Human evolution occurred ‘3mn yrs earlier than previously thought’

WASHINGTON - A new statistical model has suggested that evolutionary divergence of humans from chimpanzees likely occurred some 8 million years ago rather than the 5 million year estimate widely accepted by scientists.

The revised estimate of when the human species parted ways from its closest primate relatives should enable scientists to better interpret the history of human evolution, said Robert D. Martin, curator of biological anthropology at the Field Museum, and a co-author of the new study.

By looking at all of today’s primate species, all of the known fossil primates and using DNA evidence, computer models suggest a longer evolutionary timetable.

Such modeling techniques, which are widely used in science and commerce, take into account more overall information than earlier processes used to estimate evolutionary history using just a few individual fossil dates, Martin said. It can give scientists a broader perspective for interpreting data.

The new approach to dating evolutionary history builds on earlier work by Martin and colleagues.

This implies that for 20 million years before dinosaurs became extinct, early versions of primates also lived and evolved. It challenged the accepted theory that primates and other mammals didn’t really thrive on the planet until dinosaurs were gone.

After that paper was published, Martin said he expected someone would apply the new statistical techniques to the question of human evolution, but when no one did, “We decided to do it ourselves.”

The report has been published in the journal Systematic Biology. (ANI)