Jeg er blevet gjort opmærksom på følgende link:
http://www.telegraph.co.uk/news/main.jhtml?xml=/news/2004/12/26/wspecies
26.xml&sSheet=/news/2004/12/26/ixworld.html
i sci.archaelogy. En professor Maciej Henneberg skal have fundet ud af
at godt kan glemme alt om eksistensen af mere end én menneskeart,
herunder de uddøde australopithecinere. Han mener ganske simpelt at der
lige fra de først fundne homininer til dagens George Bush Jr kun har
været tale om én art, der gradvist har udviklet sig.
===
Believe it or not, they're all the same species
By Robert Matthews, Science Correspondent
(Filed: 26/12/2004)
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.
Click to enlarge
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".
28 October 2004: Scientists find new species of 3ft humans
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