On a birthday cake in honor of the birthday of life it’s time to add a few more candles. 150 million candles, to be exact. Because the rock found in Northern Canada, has signs pointing to the fact that life appeared about a 3.95 billion years ago. This means that biological processes on our planet began much earlier than we previously thought.
This discovery was made by researchers at the University of Tokyo who conducted the analysis of the composition of carbon isotopes contained in sedimentary rock, taken in the North-Eastern part of the canadian province of Newfoundland and Labrador. Rocks investigated belong to the so-called Aoarashi era, the period of time of about 4 and 3.6 billion years ago when earth’s crust was still very young, and the atmosphere of the planet is very heavy and had virtually no oxygen.
As you might guess, rocks of this age on the road is unlikely to occur and difficult to detect. Of course, for all this the last time this breed was either melted beyond recognition or buried deep underground, or even just turned to dust. But those instances, which miraculously survived to our days, are a great source for finding signs of ancient chemical processes. One such rare instances, for example, is a stone found in Greenland in the isua Formation. Samples of this breed were the most ancient evidence of the existence of life is at least 3.7 billion years ago. However, the problem lies in the fact that such traces were not found in other similar stones Aoarashi era.
Unlike those of dinosaurs, from which we have at least left teeth and bones, more ancient life, as you can imagine, had a much more modest set of features to leave behind at least some mention of its existence. If we were talking about fossils, or any outlines of ancient bacteria study would have been much easier. However, we are talking about prints of early biochemistry, which are displayed in the form of graphite and carbonate.
After heating of the detected material and the subsequent analysis of the contained carbon isotopes, scientists can determine whether the biogenic samples (presented in the form of fossilized remnants of early cells) or are the result of a geochemical process.
Earlier detection of biogenic graphite in some samples of ancient rocks and its complete absence in others has slowed the true definition of the age of life. Fortunately, work has moved forward, when the researchers found the presence of this graphite in 54 canadian samples. And all the evidence suggests that this graphite is a product of vital activity of living systems. Moreover, the researchers found that the samples age at 150 million years longer than in samples from the isua Formation, which suggests that life was engaged in the formation of carbon atoms already through half a billion years after the formation of the planet itself.
During the heating process, scientists very carefully comply with the thermal balance, which allowed us to exclude contamination of samples. Given that “remains” are nothing more than a chemical signature of graphite and carbonate, in General they are little you can tell about the nature of the organisms that left them. However, they add certain details to the overall picture of how was the development of life, especially given that the conditions on early Earth were, this is clearly not the most suitable. As the researchers note, a similar analysis could effectively be used to search for signs of the living systems on other planets of the Solar system and beyond. Because in the end, the question of how life could appear on our planet or wherever it was, and still remains without a clear answer.
According to one theory, she could appear in the form of RNA, whose filament was formed and recombinable until then, until the nucleic acids can interact with other chemical processes. According to another theory, first appeared metabolic processes, and then appeared the replicate nucleic acid.
Earlier this year, Australian scientists found signs of life in ancient deposits near hot springs, whose age is estimated at 3.48 billion years, which begs the question of, if she could appear in a less oceanic environment.
There is even speculation that the present biosphere will disappear completely after a series of global extinctions and rapid restarts.
Despite many remaining questions, now researchers are beginning to draw conclusions about what chemical processes, through which came the living organisms on our planet, formed from the very appearance of the Earth.
New discovery scientists make life on Earth much older than
Nikolai Khizhnyak