Draft and notes. I've hightlighted some of the article's main ideas.
If you examine evolutionary lineage to trace where the evolution of humankind, about one million years ago, you'll notice two branches. One branch goes extinct, the other is a part of the branch leading to humans.
From the fossil record, the physiology of those two branches appear to be very similar. So why did one branch die and the other flourish. Scientists believe they may have found the answer.
The branch that flourished exhibited cooperation. The other did not.
Seems a bit of a leap to make this ascertain, though computer modeling makes an interesting illustration of the hypothesis.
Did early humans socialize to avoid getting eaten?
- 12:06 21 February 2006
- NewScientist.com news service
- Roxanne Khamsi, St Louis
New computer simulations lend further support the notion that cooperation helped early humans escape becoming prey for other animals, researchers report.
The work suggests that teamwork could have given Australopithecus – a group of hominids closely related to humans – an important advantage over their cousins Paranthropus, contributing to their extinction.
The unpublished experiments, conducted by Augustin Fuentes at the University of Notre Dame in South Bend, Indiana, US, and colleagues, were presented at the annual meeting of the American Association for the Advancement of Science in St Louis, Missouri, US.
Australopithecus and Paranthropus lived more than one million years ago. "We know Paranthropus goes extinct," says Fuentes. "But we don't know why."
He speculated that Paranthropus suffered from increased predation because Australopithecus, and other early humans even more closely related to modern humans, learned to use cooperation to avoid being eaten. He says all would have feared the same predators, such as big cats. Stone tools
To test the hypothesis, Fuentes's team designed a computer program based on classic ecology models to simulate how teamwork could have tipped the scales in favour of Australopithecus. They found that just a moderate amount of teamwork gave Australopithecus a dramatic advantage over its close competitors, causing the extinction of Paranthropus.
The computer simulations add to real world evidence of co-operation in early humans. For example, the common use of stone tools by early humans suggests they shared information on the location of suitable stone. These sites are sometimes 30 kilometres away from where the tools are found and would not have been easy for individuals to find on their own.
"This implies some sort of information transfer that's not language yet, but is much more extensive than that available to other organisms," Fuentes says.
He also notes there is hard evidence that early humans were preyed upon, such as holes in skulls that match the size of sabre-toothed cat's fangs. "Then we find that, especially in South Africa, a lot of the fossils are in these big piles in caves where predators dragged and dropped them," he says.