Posted on 12/25/2004 4:48:07 PM PST by PatrickHenry
It is one of the best-known stories in science: the evolution of mankind from ape-like creatures to modern humans via knuckle-grazing cave-dwellers. Now it has been blown apart by the first comprehensive study of all the fossils, which has revealed that they are probably all variants of Homo sapiens.
The discovery comes as fossil-hunters in Indonesia continue to defend claims to have found yet another new species of human, dubbed "Hobbit Man". If true, the diminutive creature would join such famous specimens as Lucy, Java Man and the Neanderthals in the complex family tree of mankind.
The findings have significant implications for the often bitter debates between fossil-hunters about the significance of their finds. While they no longer bicker over the so-called "Missing Link" - the now-derided idea of a creature linking humans to chimpanzees - experts continue to argue over the relationship between Australopithecines and early humans, and between Neanderthals and modern humans.
The number of human species claimed by fossil-hunters now stands at around 10, while the total number of human-like species exceeds 50. Such claims have long been based on supposedly significant differences in sizes and shapes of fossil bones. Now they have all been thrown into doubt by research showing that the differences lie within the range expected for just a single species.
Professor Maciej Henneberg, of the University of Adelaide, a world authority on fossil human anatomy, made the discovery after analysing the skull sizes and estimated body weights for all of the 200 identified specimens of human-like fossils known as hominims. These span the entire history of humans, from the emergence of so-called Australopithecines with an upright stance more than four million years ago to neolithic modern humans from around 10,000 years ago.
Prof Henneberg found that the fossils show clear evidence of evolution, with substantial increases in both skull sizes and body-weight. However, he also found that the fossils show no evidence of being anything other than a single species which had grown bigger and smarter over time. According to Prof Henneberg, the much-vaunted differences in fossil size used to identify "new" species all lie within the normal range expected for one species.
Plotted out as a graph, they form the classic bell-shaped curve found using data from modern humans.
Reporting his findings in the current issue of the Journal of Comparative Human Biology, Prof Henneberg concludes: "All hominims appear to be a single gradually evolving lineage containing only one species at each point in time."
The findings have big implications for the often bitter debates between fossil-hunters about the significance of their finds. Experts have long bickered over the relationship between Australopithecines and early humans, and between Neanderthals and modern humans.
Prof Henneberg has said that the new results suggest such disputes are meaningless, as they ignore the possibility of huge differences within the same species.
He said they also raise doubts about the reliability of bones in identifying new human species: "There is no precise way in which we can test whether Julius Caesar and Princess Diana were members of the same species of Homo sapiens".
According to Prof Henneberg, the study highlights the scant evidence for so many of the claimed new species of human. "Considering that there are only about 200 specimens in total, if these really do represent ten different species, that makes an average of just 20 specimens per species". He added that only a single skull had been found for the "Hobbit Man" of Indonesia.
Other authorities hailed Prof Henneberg's findings as a much-needed reality check. "Clearly there is a need to be more aware of the possibility of variation - but that is not the inclination today," said Geoffrey Harrison, emeritus professor of biological anthropology at the University of Oxford. "It has been a problem because the discoverers have usually put so much effort into finding the evidence, so they want it to be important".
Professor Chris Stringer, a leading expert on human fossils at the Natural History Museum, London, said even Neanderthals were not significantly different in skull or body size from modern humans. However, he added that they do differ in other details, such as inner ear bones.
He said: "The argument they are a different species is, of course, only a hypothesis, but comparisons of skull shape published recently certainly show they are as different from us as monkeys and apes are different from each other".
According to Prof Henneberg, there are fewer than 30 examples of Neanderthals on which to base any conclusions. What evidence there is, however, is consistent with Neanderthals being from the same species as modern humans.
He added that the never-ending announcements of new species said more about those making the claims than about human evolution. "The problem is there are far more palaeontologists than fossil specimens".
This is a Christmas crevo thread. No "humbug!" jokes. Everyone be nice.
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Thanks for bringing this article to my attention.
I thought "being nice" was guaranteed by point 5 on your "agreement of the willing" on your About Page. ;-)
As it is, I wonder what classifications about species we'd make about the many variants of good old Rover & his friends, if we didn't know about dog shows.
It might make for a good sci-fi short story of the type Isaac Asimov used to write...
You never sleep..do you....Merry Christmas.
Christmas greetings from PatrickHenry: Christmas 1776.
Do we really need another study in anthropology? Heck, there's still ape-like humanoid creatures and knuckle-grazing cave-dwellers wandering the streets today.
I'm pretty sure that if you graphed, say, the body masses of a few thousand critters chosen at random you'd get a bell curve, too. Not too good an argument for their all being the same species.
MORE - see link above.The proper study of mankind
Jun 29th 2000
From The Economist print editionPractical applications are all well and good. But genomics can shed light on the nature of humanity, too
UNTIL the late 1980s, the most useful tools that could be deployed by people who were interested in human origins were the trowel and the cleaning brush. Fossil-hunters had done wonders uncovering specimens of early humanity that told a story of an African genesis, followed by the spread to Eurasia of a species called Homo erectus. But the emergence of modern man, Homo sapiens, was a mystery. Some researchers argued that modern people evolved in one place and then, like Homoerectus, spread out, though they did not agree about where and when this happened. Others believed that the whole erectus population gradually and simultaneously evolved into sapiens.
That argument was settled by genetics. The late Allan Wilson, a researcher at the University of California at Berkeley, managed to show the truth about human evolution without picking up a single trowel. He studied the pattern of DNA in people now alive, and produced a human family tree showing that the species emerged in Africa about 200,000 years ago and first left the continent to begin its worldwide spread 100,000 years ago.
ping
Plotted out as a graph, [fossil dimensions] form the classic bell-shaped curve found using data from modern humans.
I'm pretty sure that if you graphed, say, the body masses of a few thousand critters chosen at random you'd get a bell curve, too. Not too good an argument for their all being the same species.
YEC SPOTREP
The problem is that such a "weights and heights" measure is an extremely simplistic measure. Just because there are modern humans who are midgets, that doesn't mean that an Australopithecus would be taken for a "normal" modern human if one were to be brought to the present using a time machine. You'd still freak out if you saw one walk into the 7-11.
I don't know *any* modern humans who look even remotely like *this*:
Massive brow ridge, *NO* forehead, a braincase you could wrap your hand around like a football, a prominent protruding muzzle, small close-set eyes, jawbone larger than the braincase, etc. etc. Compare to the proportions and angles of a modern human skull:
I'd have to see that. My feeling is that a sufficiently large sample of all critters would approach a normal distribution. Samples from particular species would be buffered by samples from other species with similar, but not identical, attributes and the modes would be smoothed away.
But I could easily be wrong; statistics is not my best subject (!).
Trying to say something about John Kerry, Jesse Jackson, and Ted Kennedy, are you?
I doubt very much that human ancestors consumed knuckles to the exclusion of other body parts. It unlikely that they were even the preferred food.
read later
Sorry, man - was it that obvious? Okay, to right my wrongs, throw in Cantwell, Pelosi, Maxine, and our new governor Chris "I-used-to-be-called-Christine-until-I-ran-for-governor" Gregoire.
Does that make up for my wrongs? :)
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