close
Advertisement
Can't connect right now! retry

add The News to homescreen

tap to bring up your browser menu and select 'Add to homescreen' to pin the The News web app

Got it!

add The News to homescreen

tap to bring up your browser menu and select 'Add to homescreen' to pin the The News web app

Got it!
AFP
August 23, 2019

Ancient monkey skull reveals secrets of primate brain evolution

World

AFP
August 23, 2019

The remains of a prehistoric primate that lived high in the Andes 20 million years ago and was so small it could fit in your hand is helping scientists learn more about how human brains evolved.

In a study published Wednesday in the journal Science Advances, researchers in China and the US used high resolution imaging to examine the only known fossilized skull of the extinct Chilecebus, a New World monkey that scampered around ancient mountain forests, feeding on leaves and fruit.

One key finding: the brain size of primates, long assumed to have increased progressively over time, now appears to have followed a more roundabout path. Primates are broadly split into two groups: Old World, from which our own species descended, and New World species of the Americas and Oceania.

"We see multiple episodes of expansion of the brain in each of these major groups, and we see several episodes of actual reduction of relative brain size in certain groups," co-author John Flynn of the American Museum of Natural History told AFP.

The research, led by Xijun Ni, at the Chinese Academy of Sciences, used X-rays and CT scans of the inside of the Chilebus’ skull to determine its internal structure. The fossilized skull has been precisely dated because it was discovered among volcanic rocks, and by placing the species within its bigger family tree, the team was able to infer that cerebral enlargement occurred repeatedly and independently in anthropoid evolution.

Though the Chilecebus was roughly around the size of a modern marmoset or tamarin, in contrast to those monkeys its brain had several grooves known as infolding that suggest a greater degree of cognitive complexity: in other words, brain size is not always linked to advancement.

What’s more, in modern primates, the size of the visual and olfactory centres of the brain are inversely related, meaning that species with a strong sense of sight usually have a weaker sense of smell and vice versa.

Topstory minus plus

Opinion minus plus

Newspost minus plus

Editorial minus plus

National minus plus

World minus plus

Sports minus plus

Business minus plus

Karachi minus plus

Lahore minus plus

Islamabad minus plus

Peshawar minus plus