from the September 20, 2011 eNews issue
http://www.khouse.org (visit our website for a FREE subscription)
There were once a much wider variety of human beings on this planet than there
are now, according to new genetic analyses of Neanderthals in Europe and
Denisovans in East Asia. Modern humans once interbred with these other groups,
apparently sharing genetic material that includes the ability to fight off
certain diseases. Yet, not all creatures designated as "hominids" are
related to humans.
In 2008, a piece of bone and a tooth of what is believed to be a young girl
were found in Denisova Cave in southern Siberia, along with stone blades and
body ornaments. Twenty years ago the small bone and a tooth would not have been
much to go on. These days, however, 40 mg of real bone from a fossil can tell
researchers a great deal of information - if the bone contains enough genetic
material for researchers to sequence the DNA.
Researchers were able to compare DNA all around, and it turns out that the
Denisovan girl and Neanderthals are related, but not directly. According to
comparisons of genetic code, the Denisovan shared a common ancestor with
Neanderthals and modern humans.
"It amazed me that we found this other extinct group of humans,"
evolutionary geneticist Svante Pääbo at the Max Planck Institute for
Evolutionary Anthropology at Leipzig, Germany, told LiveScience. "When we
got this little finger bone from Siberia, I was totally expecting it to be
either Neanderthal or modern human. When it was something else, that was
totally surprising and shocking to me."
Ancient humans might bear some superficial physical differences from modern
homo sapiens, but they were all still humans and able to breed with one
another. In fact, interbreeding between modern-form humans and Neanderthals may
have given us modern humans certain genes that helped boost our immune
systems.
At the least, Neanderthals share key immunity genes with us, namely the HLA
(human leucocyte antigen) class 1 gene. HLA proteins are important in helping
the body defend itself against new infections. A variant called HLA-B*73 is
found both in modern humans and Denisovans.
There's quite a bit of Neanderthal DNA floating around out there in the
population. According to researchers, up to four percent of Neanderthal DNA and
up to six percent of Denisovan DNA have survived in modern humans. It's been
known for some time now that Neanderthals bred with the people whose
descendants are now found in Europe and western Asia. Denisovan genes can also
be found in the population of Europe and especially in the people of Asia and
the oceanic islands.
No Missing Links
For more than a century, Neanderthals were portrayed as brutish, evolutionary
missing links. They brought to mind the knuckle-dragging cave man, little
better than apes themselves. Those pictures of Neanderthal are sadly incorrect.
Evidence consistently points to Neanderthals as an extinct, but completely
human, group of individuals. Neanderthals used tools, buried their dead, and
even made musical instruments. The Denisovan bones were found with tools and
body ornaments, which are both characteristic of human beings.
In the Bible, Adam's son Seth was born as a replacement for Abel, who was
murdered by Cain. However, Cain, Abel, and Seth were not the only children Adam
and Eve produced. Genesis 5:4 states that Adam lived another 800 years after
Seth was born, and he begat sons and daughters. Seth's importance in the story
comes from the fact that it is through his descendants that Noah is born. The
only human genetic lines that survived the Flood were those that climbed on
board the ark – namely, the genes of Noah's three sons and their wives.
With the Flood, God wiped out nearly all of humanity. He preserved one
slender group of genes to continue on through the children of Shem, Ham
and Japheth. It should therefore be no shock that we find the remains of other
extinct humans that don't look exactly like us. Their gene pools were nearly
wiped out.
Apes Are Still Apes:
On the other hand, paleoanthropologists are constantly seeking out new
fossils they hope will finally provide science with the missing links between
apes and humans. The newest human precursor is Australopithecus
sediba. A. sediba was discovered in South Africa in 2008 by a
little boy and his dog, and later identified as an australopithecine, a
cousin of the famous Australopithecus afarensis, Lucy.
While A. sediba provides an exciting new puzzle piece for evolutionary
paleoanthropologists, its similarities to humans - just like Neanderthal's
differences - are superficial. A. sediba has been lauded for having
hands strong enough to grasp tree branches while at the same time have hands
that could use tools. Its pelvis is also more curved than other
australopithecines, which the researchers believe would have made it easier for
females attempting to give birth to babies with larger heads and brains. The
fact that A. sediba itself has a small head, with a brain capacity of
only 420 cc, doesn't discourage the scientists. They consider A sediba
to be a possible human ancestor, and therefore the researchers see a human
head-friendly pelvis in A. sediba. Whether this is a
case of, "If I hadn't believed it, I wouldn't have seen it," requires
a second opinion.
"They are important fossils and remarkably detailed," said
paleontologist Bernard Wood of George Washington University in D.C.. Wood
stood among those paleontologists who were not yet willing to support
A. sediba as a human ancestor. "I have some resemblances to Warren
Buffett, but I'm not a billionaire," Wood says. "A few resemblances
does not an ancestor make."
At the end of the day, A sediba is still an ape. She is an ape
with long fingers and a wide pelvis. No tools or jewelry were found with A
sediba. The apes did not bury their dead nor play handmade flutes. A.
sediba simply represents the longing of paleoanthropologists to fill in
the gaps between humans and apes on an evolutionary tree.
The difficulty is that the gaps are fairly large. Each new fossil discovery
adds just one more individual to either the human family branches or the
ape family branches. As much as paleoanthropologists want the two sets of
branches to eventually run into each other, as time progresses, they look
more and more like two, many-branched bushes and not one single tree at all.
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PEOPLES IS PEOPLES... AND APES IS APES