Author Irina Shlionskaya yesterday at 14:00
Traditional scientific theories claim that life on our planet arose only much later after the Earth itself formed. However, a group of geochemists from the University of California at Los Angeles (UCLA) believes that the first living organisms could appear even 4.1 billion years ago — shortly after the formation of the planet.
Zircons and the history of the Earth
For a long time it was believed that the young Earth was a barren desert, on which there was no room of life. And only about 3.8 billion years ago, conditions have become sufficiently favorable for the origin of living organisms.
However, recent studies suggest that life on our planet existed before the Solar system was subjected to the inner asteroid bombardment, which today resemble giant craters age, 3.9 billion years.
“If all life on Earth perished during this bombardment, as evidenced by some scientists, then the life that was to transform,” says one of the authors of a new study, graduate student Patrick bene.
Meanwhile, a team from UCLA found evidence that at least 4.1 billion years ago life on Earth was present. Geochemistry Professor mark Harrison and his colleague, Professor of Geology and Geochemistry of the Craig a manning co-authored with former UCLA graduate student Michelle Hopkins back in 2008, published in the journal Nature article, which proves my theory.
The researchers studied more than 10,000 samples of zircon, formed from molten volcanic rocks in Western Australia at the dawn of the planet formation. The ratio in these rocks of carbon-12 and carbon-13 indicates the presence of photosynthetic life.
Highlighting 656 specimens with dark spots, the researchers subjected the 79 Raman spectroscopy — methods, which you can use to see the molecular and chemical structure of ancient microorganisms in three-dimensional models. It turned out that one of the samples in two places that has inclusions of graphite are pure carbon. The ratio in a mineral of uranium to lead has helped to determine the age of 4.1 billion years. But graphite may be older than other components.
“This is the best-documented cases of direct inclusion in the mineral, and no one has still not offered a decent alternative explanation of this graphite non-biological origin of the zircons,” says Harrison.
How were the process of evolution
According to scientists, life on Earth can exist everywhere, and it requires not so much time that it arose. In all probability simple organisms appeared on Earth almost immediately after it was formed, but it took many millions of years, they have developed the ability to photosynthesize, so they were able to directly use solar energy.
This contributed to the filling of the atmospheric oxygen (which occurred approximately 2.5 billion years ago) and the formation of the ozone layer absorbing harmful ultraviolet radiation.
Further, the processes of the symbiosis of small cells with larger has led to the development of more complex living cells — eukaryotes. About 2.1 billion years ago multicellular organisms. The process of adaptation to the environment continued.
About 1200 million years ago appeared on Earth the first algae 450 million years ago — the higher plants. The appearance of the first invertebrates relates to the ediacaran period (541-635 million years BC) and the emergence of the first vertebrates to Cambrian explosion (525 million years ago). Then life continued to evolve, despite several periods of mass extinction due to various cataclysms that shook the planet.
The earth never was lifeless?
“Twenty years ago it would have been considered heresy; to find evidence of life 3.8 billion years of age was a shock, commented Harrison. — Life on Earth could begin almost immediately. Provided the necessary ingredients, life seems to have formed very quickly.”
Elizabeth bell, who is also involved in the study believed that the Earth originally was not so dry, the conditions on earth were much closer to the present than you can imagine. So what about the theory of “lifeless planet” can be forgotten.
Life on Earth can exist from the start
