Scientists say tiny structural flaws in proteins may have been responsible for changes, which sparked complex life, a claim that suggests natural selection isn’t only means by which higher organisms came into being.

A comparison of proteins across 36 modern species suggests that protein errors called “dehydrons” may have made proteins less stable in water. This would have made them more adhesive and more likely to end up working together, building up complex function, say the scientists.

Michael Lynch, an evolutionary theorist at Indiana University, who teamed up with Ariel Fernandez of University of Chicago, looked specifically at protein structure for their research published in the Nature journal.

“It’s opening up a new evolutionary pathway that didn’t exist before,” he said. The scientists considered 106 proteins shared among 36 modern-day organisms of widely varying complexity, from single-celled protozoa up to humans. They were studying “dehydrons” — regions of proteins that make them more unstable in watery environments.

These dehydrons make the proteins stickier in water, thereby raising the probability that they will adhere to other such proteins. “We’ve opened up the idea that roots of complexity don’t have to reside in purely adaptational arguments,” Lynch was quoted by the BBC as saying.

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