Washington, Dec 18 (ANI): A ground-breaking study has characterized the common ancestor of all life on Earth as LUCA (Last Universal Common Ancestor), a 3.8-billion-year-old organism, which challenges the intelligent design theory about Adam and Eve being humanity's predecessors.
The study, conducted by a team of evolutionary geneticists from the Universite de Montreal, shows that the LUCA was not the creature usually imagined.
"It is generally believed that LUCA was a heat-loving or hyperthermophilic organism. A bit like one of those weird organisms living in the hot vents along the continental ridges deep in the oceans today (above 90 degrees Celsius)," said Nicolas Lartillot, the study's co-author and a bio-informatics professor at the Universite de Montreal.
"However, our data suggests that LUCA was actually sensitive to warmer temperatures and lived in a climate below 50 degrees," he added.
The research team compared genetic information from modern organisms to characterize the ancient ancestor of all life on earth.
"Our research is much like studying the etymology of modern languages so as to reveal fundamental things about their evolution," said professor Lartillot.
"We identified common genetic traits between animals, plant, bacteria, and used them to create a tree of life with branches representing separate species. These all stemmed from the same trunk - LUCA, the genetic makeup that we then further characterized," he explained.
The group's findings are an important step towards reconciling conflicting ideas about LUCA.
In particular, they are much more compatible with the theory of an early RNA (ribonucleic acid) world, where early life on Earth was composed of RNA, rather than deoxyribonucleic acid (DNA).
However, RNA is particularly sensitive to heat and is unlikely to be stable in the hot temperatures of the early Earth.
The data of Dr. Lartillot, with his collaborators, indicate that LUCA found a cooler micro-climate to develop, which helps resolve this paradox and shows that environmental micro domains played a critical role in the development of life on Earth.
"It is only in a subsequent step that LUCA's descendants discovered the more thermostable DNA molecule, which they independently acquired (presumably from viruses), and used to replace the old and fragile RNA vehicle," he said.
"This invention allowed them to move away from the small cool microclimate, evolved and diversify into a variety of sophisticated organisms that could tolerate heat," he added. (ANI)