Life on Earth may have evolved much earlier than previously believed

Washington, Feb 6 (ANI): Biochemists at the Monash University in Australia have found a critical piece in the evolutionary puzzle that explains how life on Earth evolved much earlier in the evolutionary timeline than previously believed.

The team, from the School of Biomedical Sciences, has described the process by which bacteria developed into more complex cells and found this crucial step happened much earlier in the evolutionary timeline than previously thought.

According to team leader Trevor Lithgow, the research explained how mitochondria - the power house of human and other cells, which provide complex eukaryotic cells with energy and ability to produce, divide and move - were thought to have evolved about 2000 million years ago from primitive bacteria.

"We have now come to understand the processes that drove cell evolution. For some time now the crux of this problem has been to understand how eukaryotes first came to be," Professor Lithgow said.

"The critical step was to transform small bacteria, passengers that rode within the earliest ancestors of these cells, into mitochondria, thereby beginning the evolution of more complex life-forms," he added.

The team found that the cellular machinery needed to create mitochondria was constructed from parts pre-existing in the bacterium.

These parts did other jobs for the bacterium, and were cobbled together by evolution to do something new and more exciting. "Our research has crystallised with work from other researchers around the world to show how this transformation happened very early on - that the eukaryotes were spawned by integrating the bacterium as a part of themselves. This process jump-started the evolution of complex life much more rapidly than was previously thought," said Professor Lithgow.

The research consisted of two components, the first used computers to read, compare and understand DNA sequences.

From this, experiments were designed to do actual laboratory testing using a bacterium that is the closest living relative to the original ancestor of the mitochondria.

"We can now "read" with great care and insight genome sequences - the complete DNA sequence of any organism. From these sequences we find tell-tale clues to the past. Our findings are relevant to all species, including the evolution of humans," Professor Lithgow said.

"It continues to amaze that this theory, proposed in the century before the advent of molecular investigations, is so accurate on a molecular scale. This improved understanding is directly elevant to the big picture timeline for the evolution of life," he added. (ANI)