the Nuvvuagittuq Greenstone belt contains sedimentary sediments and other rocks that indicate …