Evolution-schizophrenia linkage found

BATH, England, Sept. 6 (UPI) -- British-led researchers said they found a linkage between evolution and the development of schizophrenia.

The scientists said they found evidence of positive selection, also known as Darwinian selection, in several genes associated with schizophrenia. Darwinian selection is the process by which new variants of genes become dominant because organisms with the new versions are more likely to survive.

The researchers -- Steve Dorus of the University of Bath, Bernard Crespi of Canada’s Simon Fraser University and Kyle Summers of East Carolina University -- said they believe their finding helps explain the persistence of schizophrenia, despite its adverse effects on health and reproductive fitness.

About 1 percent of people suffer from schizophrenia.

"The world-wide presence of this disorder at an appreciable frequency, despite its impact on human health and reproductive fitness, is somewhat of a paradox," said Dorus, adding the persistence of schizophrenia would be understandable if the condition was a by-product of other adaptive changes during human evolution.

"Our finding that positive evolutionary processes have impacted genes underlying the disorder is consistent with this idea," he said.

The study appears in the Proceedings of the Royal Society B.