Posted on 07/20/2006 6:58:11 AM PDT by PatrickHenry
The ability to spot venomous snakes may have played a major role in the evolution of monkeys, apes and humans, according to a new hypothesis by Lynne Isbell, professor of anthropology at UC Davis. The work is published in the July issue of the Journal of Human Evolution.
Primates have good vision, enlarged brains, and grasping hands and feet, and use their vision to guide reaching and grasping. Scientists have thought that these characteristics evolved together as early primates used their hands and eyes to grab insects and other small prey, or to handle and examine fruit and other foods.
Isbell suggests instead that primates developed good close-up eyesight to avoid a dangerous predator -- the snake.
"A snake is the only predator you really need to see close up. If it's a long way away it's not dangerous," Isbell said.
Neurological studies by others show that the structure of the brain's visual system does not actually fit with the idea that vision evolved along with reaching and grasping, Isbell said. But the visual system does seem to be well connected to the "fear module," brain structures involved in vigilance, fear and learning.
Fossils and DNA evidence show that snakes were likely the first serious predators of modern mammals, which evolved about 100 million years ago. Fossils of snakes with mouths big enough to eat those mammals appear at about the same time. Other animals that could have eaten our ancestors, such as big cats, and hawks and eagles, evolved much later.
Venomous snakes evolved about 60 million years ago, raising the stakes and forcing 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.
Some primate groups less threatened by snakes show fewer signs of evolutionary pressure to evolve better vision. For example, the lemurs of Madagascar do not have any venomous snakes in their environment, and in evolutionary terms "have stayed where they are," Isbell said. In South America, monkeys arrived millions of years before venomous snakes, and show less specialization in their visual system compared with Old World monkeys and apes, which all have good vision, including color.
Having evolved for one purpose, a good eye for color, detail and movement later became useful for other purposes, such as social interactions in groups.
Isbell is currently working on a book about primate origins, including her snake hypothesis.
Why do you ask?
I am saying they build hypotheses upon hypotheses. I assume they get the idea by looking at moneys and snakes in the wild, and say, "Ah hah." Al; they are doing is promoting one possibility over other. Do they even know the relative number of primates and snakes at the time?
"Ooooh! Can I answer? As a newly born YECCer, let me be the first to say: Goddidit."
Wow. I am astounded. Tell me how. Give details.
I thought that was a matter of faith. Do you have multiple sources of evidence for this?
Because it's topic jumping and a distraction.
Having an IF statement that could potentially cause a GOTO out of a GOSUB subroutine will invariablly lead to a memory leak. This could explain why creationists that their repeatedly-made have been debunked more than once.
Sue me
Maybe that's why there are so many gaps in the fossil record. Sloppy programming.
Based on multiple witnesses we know for a fact that big-eyed, gray-skinned aliens are likely to abduct you at any moment for the purpose of filming interspecies porn.
That's what Jesus would say.
Is it okay if I judge the credibility of the witnesses?
"From a judicial point of view I can point you to the Historical evidence of the resurrection of Jesus Christ as a proof text of supernatural reality."
That had to be the most amazing thing that has ever happened in the history of man. How long after the fact did someone write about it? Answer 40-130 years later. Why? If I saw that, I'd go home and write a book on the spot.
Sorry, the actual witnesses are not available. You will have to judge their reliability based on what I say.
Ha ha! That's quite a heavy load to carry there, S2R!
"Sorry, the actual witnesses are not available. You will have to judge their reliability based on what I say."
Ok, judgement has arrived. B.S. Case closed.
But think about this. If you deny my story and are wrong, you will suffer eternal torment. Not a good bet.
Ablatives? Binomial names are usually a noun and adjective: Homo sapiens, Didelphis virginiana, Boa constrictor, Canis lupus familiaris
"But think about this. If you deny my story and are wrong, you will suffer eternal torment. Not a good bet."
I deny your story. I don't bet. Religion is a tactic to control people. And by design, it ends up controlling weak minded people. I guess I have never done anything that makes me feel really guilty. I guess some people are always on the edge of doing something ridiculously stupid or immoral, so they need some supernatural protection. When I do something stupid, I just look the person in the eye and apologize.
Not only that, but no one but the authors of the Gospels mention it. Israel was a pretty literate society at that time, and there were, of course, the Romans who recorded everything under the sun. Neither of these groups found the time to mention this monumental event, nor the supposed earthquake, darkening of the sky, and the dead walking the Earth that accompanied Jesus' death.
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