Dharamshala, 10th February: A new study led by a group of researchers from Israel and Ghana has found the first evidence of nonrandom mutation in human DNA, posing a challenge to evolutionary theory by demonstrating a long-term directional mutational response to environmental pressure.

Researchers led by Professor Adi Livnat of the University of Haifa used a novel way to show that the rate of creation of the HbS mutation, which protects against malaria, is higher in persons from Africa than in people from Europe, where malaria is not widespread. “Random mutations have been the leading theory of evolution for nearly a century.”

We’ve known since Darwin that life is the result of evolution. But how does evolution — in all of its splendor, mystery, and intricacy – take place? For almost a century, scientists have assumed that genome changes happen by chance and that natural selection, or survival of the fittest, favors favorable mutations. From the hawk’s acute eye to the human cardiovascular system, the accumulation of these assumed genetic accidents under natural selection over millennia leads to adaptations.

Despite its widespread acceptance in the scientific community, this viewpoint has always left important concerns unanswered, such as the complexity problem. Can the accumulation of small random changes, each of which is beneficial on its own, lead to the evolution of such astonishingly complex and impressive adaptations as we see in nature, such as eyes, brains, or wings, where complementary parts interweave into a complex whole, within the timeframe available?

At the most fundamental level, however, the only alternative developed up until now was variations of Lamarckism – the belief that organisms can adapt immediately to their immediate circumstances with beneficial genetic change. Because Lamarckism hasn’t worked in general, the idea of random mutation has remained popular.

Prof. Livnat and his lab manager, Dr. Daniel Melamed, developed a new method for detecting de novo mutations – mutations that arise “out of the blue” in offspring without being inherited from either parent – in order to distinguish between the random mutation and natural selection explanation and the possibility that nonrandom mutation is important. Their method, which set a new accuracy record, allowed them to do something that had never been done before: count de novo mutations for specific points of interest in the genome.

Until now, researchers could only measure mutation rates as averages across several places in the genome due to technological limitations. Overcoming this stumbling block, Livnat and Melamed’s novel method allowed the HbS mutation to be the first to have its mutation-specific origination rate determined, opening up new avenues for mutation research. This research has the potential to change not only how we think about evolution, but also how we think about diseases induced by mutations, such as cancer and a genetic disorder.

The article was published in Genome Research, a scientific journal.

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