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Discovered the first forms of life?
The microfossils found in a Canadian rock could be remains of organisms of 4.28 billion years ago. But not all scientists agree. Filaments of iron-rich minerals, each of which much thinner than a human hair, could be the remains of the very first forms of life appeared on our planet, shortly after his birth. According to scientists who discovered them, these tiny tubules of hematite may have up to 4.28 million years, and they are incredibly similar to structures produced by microbes that still live near hydrothermal vents.
Discovered in rock fragments collected in northern Quebec, microscopic metal debris – which carry with them “signatures” chemical associated with older forms of metabolism – would thus be proof that life appeared on Earth much earlier than previously thought: in fact, until now it was thought that the oldest traces of life were the stromatolites than 3.7 million years ago found in Greenland.
The microfossils also confirm the theory that the warm waters, deep and rich in minerals around underwater hydrothermal sources are ideal environments for the emergence of life on our planet is that, eventually, on the bottom of the frozen oceans of some satellites, or maybe other points in the universe. If you really are correct analyzes and interpretations of the team of scholars, then life emerged on Earth very soon, soon after the planet had begun to stabilize. As soon as the ‘geological foam’ began to cool, biology emerged as typical of our planet process. Despite being rich in iron, though, these fossils may not provide ironclad evidence about the presence of life forms so ancient. Some scientists doubt that it is the remains of microbes; others argue that the age of the crystals containing the supposed microfossils is controversial, and could be even later than a billion years. These rocks have a long and complicated story, will be increasingly difficult to establish with certainty the age and origin. In 2008, a London team has collected rocks from the formation of Nuvvuagittuq, on the east coast of Hudson Bay, where once a hydrothermal source spilling lava on the seafloor. They are among the oldest rock fragments of the planet, and preserve the marine environment traces of prehistoric Earth.
In fact, scholars no ernment hunting for microfossils, but something even more difficult to find: the organic traces of the first microorganisms. According to a hypothesis well-established, life could have originated in hydrothermal environments. Canadians deposits were certainly a promising place to search for signs of primitive life. The researchers cut off the rocks into very thin sections; looking at them under a microscope, they noticed the fossils, which were collected in crystals in turn embedded in the rocks. Although tiny, they were remarkably intricate and complex structures, so that the team became suspicious: maybe it was not just the organic traces. The situation reminded him of a discovery that is still discussing now. In 1996, examining a meteorite of Martian origin found in Antarctica, a team of scientists identified other tubular structures that looked like the remains of living organisms. Today, most scientists believe that they were not living origin, but the issue is still controversial.
Perhaps remembering that incident, the researchers looked for any sort of confirmation that the facilities they had found were remnants of a form of metabolism and not just pieces of rock washed by sea water. Studying the materials that surrounded the fossil, they found carbon-containing compounds that seemed to bear the imprint of a biological process. In addition, the fossils were surrounded by minerals containing phosphorus, an element found in “bricks” the basis of life, and released by the bodies during decomposition. There were two other possible traces of biological processes: granules of carbonaceous material and oxidized iron. Moreover, say the scholars, the tubules and the filaments were arranged in less random than it would happen if they were not of biological origin. Are all independent chemical sources of evidence from one another that, associated with the structure of microfossils, show that it is organic matter of biological origin. The researchers also compared the microfossils with other microbial structures found around hydrothermal springs 480 and 150 million years ago, respectively, in Norway and in the United States, and with micro-organisms currently living around the underground springs. In all cases, the similarities are striking: all evidence that the microfossils are residues of living beings.
But not everyone is convinced. The chemical evidence submitted to prove the biological origin – in particular the analysis of the carbon compounds – are weak and ambiguous. And that tubules and filaments may have been formed by hydrothermal fluid or by another process that has deformed the rock, although the authors of the research have rejected the idea. Even if it was with every safety of fossils yet to resolve the question of their age. Using two different types of measurement based on isotopes, the researchers concluded that the rocks should be between 3.77 and 4.28 billion years. But other scientists argue that in rocks so complex determine the age of each characteristic is difficult, and dating may not be as accurate. According to them the structures that contain the fossils (fossils are admitted) may also be a lot more recent: “only” 2.7 billion years. At that time, the entire formation of Nuvvuagittuq was drastically altered by cycles of high pressure and high temperature caused by tectonic activity, which might have stretched, bent and distorted the rocks, destroying any remaining fossil. It has already been tried in several cases that the fossils can even survive such devastating events. The idea that the metamorphic rocks can not preserve the fossil is dated. If the study were to prove correct, it would mean that already relatively complex organisms have evolved already before losing their “skin” ferrous and thrive already a few hundred million years after the violent birth of the planet: the blink of an eye, in terms geological, who sends in fibrillation scientists investigating the possible presence of life in the cosmos. In particular, the frozen oceans on Jupiter‘s moons and Saturn would prove the ideal places in which to search for living organisms.
Even more interesting is to consider that Canadians microfossils are completely different from stromatolites, photosynthetic microorganisms such as those older than 3.7 billion years discovered in Greenland. Their simultaneous presence suggests what has been dogged life, how has diversified to survive even as the Earth was in the throes of spasms earthquakes, volcanic eruptions and bombing from space rocks.
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