Posted on 02/19/2006 12:18:49 PM PST by blam
Predators 'drove human evolution'
By Paul Rincon
BBC News science reporter, St Louis
The alternative view that man was the one hunted was suggested
The popular view of our ancient ancestors as hunters who conquered all in their way is wrong, researchers have told a major US science conference.
Instead, they say, early humans were on the menu for predatory beasts.
This may have driven humans to evolve increased levels of co-operation, according to their theory.
Despite humankind's considerable capacity for war and violence, we are highly sociable animals, according to anthropologists.
James Rilling at Emory University in Atlanta, US, has been using brain imaging techniques to investigate the biological mechanisms behind co-operation.
He has imaged the brains of people playing a game under experimental conditions that involved choosing between co-operation and non-co-operation.
From the parts of the brain that were activated during the game, he found that mutual co-operation is rewarding; people reacted negatively when partners did not co-operate.
Dr Rilling also discovered that his subjects seemed to have enhanced memory for those people that did not reciprocate in the experiment.
Man 'the hunted'
By contrast, our closest relatives - chimpanzees - have been shown not to come to the aid of others, even when it would pose no cost to themselves.
"Our intelligence, co-operation and many other features we have as modern humans developed from our attempts to out-smart the predator," said Robert Sussman of Washington University in St Louis.
According to the theory espoused by Professor Sussman, early humans evolved not as hunters but as prey for animals such as wild dogs, cats, hyenas, eagles and crocodiles.
He points to the example of one ape-like species thought to be ancestral to humans, Australopithecus afarensis.
A. afarensis was what is known as an "edge species"; it could live in trees and on the ground, and could take advantage of both.
"Primates that are edge species, even today, are basically prey species, not predators," Professor Sussman explained.
Hard target
Dr Agustin Fuentes at the University of Notre Dame agrees with the predation hypothesis.
He believes early humans were subject to several evolutionary pressures, including predation.
But he also thinks they were expending more energy at this time and that child-rearing became more demanding.
All these factors contributed to an emergence of sociable behaviour in hominids that made them harder targets for predators.
Dr Fuentes points to fossil evidence of predation in two different groups of humanlike species: Australopithecus and Paranthropus.
The latter group, it appears, could not adapt to pressures such as predation, and became extinct between one and 1.2 million years ago.
The scientists outlined their work at the American Association for the Advancement of Science annual meeting in St Louis,
Well, gee, could that possibly be due to the fact that primates, in general, are not predators.
Ah aims to please...
Except for the one we are.
Implied with the "in general".(Chimps also eat meat, but only rarely --- no pun intended)
They post often enough, but the threads they frequent are prone to getting banished to the Religion forum, or sometimes to the Smoky Backroom forum when things get out of hand. But they also pop up frequently on threads about the currently hot topic of "intelligent design".
Intelligent design will become inarguable when we design robots and send them out into the galaxy.
I worded it that way to avoid argument. However, for the sake of argument, I've never heard anyone explain, if they believe in intelligent design, just where the designer came from, and which entity designed the designer, and so forth.
Our limp rationale that things "just happened" is certainly no worse than the limp rationale that an entity or entities unknown caused them to happen, because then how do you explain that beginning?
I'm not denying the existance of any possibility, or any entity. I simply like to cut to the chase with Occam's razor.
Precisely. Personally I'm a big advocate of including "intelligent design" in school curricula, as long as it's the how-to variety. I'm sure we currently have the ability to engineer various one-celled organisms that could survive and thrive on Mars, and eventually evolve into more complex organisms. Quite possible that we are derived from some such venture, but that has no bearing, as you pointed out, on the question of "how it all started".
Other predators could not be avoided, they would find you. Tigers, cave lions, african lions, bears, hyenas, wolves, etc. Nothing we can do about them except band together and fight and lose the occasional family member. But others are more easily avoided by having half a brain, and that is what we probably had back then.
Not in defense of the study or the premise..just semantics...losely speaking, I believe that a Saber Tooth Tiger would be a "cat." As a Wolf would be a dog. Now an Eagle...
We are talking a region that has frequent droughts, and water holes can be few and far between.
I think the author of the article overemphasizes the role of predation in actually changing us.
Certainly it was one of the pressures mitigating against our survival, but competition for resources would have had a more selective function.
Migration, climactic change, and the need to find alternate forms of nourishment would have had a more direct effect in selecting for intelligence.
Predation was a major driving factor in the evolution of such divers creatures as the sauropods and the armadillo. I'm not certain why it wouldn't be a major fact in human evolution, too.
Predation is a major driving factor in any species' evolution.
My point is that it is not necessarily a major driving factor in making the species more intelligent.
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