Earliest ancestor of all known life emerged within 400 million years of birth of SunNew research indicates that LUCA, the Last Universal Common Ancestor emerged 4.2 billlion years ago.
An illustration of LUCA fighting viruses 4.2 billion years ago.
The research allowed the scientists to determine that LUCA emerged about 4.2 billion years ago, within 400 million years of the formation of the Sun and the Earth.
The researchers were surprised to discover just how early life emerged on Earth.
Scientists surprised by how quickly life emerged on EarthA paper describing the research has been published in Nature Ecology & Evolution.
Earliest ancestor of all known life emerged within 400 million years of birth of Sun
New research indicates that LUCA, the Last Universal Common Ancestor emerged 4.2 billlion years ago.
An illustration of LUCA fighting viruses 4.2 billion years ago. (Image Credit: UCL/Science Graphic Design).
New Delhi: About 4.3 billion years ago, an embryonic Sun began to produce energy through nuclear fusion, marking the birth of the star. All the planets in the Solar System, including the Earth were assembled in the circumstellar disc, a ring of material falling inwards into the Sun. An international team of researchers have compared the genomes of living species, to count the mutations that emerged since LUCA, or the Last Universal Common Ancestor of all life on Earth. The research allowed the scientists to determine that LUCA emerged about 4.2 billion years ago, within 400 million years of the formation of the Sun and the Earth.
LUCA is the ancestor of all modern cellular life, from microscoping bacteria to the ginormous Blue Whale. LUCA sits at the root of the tree of life, before it split into the three major groups recognised today, Bacteria, Archaea and Eukarya. All life on Earth today use the same amino acids to build proteins, and share the energy currency of ATP, as well as storing genetic information in DNA. The researchers were surprised to discover just how early life emerged on Earth.
Scientists surprised by how quickly life emerged on Earth
A paper describing the research has been published in Nature Ecology & Evolution. Coauthor of the paper, Graham Shields says, “This fact that life’s common ancestor lived so early on was quite a surprise and points to a much earlier origin for life itself. This contradicts a widely held notion among scientists that meteorite impacts rendered our planet sterile throughout the first half billion years of its existence.”
The researchers also discovered that LUCA was a complex organism, not very different from modern prokaryotes, and that it clearly possessed an immune system, demonstrating that our common ancestor was engaging in an arms race with viruses 4.2 billion years ago, suggesting a thriving ecosystem. The waste products of LUCA would have been food for other microbes, such as methanogens.
