In an astonishing finding, scientists have discovered a microorganism that has remained unchanged for the past two billion years. Some researchers say that the sulphur cycling microorganism found in Australia could have easily been the prime contender for holding Guinness World Record for not evolving.
Scientists were examining the micro-organisms that are too small to be seen by naked eyes when they found the species. They collected samples from rocks in the coastal area; then they collected the sample from a rock 2.3 billion-year-old near the same region. They were astonished, when they matched the species found in both the rock samples. The results obtained from both the samples were mind boggling. Both the sets of microorganism were indistinguishable from each other. This gave birth to the notion that the sulphur bacteria hasn’t evolved in past 2 billion years, successfully surviving five mass extinction events.
“It seems astounding that life has not evolved for more than 2 billion years — nearly half the history of the Earth. Given that evolution is a fact, this lack of evolution needs to be explained,” said J. William Schopf, a UCLA professor of earth, planetary and space sciences in the UCLA College who was the study’s lead author.
The finding confronts the Charles Darwin’s theory of evolution by natural selection which states that a species needs to evolve throughout his lifetime to survive. However, the study authors protected Darwin’s theory and said that the theory doesn’t say that a successful species always needs to evolve. A species evolves only when surroundings and physical changes occur, and only successful mutation passes on to the next generation.
“The rule of biology is not to evolve unless the physical or biological environment changes, which is consistent with Darwin. These microorganisms are well-adapted to their simple, very stable physical and biological environment. If they were in an environment that did not change but they nevertheless evolved, that would have shown that our understanding of Darwinian evolution was seriously flawed.” said Schopf, who also is director of UCLA’s Center for the Study of Evolution and the Origin of Life.
The species reproduce asexually means very little need of evolution apart from it sulphur and nitrate required for their survival was easy available in bulk, thus eliminating the need for any development.
The research was published in the Proceedings of the National Academy of Sciences.