From Newsgroup: sci.anthropology.paleo
On 9/29/25 21:53, David Dalton wrote:
Here is a post by Julian on alt.buddha.short.fat.guy
of a text by Mike Pitts.
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A new report from the field of human origins had sub-editors reaching
for their hyperboles. A million-year-old skull, we have learnt, has rewritten humanityrCOs story. The finality of this is misleading, but
there is nonetheless something going on here.
For decades, Chinese archaeologists have been investigating a site known
as Yunxian, beside a tributary of the Yangtze river. The researchers
have been rewarded with human fossils rCo to date, three skulls around a million years old. These bones have been preserved well but the skulls
have been crushed. As a result, comparing them with other fossils, and therefore finding exactly which species they might represent, has been a challenge.
The skulls are broken, but not distorted: most of the right bits are in
the right shape, just not in the right places. In a new study, published
in the journal Science, a dozen Chinese archaeologists and scientists
joined by Chris Stringer of LondonrCOs Natural History Museum, claim to
have overcome this difficulty using cutting edge digital imaging and computer modelling to put them back together again. After doing so, they have revealed that a nearly complete skull found in 1990 is something no
one had predicted: a creature that suggests our own family tree, made up
of Homo Sapiens, is twice as old as previously thought. WhatrCOs more,
this early ancestor of ours was walking around Asia, but apparently not Africa. How did we get here? And what does it tell us about ourselves?
It has long been agreed that humanityrCOs deep origins lie in Africa. A major genetic study released earlier this year found that humans and our chimpanzee ancestors separated from each other a little over five or six million years ago. What happened next on our side has become complex, if
not downright confusing. The number of apparent species, and which parts
of Africa, Europe or Asia they occupied and when, has come under
constant scrutiny.
The first close human lookalike appeared in Africa around two million
years ago in the form of Homo erectus. Humans soon spread into rCo or appeared as related species in rCo parts of Europe and much of Asia.
Making sense of the rare and fragmentary fossil evidence has been helped
by genetic studies, which have confirmed the later and simultaneous
presence of three species across Eurasia by around half a million years
ago: Neanderthals rCo Homo neanderthalensis rCo in the west, Denisovans in the east, and the more widespread Homo sapiens occasionally breeding
with the others. Ancient DNA and proteins recently identified a Chinese skull known as Dragon man as the first known Denisovan face, and
Denisovans have been described, somewhat controversially, as a species
known as Homo longi.
The new study extends this picture with further complexities and a
longer history. The Yunxian skull, say the scientists, has a mix of
ancient and newly acquired features. Parts recall erectus fossils, while
its brain is larger, and the craniumrCOs face and lower back instead
compare favourably to Dragon man rCo or even, says Stringer, Homo sapiens. The skullrCOs age, however, independently shown by geology and the particular ecosystem of mammals in the siterCOs well-preserved remains, suggests it comes from the erectus era.
The team resolves these apparent contradictions by rethinking the
historic human landscape. In this new view, ancestral Neanderthals, Denisovans and sapiens separated a little over a million years ago,
rather than around 500,000 years ago.The theory posits that
Neanderthals, Denisovans and sapiens were alive at the same time as Homo heidelbergensis (traditionally thought of as the common ancestor of Neanderthals and sapiens) and later Asian Homo erectus. In other words,
for hundreds of thousands of years our planet hosted five highly intelligent, large-brained types of human. In the long run, only one survived: us.
What does this mean for other human fossils we have found? Homo
antecessor, for example, a species identified from remains in a Spanish
cave at Atapuerca, has been proposed as an ancestor to heidelbergensis;
this would put it at the root of the group that includes us and Neanderthals. That has always been controversial (itrCOs the excavatorsrCO idea), and in the new analysis, the antecessor species is said to belong
to the Denisovan group rCo and so, ultimately, doomed to extinction.
Genetic studies have suggested different relationships, separating
Dragon man from its African ancestors a relatively recent 700,000
years ago.
And then there are the fossils we donrCOt have. If Neanderthals,
Denisovans and sapiens evolved away from each other a million years ago, there must have been earlier human forms not yet seen. The placing of
their common ancestor among the intertwined branches of early human
trees is unknown. It all opens up a quest for previously unsuspected
types of fossils.
ItrCOs the bigger picture here which is particularly exciting. Only archaeology can help us understand the nature of all these creatures:
how they behaved and thought. Thirty years ago, archaeologists talked of
a revolution marked by the sudden appearance of sophisticated art in
Europe rCo indication, it was said, of the arrival of the modern human
mind a mere 30 or 40,000 years ago. Evidence from the ground has since
shown such developments also occurred far beyond Europe, and over a
longer time span.
If early Homo sapiens evolved a million years ago, as this study
suggets, when did individuals start to make art? At what point did they become rCymodernrCO rCo and why? Could this have happened first in Asia, rather than Europe or Africa, and again, if so, why? Sooner or later
werCOll get to answer such questions. Doing so will take us into a new, deeper understanding of who we really are.
Mike Pitts
Where does one species end and another one begin? Where
does one genus end and another one begin?
Even though humans may not have regularly circumnavigated
the Earth over a million years ago, perhaps there may have
still been some movement and interbreeding between adjacent
populations enough that humans were still essentially one
species all the way from something like chimpanzee to human?
I guess overall, this sorting of fossils in bins now has
progressed to the genus 'Homo', but can even college professors
be biased upon whether they or someone might 'think' ('sapiens')
is validly applied?
Man progressed from an average brain size of one quarter that
an average modern human (chimpanzee) to the current average based upon inference from the fossil record, but among the human population in the present there is some variation generally associated with the size of
the human. That can range as great as one half the average to twice the average. There is also something proposed to be significant - brain
mass to body mass ratio. But each one of those neurons is an
operational amplifier. Why would not more of them add to more computing
power in a brain (at least when it comes to grey matter and not white
matter)? (The average brain size of elephants is about twice that of an average human, and the cetaceans range from the smallest .75 human
average to the largest whales or 4 times human average but the other
side of the equation is that the horse on average has about twice the
brain mass of an average chimpanzee and one half that of an average
human, along with lions, some bears, hippos, rhinos, and some others.
The cow has an average brain mass equal to that of an average
chimpanzee, but some humans eat cows.)
Perhaps the best solution is to drop the genus Homo entirely? That
way humans might have less of a penchant for calling an organism
'not human'? Then if there is still a problem they could drop similar
sounding names like hominoidea, hylobatidae, or hominidae if there is a
problem even with that? Is anytime someone writes something, the past
writings are deleted? If everyone has a low attention span approaching
zero time, then it may be impossible to not rewrite history every time
anything is written.
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