Loading...

The Human Brain Is Decreasing Over Time!

17,499 views

Loading...

Loading...

Transcript

The interactive transcript could not be loaded.

Loading...

Loading...

Rating is available when the video has been rented.
This feature is not available right now. Please try again later.
Uploaded on Apr 30, 2010

Evolution in humans is commonly thought to have essentially stopped in recent times. But there are plenty of examples that the human race is still evolving, including our brains, and there are even signs that our evolution may be accelerating.

Shrinking brains

Comprehensive scans of the human genome reveal that hundreds of our genes show evidence of changes during the past 10,000 years of human evolution.
"We know the brain has been evolving in human populations quite recently," said a paleoanthropologist.
Surprisingly, based on skull measurements, the human brain appears to have been shrinking over the last 5,000 or so years.

"When it comes to recent evolutionary changes, we currently maybe have the least specific details with regard the brain, but we do know from archaeological data that pretty much everywhere we can measure — Europe, China, South Africa, Australia — that brains have shrunk about 150 cubic centimeters, off a mean of about 1,350. That's roughly 10 percent," the paleoanthropologist said.

"As to why is it shrinking, perhaps in big societies, as opposed to hunter-gatherer lifestyles, we can rely on other people for more things, can specialize our behavior to a greater extent, and maybe not need our brains as much," he added.

Later in the video and shown from different perspectives is an 8 centimeter high carving of a human face on mammoth ivory that has been dated to 26,000 years ago. A number of human likenesses carved, like this one on mammoth ivory, have been found in central Europe but none so intricate. The object shown here is the oldest portrait of a human yet discovered. It shows exquisite details of the subject, including eyes, hair, mouth, and expression. According to anthropologists whove studied the skulls of the humans of this period, they had bigger brains and more robust skulls, as well as heavier brow ridges and jaws, and thicker noses. These traits are typical of archaic skulls as seen here. The average prognathism in the Paleolithic samples is also greater than in modern populations, and probably has a lot to do with the much larger teeth humans had prior to the Neolithic farming revolution. Other art objects from around this period also show the early Europeans represented with straight hair.

Loading...

When autoplay is enabled, a suggested video will automatically play next.

Up next


to add this to Watch Later

Add to

Loading playlists...