(NLDO) - This creature that scientists call "the last common ancestor of the universe" lived 4.2 billion years ago.
According to Sci-News, a group of scientists from the University of Bristol (UK) has succeeded in finding the "last universal common ancestor" (LUCA), a hypothetical ancestor of all organisms on Earth and possibly many other planets.
LUCA is the top node of the terrestrial ecosystem, from which early life forms including bacteria and archaea diverged.
A strange, more complex life form than we thought came to Earth and became the common ancestor of all species? - Photo AI: ANH THU
As widely accepted theories of the origin of life on Earth suggest, after our planet formed, the first lifeforms "traveled" from space via meteorites and comets.
Over billions of years, those lifeforms evolved into the entire biological world today.
What did that first life look like, was it a life form or just primitive prebiotic material? LUCA could be that life.
In the new study, University of Bristol scientist Edmund Moody and colleagues compared all the genes in the genomes of living species, counting the mutations that occurred in their sequences over time.
The divergence times of several species are known from the fossil record, allowing researchers to use a genetic equation equivalent to the familiar equation used to calculate speeds in physics to figure out when LUCA existed.
The results show that LUCA lived 4.2 billion years ago, 400 million years after the Earth formed.
Co-author Dr Sandra Álvarez-Carretero said they had not expected this common ancestor to be so old.
However, this result is consistent with modern views of habitability on early Earth.
Previously, it was thought that it was not until the Hadean eon ended 3.8 billion years ago that Earth was no longer a ball of fire and life began to form.
However, some recent evidence in Australia suggests signs of organic material likely originating from microorganisms, "sealed" in rocks that are 3.8-4.1 billion years old.
The Bristol team's research also shows that LUCA was a complex organism, not too different from modern prokaryotes, but what's really interesting is that it apparently possessed an early immune system.
LUCA has exploited and modified its environment, but is incapable of living alone. It relies on the organisms it generates. Its waste will also feed other bacteria, helping to create a recycling ecosystem.
According to co-author Professor Philip Donoghue, LUCA has demonstrated how quickly ecosystems formed on early Earth.
This also suggests that life could thrive on Earth-like biospheres elsewhere in the vast universe.
The study was recently published in the scientific journal Nature Ecology & Evolution.
Source: https://nld.com.vn/lo-dien-to-tien-chung-cua-chung-ta-va-sinh-vat-ngoai-hanh-tinh-196240714100132206.htm
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