January 3, 2013 | David F. Coppedge

What's Up with Alley Oop?

Here are some recent stories about human evolution.  Some might deserve to be in the comics.

1.  Lucy walked up right into the trees:  Nathaniel Dominy thinks Lucy’s ankle bones don’t rule out the possibility she was a tree-climber.  By studying the Twa tribe in Uganda, whose members routinely climb trees looking for honey, Dominy and colleagues found the fossil evidence of Australopithecus afarensis ambiguous.  That’s because the muscle and tendon changes associated with habitual tree climbing don’t fossilize.  PhysOrg posted a video clip explaining the problem.  Dominy’s work was published in an open-access paper in PNAS, where the abstract states,

Paleoanthropologists have long argued—often contentiously—about the climbing abilities of early hominins and whether a foot adapted to terrestrial bipedalism constrained regular access to trees. However, some modern humans climb tall trees routinely in pursuit of honey, fruit, and game, often without the aid of tools or support systems… Here we show that Twa hunter–gatherers use extraordinary ankle dorsiflexion (>45°) during climbing, similar to the degree observed in wild chimpanzees…. [O]ur results imply that derived aspects of the hominin ankle associated with bipedalism remain compatible with vertical climbing and arboreal resource acquisition. Our findings challenge the persistent arboreal–terrestrial dichotomy that has informed behavioral reconstructions of fossil hominins and highlight the value of using modern humans as models for inferring the limits of hominin arboreality.

Not so fast,” PhysOrg put it.  Claiming that Lucy didn’t climb trees “may be a rush to judgment in light of new evidence” in the paper.

2.  Clothes make the Peking Man:  The Homo erectus specimens collectively dubbed Peking Man apparently exhibited another human trait: they were fastidious about fashion.  Reporter Owen Jarus said in Live Science,

“Peking Man,” a human ancestor who lived in China between roughly 200,000 and 750,000 years ago, was a wood-working, fire-using, spear-hafting hominid who, mysteriously, liked to drill holes into objects for unknown reasons.

And, yes, these hominids, a form of Homo erectus, appear to have been quite meticulous about their clothing, using stone tools to soften and depress animal hides.

Jarus pointed out that these people made spears like Heidelberg Man, but they’re not sure if they learned the skill independently or at the same time.  As for the drilling of holes, just because living humans can’t figure out why they did it doesn’t mean the cave dwellers didn’t have good reasons.  They apparently made tools for their fashion industry.  “‘If they are depressing the hides, if they are softening hides, they can use the hides for their clothes,'” something no sophisticated hominids would dare live without.”  Alley Oop wore clothes, we remember from the cartoons, but since the hides didn’t fossilize with the skulls, we can’t really know how chic Mrs. Oop looked.

3.  Climate makes the man:  If you can believe a headline on PhysOrg, we are what we are because the weather was what it was.  “Fluctuating environment may have driven human evolution,” it reads; “A series of rapid environmental changes in East Africa roughly 2 million years ago may be responsible for driving human evolution, according to researchers at Penn State and Rutgers University.”  How did they come up with this notion?  By looking at leaves in an ancient lake.  Presuming the dates of those leaves tell a climate story, and presuming they match epochal periods of human evolution, they placed cause with effect.  But if anthropogenic climate change is a big modern debate, perhaps the hominids caused the climate change, not the other way around.

It seems this idea could be testable.  See if people in the polar regions are regrowing fur.  Without asking questions like this, the researchers convinced themselves that they had found natural “forcing mechanisms” to drive hominid evolution toward scholarship.  They didn’t explain why other species didn’t simultaneously learn abstract language and philosophy.

4.  Out of “Out of Africa” theories:  A new find musses up common ideas about humans emerging out of Africa.  Pamela Willoughby has found evidence of continuous habitation at two sites in Tanzania between 200,000 years ago and the present.  According to PhysOrg, this “may lead to a rethinking of how, when and from where our ancestors left Africa.” Many paleoanthropologists believe a genetic bottleneck after the Ice Age shows there was a migration into Europe at around 50,000 to 60,000 years ago, but Willoughby’s evidence includes the whole period before and after the bottleneck – all the way to the present.  She explained why this represents an upset:

“It was only about 20 years ago that people recognized that modern Homo sapiens actually had an African ancestry, and everyone was focused on looking at early Homo sapiens in Europe who appeared around 40,000 years ago,” she said. “But we now know that as far as back as around 200,000 years ago, Africa was inhabited by people who were already physically exactly like us today or really close to being the same as us. All of a sudden, it’s not Europe in this time period that’s really important, it’s Africa.”

What were hominids identical to us doing for 200,000 years against the inexorable forces of evolution?  Didn’t they read the bumper stickers, “Evolve or perish?”  Willoughby’s upset is just the latest upset until the next upset.

5.  Annus horribilis, a new endangered species:  Latin speakers will know that Annus horribilis means “terrible year,” not a Linnaean classification name.  But according to Science Magazine (Dec. 21), it was a terrible year for Homo sapiens var. anthropologist – a recent entry in the endangered species list.  A lot of anthropology graduates can’t find work.  There just aren’t that many jobs labeled “anthropologist,” so graduates are evolving into subspecies that adapt their image to a changing environment.  With multiculturalism a buzzword in certain quarters, anthropologists can advertise themselves as ones able to “research human life, history, and culture, and apply that knowledge to current issues” such as “diversity in the world”.  The article did not describe the plight of a minor subspecies of the clade, paleoanthropologists.

None of these stories really matter, because paleoanthropology is a field where every year or two they announce, “Everything you know is wrong.”  Since there are infinitely more wrong ideas than correct ones, changes to this pattern are unlikely when the blind lead the blind.  We offer paleoanthropology stories less as scientific discovery as much as funny pages.

 

 

 

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