Article: Snakes influence on primate evolution

[Spaniard]

Found this article in a magazine I read. So credit goes to The Week. Sorry but my scanner at work doesn't do color, but hopefully you'll recognize the sillouette. Kind of an interesting theory. I linked my photo bucket account because when I inserted the pic here it was unreadable.

http://s47.photobucket.com/albums/f1...gAnch=imgAnch1

[Ginevive]

Couldn't mistake that silhouette anywhere
I think snakes are like anything else to a prey animal; something fast and unfamiliar looking is something to run from. Now, take humans; we are equipped with the ability to reason and think things out (not that we use it all the time!) So instead of running like, say, a deer would when approached by a snake, I would think our ancestors either tried to kill/eat it, grab/observe it, or just ignored it and moved on. Now, when someone had gotten bitten by one, that would be a negative and painful experience; let's say that ancestor was walking by with their young child and saw a snake; they would then grab the kid and run, teaching the kid that the snake was to be feared.
It really is no wonder snakes got this bad rep; if I were a primitive person and my grandma was bitten and died frrom a snakebite, my brain's logical response would probably be to hate snakes... years and years of this have led to the hatred I think.

[elevatethis]

I think its a stretch to say that snakes are the sole cause of the evolution of certain traits in early primates...were they a factor, sure, but that article doesn't mention anything else and takes a firm stand on it being snakes and snakes alone.

If people evolved to have an irrational fear of snakes, why do some cultures in africa and asia worship them and consider snakes in their homes a blessing?

[Mendel's Balls]

If people evolved to have an irrational fear of snakes, why do some cultures in africa and asia worship them and consider snakes in their homes a blessing?

Because humans have a well-developed ceberal cortex that can override many of the neurological fear pathways in other parts of our brain.

The snake-primate coevolution hypothesis deals with the evolution of the visual system of old world derived primates as much as it does with their instinctual fear responses. I think this article has it much better than the one on livescience.....http://news.mongabay.com/2006/0720-davis.html...
notice how one of the core predictions of the hypothesis bears out....new world monekys dont have as developed visual system because they dont have as long of an evolutionary exposure to venomous snakes.

Interestingly, old-world monkeys appear to have fear pathways strongly associated with their visual system.

The Journal of Evolution paper lists the following citation......

interesting how rhesus monkeys were able to be easily conditioned to be fearful towards a spliced video tape showing other monkeys being scared of a snake.....but not to flowers.

It good to be skeptical of a new hypothesis......just remember that science journalists rarely give you the data or the reasons that set up and support the idea.

[elevatethis]

Because humans have a well-developed ceberal cortex that can override many of the neurological fear pathways in other parts of our brain.

So are you saying that snake keepers have a more well-developed cerebral cortex than people who don't like snakes???

I like it!!

[Mendel's Balls]

So are you saying that snake keepers have a more well-developed cerebral cortex than people who don't like snakes???

I like it!!

Exactly......lol

[Spaniard]

I definitely do not think that snakes alone were the cause for the honing of vision in old world primates, but the fact that they could be a major contributor doesn't seem far fetched. I don't know much about venomous snakes but I think they're usually pretty colorful which would explain the development of seeing in color. For those species of venomous snakes which were not brightely colored I would imagine that acute vision would be really important to spot them out in their natural environments while foraging for food.

interesting how rhesus monkeys were able to be easily conditioned to be fearful towards a spliced video tape showing other monkeys being scared of a snake.....but not to flowers.

So I guess the rhesus monkeys were either instinctually responding with fear to the toy snakes or knew that the flower was not a threat. I know that would be a rational thought coming from a monkey, but you never know for sure what it is they're exactly thinking.

Both articles were none the less very interesting. The fact that animals with no venomous snakes in the area experienced less evolutionary growth in their visual systems is also very interesting.

[Spaniard]

So are you saying that snake keepers have a more well-developed cerebral cortex than people who don't like snakes???

I like it!!

You mean we're not just all weirdos like the general public thinks! Awesome.