Who would have suspected that a handheld genetic test used to unmask sushi bars pawning off tilapia for tuna could deliver deep insights into evolution, including how new species emerge?
And who would have thought to trawl through five million of these gene snapshots—called “DNA barcodes”—collected from 100,000 animal species by hundreds of researchers around the world and deposited in the US government-run GenBank database?
That would be Mark Stoeckle from The Rockefeller University in New York and David Thaler at the University of Basel in Switzerland, who together published findings last week sure to jostle, if not overturn, more than one settled idea about how evolution unfolds.
It is textbook biology, for example, that species with large, far-flung populations—think ants, rats, humans—will become more genetically diverse over time.
But is that true?
“The answer is no,” said Stoeckle, lead author of the study, published in the journal Human Evolution.
For the planet’s 7.6 billion people, 500 million house sparrows, or 100,000 sandpipers, genetic diversity “is about the same,” he told AFP.
The study’s most startling result, perhaps, is that nine out of 10 species on Earth today, including humans, came into being 100,000 to 200,000 years ago.
“This conclusion is very surprising, and I fought against it as hard as I could,” Thaler told AFP.
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