"The genetic evolution of humans in the very recent past might in some ways be linked to the cultural evolution," he said.Other scientists urge great caution in interpreting the research.
So suggests new research that tracked changes in two genes thought to help regulate brain growth, changes that appeared well after the rise of modern humans 200,000 years ago.
That the defining feature of humans — our large brains — continued to evolve as recently as 5,800 years ago, and may be doing so today, promises to surprise the average person, if not biologists.
Aside from not knowing what the gene variants actually do, no one knows how precise the model Lahn used to date them is, Collins added.
Lahn's own calculations acknowledge that the microcephalin variant could have arisen anywhere from 14,000 to 60,000 years ago, and that the uncertainty about the ASPM variant ranged from 500 to 14,000 years ago.
"No matter how we [changed] the analysis or assumptions, we couldn't get a date of around 6,000 years," says Gray.