Humans Strange, Neanderthals Normal

[GrandMasterTerwynn]

According to researchers.

Scientist: Humans Strange, Neanderthals Normal
By Charles Q. Choi
Special to LiveScience
posted: 08 September 2006
12:05 pm ET


Neanderthals are often thought of as the stray branch in the human family tree, but research now suggests the modern human is likely the odd man out.

"What people tend to do is draw a line from our ancestors straight to ourselves, and any group that doesn't seem to fit on that line is divergent, distinct, unusual, strange," researcher Erik Trinkaus, an anthropologist at Washington University in St. Louis, told LiveScience today. "But in terms of evolution of our family tree, the genus Homo, we're the outliers and the Neanderthals are more toward the core."

Humans are not at the inevitable end of a sequence, Trinkaus said. "It just happens that we happen to be alive today and Neanderthals are not."
Humans & Neanderthals

How They Were Similar

Trinkaus spent decades examining fossil skeletons and over time realized that maybe researchers looked at Neanderthals the wrong way. Over the last two years, he systematically combed through fossils, comparing Neanderthal and modern human skull, jaw, tooth, arm, leg traits with those of the earliest members of the genus Homo in terms of their shape.

"I wanted to see to what extent Neanderthals are derived, that is distinct, from the ancestral form. I also wanted to see the extent to which modern humans are derived relative to the ancestral form," Trinkaus said.

Trinkaus focused on skeletal features that seemed most strongly linked to genetics, as opposed to any traits that might get influenced by lifestyle, environment or wear and tear.

When compared with our common ancestors, Trinkaus discovered modern humans have roughly twice as many uniquely distinct traits as Neanderthals. In other words, Neanderthals are more like the other members of our family tree than modern humans are.

"In the broader sweep of human evolution, the more unusual group is not Neanderthals, whom we tend to look at as strange, weird and unusual, but it's us, modern humans," Trinkaus said.

Modern humans, for example, are the only members of our family tree who lack brow ridges, Trinkaus said. "We are the only ones who have seriously shortened faces. We are the only ones with very reduced internal nasal cavities. We also have a number of detailed features of the limb skeleton that are unique."

Trinkaus published his findings in the August 2006 issue of the journal Current Anthropology.

An interesting take on our relationship to the other members of our immediate family tree.

[Surlethe]

So we're the black sheep of the family, more so because we killed our cousins. Could the unique elements of our genes be part of the reason why we're still alive, and they're not?

[King Kong]

Could the unique elements of our genes be part of the reason why we're still alive, and they're not?

There must be something unique about us that gave us the edge over other hominid competitors. This major difference would have to be reflected in our genetic makeup somehow, rather than being a purely environmental cause. This is because even though humans inhabit nearly every land environment on Earth, they all have very similar genes and have the same mental capabilities. So the cause for our unique brains should be in our genes. Though I'd think that this genetic difference would probably not reflected in this survey of skeletal differences.

However, I have heard some say that the expansion of our frontal lobe allowed us to think in abstract terms (IIRC), thus giving us our major mental advantage. This could be reflected in our unique forehead (rather than brow ridges), which makes room for the enlargened frontal lobe.

[Havok]

Perhaps it's something that you can't find in fossil records. Perhaps Neandrathal mated with only one other in thier lives. And we, homosapien, spread the seed all over the place. Or perhaps the period of incubations was longer say 18 months instead of 9. Damn, we need time machines.

My thoughts have absolutely no basis in fact Just thoughts.

[Noble Ire]

So we're the black sheep of the family, more so because we killed our cousins. Could the unique elements of our genes be part of the reason why we're still alive, and they're not?

I was under the impression that homo sapiens were simply able to better adapt to the changing environment at the end of the last ice age, and outproduced their evolutionary cousins into extinction. I recall something on the subject, National Geographic, I think, that mentioned that Neanderthal body structure was suited for close-quarters, forest hunting, and when their habitat began to give way to open grassland, they simply couldn't take in enough game to remain viable.

[Winston Blake]

See! See! Humans are special! Obviously this is because we were made by God the Lawd (and/or Aliens). Obviously humans are the odd ones out - we've got souls. Duh. It just took this long for the scientists and their dirty fossils to figure out what the Bible/Hubbard's been saying all along.

[Spyder]

There's not really any one specific sequence. There could have been ten different subspecies around and you wouldn't have picked one to be the main one and labled the rest as offshoots.

[GrandMasterTerwynn]

So we're the black sheep of the family, more so because we killed our cousins. Could the unique elements of our genes be part of the reason why we're still alive, and they're not?

Well, the genes controlling our neurological development have shown more changes over time than the equivalent genes in our living relatives. However, that isn't the whole story. For most of the history of the history of the Homo genus, technological development seemed to take place at a very slow pace. The sophistication of tools slowly increased from those produced by Homo Habilis and his contemporaries, through Erectus and his contemporaries, and through Neanderthal and Sapiens. As a matter of fact, for most of the time Homo Sapiens has lived on Earth, the toolkits posessed by most of our populations weren't much improved over the kits Neanderthals used.

The exceptions to this rule were a few coastal communities, and other locales where the natives had access to high-quality protein to fuel their brains and permitted them to better exercise the parts of their brain capable of abstract thought (these populations produced artifacts highly suggestive of decorative/symbolic bead necklaces/bracelets.) According to one theory, they would've remained the exceptions to the rule were it not for the eruption of a massive supervolcano called Toba. Around that time, human populations apparently diminished dramatically. Some estimates, based on our current lack of genetic diversity, suggest that every human on Earth is descended from only a few thousand individuals who managed to survive the catastrophe. (This may not be saying that everybody but these survivors were wiped out. It may just be that other populations were sufficiently stressed that the ones we call 'survivors' expanded and displaced the remnants of the other populations of Homo Sapiens.)

Regardless, these survivors originated from the same places that produced the first strong evidence for symbolic and abstract thought. This gave them an edge over their more literal-minded neighbors, such as other archaic Homo Sapiens, the variants of Homo Erectus running around in Asia, and the Neanderthals. (Though the Neanderthals might've had a similar ability to abstract and symbolize. There are sites suggestive of Neanderthals having buried their dead with grave goods and red pigment, and the tools they produced near the end of their time on the planet seem to show they were perfectly capable of adapting the significantly more sophisticated Sapiens toolmaking techniques for their own uses.)

Broadly speaking, the answer to your question is "yes." Principally because Neanderthals seem to have overspecialized into big-game hunters. They died out at about the same time their favored prey did, unlike modern humans with their more diverse diet.