Posted on 02/26/2002 10:50:54 AM PST by dead
On the biggest steps in early human evolution scientists are in agreement. The first human ancestors appeared between five million and seven million years ago, probably when some apelike creatures in Africa began to walk habitually on two legs.
They were flaking crude stone tools by 2.5 million years ago. Then some of them spread from Africa into Asia and Europe after two million years ago.
With somewhat less certainty, most scientists think that people who look like us — anatomically modern Homo sapiens — evolved by at least 130,000 years ago from ancestors who had remained in Africa. Their brain had reached today's size. They, too, moved out of Africa and eventually replaced nonmodern human species, notably the Neanderthals in Europe and parts of Asia, and Homo erectus, typified by Java Man and Peking Man fossils in the Far East.
But agreement breaks down completely on the question of when, where and how these anatomically modern humans began to manifest creative and symbolic thinking. That is, when did they become fully human in behavior as well as body? When, and where, was human culture born?
"It's the hot issue, and we all have different positions," said Dr. John E. Yellen, an archaeologist with the National Science Foundation.
For much of the last century, archaeologists thought that modern behavior flowered relatively recently, 40,000 years ago, and only after Homo sapiens had pushed into Europe. They based their theory of a "creative explosion" on evidence like the magnificent cave paintings in Lascaux and Chauvet.
But some rebellious researchers suspected that this theory was a relic of a time when their discipline was ruled by Eurocentrism. Archaeologists, the rebels contended, were simply not looking for earlier creativity in the right places.
Several recent discoveries in Africa and the Middle East are providing the first physical evidence to support an older, more gradual evolution of modern behavior, one not centered in Europe. But other scientists, beyond acknowledging a few early sparks in Africa, remain unswayed. One prominent researcher is putting forward a new hypothesis of genetic change to explain a more recent and abrupt appearance of creativity.
The debate has never been so intense over what archaeologists see as the dawn of human culture.
"Europe is a little peninsula that happens to have a large amount of spectacular archaeology," said Dr. Clive Gamble, director of the Center for the Archaeology of Human Origins at the University of Southampton in England. "But the European grip of having all the evidence is beginning to slip. We're finding wonderful new evidence in Africa and other places. And in the last two or three years, this has changed and widened the debate over modern human behavior."
The uncertainty and confusion over the origin of modern cultural behavior stem from what appears to be a great time lag between the point when the species first looked modern and when it acted modern. Perhaps the first modern Homo sapiens emerged with a capacity for modern creativity, but it remained latent until needed for survival.
"The earliest Homo sapiens probably had the cognitive capability to invent Sputnik," said Dr. Sally McBrearty, an anthropologist at the University of Connecticut. "But they didn't yet have the history of invention or a need for those things."
Perhaps the need arose gradually in response to stresses of new social conditions, environmental change or competition from nonmodern human species. Or perhaps the capacity for modern behavior came late, a result of some as yet undetected genetic transformation.
Dr. Mary C. Stiner, an archaeologist at the University of Arizona, said those contrasting views, or variations of them, could be reduced to this single question: "Was there some fundamental shift in brain wiring or some change in conditions of life?"
Sudden Genetic Advance
The foremost proponent of the traditional theory that human creativity appeared suddenly and mainly in Europe is Dr. Richard G. Klein, a Stanford archaeologist. He describes his reasoning in a new book, "The Dawn of Creativity," written with Blake Edgar and being published next month by John Wiley.
"Arguably, the `dawn' was the most significant prehistoric event that archaeologists will ever detect," the authors write. "Before it, human anatomical and behavioral change proceeded very slowly, more or less hand in hand. Afterward, the human form remained remarkably stable, while behavioral change accelerated dramatically. In the space of less than 40,000 years, ever more closely packed cultural `revolutions' have taken humanity from the status of a relatively rare large mammal to something more like a geologic force."
In that view, 40,000 years ago was the turning point in human creativity, when modern Homo sapiens arrived in Europe and left the first unambiguous artifacts of abstract and symbolic thought. They were making more advanced tools, burying their dead with ceremony and expressing a new kind of self-awareness with beads and pendants for body ornamentation and in finely wrought figurines of the female form. As time passed, they projected on cave walls something of their lives and minds in splendid paintings of deer, horses and wild bulls.
As an explanation for this apparently abrupt flowering of creativity, Dr. Klein has proposed a neurological hypothesis. About 50,000 years ago, he contends, a chance genetic mutation in effect rewired the brain in some critical way, possibly allowing for a significant advance in speech. The origin of human speech is another of evolution's mysteries. Improved communications at this time, in his view, could have enabled people "to conceive and model complex natural and social circumstances" and thus give them "the fully modern ability to invent and manipulate culture."
Although this transformation, with the genetic change leading to the behavioral change, occurred in Africa, Dr. Klein writes, it allowed "human populations to colonize new and challenging environments."
< sarcasm>Yeah right. < /sarcasm> I put sarcasm in front to show something that you still don't understand. A mistake is an error is lexcorp. Your effete protestations notwithstanding, your moral etc. "superiority" is not. The "Great Green" whatever is your invention not mine. So you lie again...
This from a guy suggesting that we need to include the Great Green Arkleseizure in any discussion of the origin of species?
You are continually displaying your irrationality. You even go as far as try to impress by mentioning what you do for a living. Who cares what you do when your communication and thinking skills are at the level of a rabid shrew. As I mentioned before, God help us if you are still involved in designing our defensive systems.
It is plain to see that you are the one doing the slalom. The time has been reached where humor in watching you make a fool of yourself has been been superceded by the expenditure of time. Goodbye. Cackle to the world and try convince the yokels therein of your intellectual superiority, you've no chance here unless you try it in a mirror.
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American Association for the Advancement of Science, Early humans dressed for dinnerSophisticated jewellery appeared with social events.18 February 2002
Our early ancestors glammed-up for a get-together. Humans worldwide began wearing jewellery at the same time as groups started meeting up, say US researchers. The finding counters the idea that 'modern' behaviour swept the globe when modern humans migrated out of Africa. Residents of Kenya around 40,000 years ago wore beads and pendants made from ostrich eggshell; those in Turkey and Lebanon preferred seashell chic. The ancient beads and necklaces were unearthed by Mary Stiner and her colleagues in Turkey1 and by other teams at sites in Lebanon, Africa and Europe. Such ornaments are seen as a sign of sophisticated behaviour. "We think it typifies modern humans," says Stiner, of the University of Arizona in Tucson. Like today's wedding rings and medallions, jewellery says a lot about availability, wealth and religion. "These trinkets really do matter," she says. Adornments appeared when growing populations made groups more likely to encounter each other, she told the meeting of the American Association for the Advancement of Science in Boston. Suffering artists Animal remains around the Mediterranean suggest that human diet changed 40,000-50,000 years ago. People switched from easy-to-catch shellfish and tortoises to fast-moving birds and rabbits, the team also found. Rising population density probably made food scarce. The expansion of glaciers, forcing people south, could have worsened the crush. These findings suggest that modern human behaviour appeared simultaneously on different continents. This counters the theory that sophisticated behaviour emerged when anatomically modern humans spread out of Africa around 40,000-50,000 years ago, replacing culturally primitive Neanderthals. "There are many signs of modernity before then," agrees archaeologist Lawrence Straus of the University of New Mexico, Albuquerque. Cultured behaviour was an adaptation to changing conditions, he argues. Other archaeological evidence - such as sophisticated tools and art -appear in the fossil record before anatomically modern humans. |
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I pray for some useful result every time I do an experiment.
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