Comments Subscribe to Personal Liberty News Feed Subscribe to Personal Liberty
 

Did Hard-Wired Fear Of Snakes Drive Evolution Of Human Vision?

DAVIS, Calif., Oct. 29 (UPI) — The evolution of high-quality vision in our human ancestors may have been driven by a hard-wired fear of snakes, Japanese and Brazilian researchers suggest.

Writing in the Proceedings of the National Academy of Sciences, the researchers report they found specific nerve cells in the brains of rhesus macaque monkeys that respond to images of snakes.

The snake-sensitive neurons were more numerous, and responded more strongly and rapidly, than other nerve cells that fired in response to images of macaque faces or hands, or to geometric shapes, the researchers said.

“We’re finding results consistent with the idea that snakes have exerted strong selective pressure on primates,” said anthropologist Lynne Isbell of the University of California, Davis, who first proposed the theory being tested by the Japanese and Brazilian researchers.

In a hypothesis first put forward in 2006, Isbell argued our primate ancestors evolved good, close-range vision primarily to spot and avoid dangerous snakes.

Japanese researchers studied the neural mechanisms responsible for emotion and fear in rhesus macaque monkeys, especially instinctive responses that occur without learning or memory.

“The results show that the brain has special neural circuits to detect snakes, and this suggests that the neural circuits to detect snakes have been genetically encoded,” Hisao Nishijo of Toyama University said.

The monkeys in the study were reared in a walled colony and none had previously encountered a real snake, the researchers said.

“I don’t see another way to explain the sensitivity of these neurons to snakes except through an evolutionary path,” Isbell said in a UC Davis release.

UPI - United Press International, Inc.

Since 1907, United Press International (UPI) has been a leading provider of critical information to media outlets, businesses, governments and researchers worldwide.

Facebook Conversations

Join the Discussion:
View Comments to “Did Hard-Wired Fear Of Snakes Drive Evolution Of Human Vision?”

Comment Policy: We encourage an open discussion with a wide range of viewpoints, even extreme ones, but we will not tolerate racism, profanity or slanderous comments toward the author(s) or comment participants. Make your case passionately, but civilly. Please don't stoop to name calling. We use filters for spam protection. If your comment does not appear, it is likely because it violates the above policy or contains links or language typical of spam. We reserve the right to remove comments at our discretion.

Is there news related to personal liberty happening in your area? Contact us at newstips@personalliberty.com

Bottom
close[X]

Sign Up For Personal Liberty Digest™!

PL Badge

Welcome to PersonalLiberty.com,
America's #1 Source for Libertarian News!

To join our group of freedom-loving individuals and to get alerts as well as late-breaking conservative news from Personal Liberty Digest™...

Privacy PolicyYou can opt out at any time. We protect your information like a mother hen. We will not sell or rent your email address to anyone for any reason.