Biochemists find key to riddle of life

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Researchers from Monash University School of Biomedical Sciences, described the process by which bacteria developed into more complex cells and found this crucial step happened much earlier in the evolutionary timeline than suspected.

Trevor Lithgow, who led the study, explained how mitochondria, which powers human and other cells and provides complex eukaryotic cells with energy and ability to produce, divide and move, were thought to have evolved about 2,000 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," Lithgow added.

"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," Lithgow said.

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, said a Monash release.

"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," concluded Lithgow.

The research was published in Science.