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Snakes helped us evolve - article

ArpeggioAngel

Around Here Somewhere....
Read this in the news today. Sounds like a viable theory to me.

WASHINGTON (Reuters) - Snakes may make people jump for a good reason -- human close-up vision may have evolved specifically to spot the reptiles, researchers reported on Thursday.

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Humans, monkeys and other primates have good color vision, large brains, and use their vision to guide reaching and grasping.

But while some scientists believe these characteristics evolved together as early primates used their hands and eyes to pick fruit and other foods, Lynne Isbell, a professor of anthropology at the University of California Davis, believes they may have evolved to help primates evade snakes.

"A snake is the only predator you really need to see close up. If it's a long way away it's not dangerous," said Isbell, who has published her theory in the Journal of Human Evolution.

Neurological studies show the structure of the brain's visual system seems to be well connected to brain structures involved in vigilance, fear and learning, she said.

Mammals evolved about 100 million years ago and fossils of snakes with mouths big enough to eat those mammals appear at about the same time, she pointed out.

Other predators such as big cats, and hawks and eagles, evolved later. And then venomous snakes evolved about 60 million years ago, which forced primates to get better at detecting them.

"There's an evolutionary arms race between the predators and prey. Primates get better at spotting and avoiding snakes, so the snakes get better at concealment, or more venomous, and the primates respond," Isbell said.

And there are no dangerously venomous snakes on Madagascar, and lemurs, which only live on that large island and which have poor eyesight, have not evolved much in other ways in the past 60 million years, either, Isbell added.
 
Very interesting. I'm always amazed that despite my lack of fear of colubrids, I can still have a fairly strong startle-response to an obvious (if negligible) threat. But I guess it gives me little comfort to think that I'm not really a wuss, but just primitive. :awcrap: :grin01:
 
Agreed. Very interesting. :) And I know what you mean, Roy. You're not the only one.

-Kat
 
Cool article. An interesting take on things. I'm surprised there's no mention of learning. There seems to be a lot of support for learned behavior to be responsible for many species responses to different environmental (predator) threats.
 
I'm always amazed that despite my lack of fear of colubrids, I can still have a fairly strong startle-response to an obvious (if negligible) threat.

I totally agree. I love snakes, always have...but if I am walking down a wooded path and one should happen to shoot out in front of me, my knee jerk reaction has always been to jump/run. Once I am over that, the curiousity takes over.

Now spiders on the other hand...doesn't matter if I see them first or they see me first. I always run/hide/scream....I am terrified of the little (or large!) buggers!
 
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