Two studies show that the effects of nature and nurture are assumed to be clearer than they really are:
The genetics of simple traits can often be deduced from pedigrees, and people have been using that approach for millennia to selectively breed vegetables that taste better and cows that produce more milk. But many traits are not the result of a handful of genes that have clear, strong effects; rather, they are the product of tens of thousands of weaker genetic signals, often found in noncoding DNA. When it comes to those kinds of features — the ones that scientists are most interested in, from height, to blood pressure, to predispositions for schizophrenia — a problem arises. Although environmental factors can be controlled in agricultural settings so as not to confound the search for genetic influences, it’s not so straightforward to extricate the two in humans. …“The new studies are really quite disconcerting,” Barton said, because they demonstrated that scientists had been mistaking biases in the polygenic score calculations for something biologically interesting. Their statistical methods of accounting for population structure were not so adequate after all…
Though it was always understood to be a problem, “no one realized how big of a problem it was,” said Shamil Sunyaev a computational geneticist at Harvard Medical School who performed one of the new eLife analyses…
“It was just that sort of feeling where the world shifts under your feet slightly,” said Coop, who with Berg and their colleagues coauthored the other eLife paper to try to confirm their earlier research. “It’s fairly humbling to see all of that work go away.” …
Barton agreed. “The whole thing is tricky, because the origins of genetic variation in any population are really complicated,” he said. “Now you really can’t take at face value any of these methods over the last four or five years that use polygenic scores.”Jordana Cepelewicz, “New Turmoil Over Predicting the Effects of Genes” at Quanta
Not to worry, if it’s a big enough mess, it will fit right in.
Hat tip: Heather Zeiger
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See also: Protein turns jumping genes, once considered “junk DNA,” from “foes into friends” What? It needs managing but it isn’t junk. “Our results reveal how a family of proteins that was long considered an oddity of nature, turns foes into friends,” says Didier Trono. And almost nothing the Darwinians told us is true.