WHO WERE THE MOROCCO HUMANS? – PLoS Blogs (blog)


OLDEST HOMO SAPIENS?

It’s a little startling that so many of the media reports of the very old human fossils from Jebel Irhoud in Morocco accepted without question that these people were members of our own species, Homo sapiens.

“The remains of five early Homo sapiens have been unearthed at a site in northwest Africa,” said George Dvorsky at Gizmodo.  “Homo sapiens were hanging around and hunting gazelle in North Africa 100,000 years earlier than was previously believed” said Ephrat Livni at Quartz.

And even at Sapiens, the very serious and respectable anthropology site, Nicola Jones said, “The oldest bones yet of our species have been found.” Dating the fossils was complicated, but they turned out to be about 315,000 years old, give or take. If they are H. sap, Jones would be right; they would be the oldest so far found. Nobody seems to be disputing the dating, just the classification.

Likewise, at Discover’s Dead Things, Gemma Tarlach wrote that the researchers “unearthed multiple individuals forming the earliest known population of Homo sapiens, 100,000 years older and more than 3,000 miles from the site” in Ethiopia where Richard Leakey found Omo I and Omo II, two H. sap skulls dated at just under 200,000 years ago.

And they’ve got experts on their side. First there are the researchers themselves, headed by Jean-Jacques Hublin of the Max Planck Institute for Evolutionary Anthropology in Leipzig, a pinnacle of human paleontology. He says the find represents “the very root of our species, the oldest H. sapiens ever found in Africa or elsewhere.”

Other experts concur. The prominent paleoanthropologist Chris Stringer co-wrote with Julia Galway-Witham the News & Views commentary that accompanied the Nature papers (one on the find generally and the other on dating and tools). They accept the H. sapiens designation unreservedly.

WHO WERE THE MOROCCO HUMANS?

So, are these five fossil folks members of Homo sapiens? DNA could settle the question, But no DNA has been recovered, although the researchers have tried. The fossils are associated with tools said to be Middle Stone Age. Their faces are rather like ours.

But their head shape is not, and because of that their brains probably were organized differently from ours. There were other differences in brain anatomy. The cerebellum was smaller (although not as small as Neandertals.) In short: they are Homo, which is to say human, yes. But Homo sapiens? Some experts beg to differ.

Some comments were snarky, if entertaining. An anonymous evolutionary biologist told Annalee Newitz at Ars Technica that calling any ancient human fossil in Africa “the earliest whatever” is “clickbait.” Evolutionary biologist Curtis Marean told her more tactfully that the findings are “very important to know, but perhaps not unexpected.” Geneticist Rebecca Cann, the mother of “Mitochondrial Eve,” agreed. She told Newitz that the Moroccan finds were transitional forms, only to be expected. A “nothingburger.”

Perhaps not surprisingly, the more cautious accounts tend to come from old journalistic hands, and several quote the prominent paleoanthropologist John Hawks as chief skeptic. He pointed out to Kate Wong at Scientific American that the new finds’s H. sap-like faces were similar to those on the much older (800,000 years ago) Spanish fossils called H. antecesssor.

Present-day people, the last Homo standing, are known as anatomically modern humans. Hublin and his colleagues believe the Moroccan fossils represent early anatomically modern humans. “These papers are going a step too far, I think,” Hawks told Michael Greshko at National Geographic. “They redefine the concept of Homo sapiens by creating this category of ‘early modern humans’ that I’ve never seen before.”

This is a composite computer reconstruction of a Homo fossil skull from Jebel Irhoud in Morocco. It shows a modern flattened face like today’s humans, but the elongated braincase is an archaic feature. Credit: Philipp Gunz, MPI EVA Leipzig

María Martínon-Torres pointed out to Ewen Callaway at Nature News that the fossils lack prominent chins and foreheads, usually regarded as defining H. sap features. The Smithsonian’s Rick Potts suggested to NPR’s Christopher Joyce that the fossils could be a snapshot from just before we evolved.

That’s the central question here: what features define our species? Paleoanthropologist Marta Lahr pointed out to Wong that if the salient anatomy is our small faces and distinctive lower jaw shape, then the Moroccan finds could be our direct ancestors. But if we’re defined by cranium shape and the way our brains are organized, then they are our cousins.

One thing the fossils do make clear is that the Homo genus was evolving like mad over much of Africa several hundred thousand years ago. Ethiopia, of course, has long been thought to be the original home of Homo sap. But there have been other (probable) H. sap finds in Tanzania, Zambia, South Africa as well. All of these are sub-Saharan sites.

The Moroccan fossils would, if they are indeed Homo sap, be the first found in North Africa. A nice map accompanying Ann Gibbons’s post at Science shows that Homo sap evolution appears to be pan-African. Kate Wong observes at SciAm, “far from tidily solving the puzzle of our origins, the Jebel Irhoud discoveries add to mounting evidence that the dawning of our kind was a very complicated affair.”

OBAMACARE VS. TRUMPCARE: THE END APPROACHES?

It’s not looking good for hanging on the Affordable Care Act, aka Obamacare. The health care stuff going on in Congress about repealing and replacing the ACA has gotten so vile that two veteran health care journalists have just posted high-profile rants about it.

Let’s start with Julie Rovner, who has written about health care policy since 1986 and now is at Kaiser Health News.  At STAT, she slams “the Senate GOP leadership’s top-secret process to try to write a health bill that could change the formula for nearly one-fifth of the nation’s economy, with a vote they want to cast by July 4.”

It is said that no drafts of the Senate bill will be available until it’s finished, but Dylan Scott has the latest guesses about what it might contain at Vox. I imagine this is a moving target, as Republican Senators make minor changes in order to sweeten the medicine for reluctant colleagues. One easy way to keep up: STAT has published a list of Twitter feeds to follow.

“The extreme secrecy is a situation without precedent,” Rovner says. But she also regards the current Congressional opacity as the culmination of an anti-transparency process that has been under way in Congress for a long time–and endorsed by both parties.

Sarah Kliff has been covering health care politics and policy since 2009. In addition to the Senate writing a health care bill in secret, she says at Vox, the administration is also simply lying about what provisions it will contain.

Administration officials say no one will lose Medicaid. But two independent analyses of the bill the House passed (the American Health Care Act, whose features are rumored to be part of the ghostly Senate bill) have reported that millions of people will lose Medicaid coverage. They say people with pre-existing conditions will be protected; they won’t be. They say deductibles will go down, but they’ll go up. Etc.

Yes, this strategy may well catch up with Republicans and bring them to disaster in the Congressional elections next year. “But that will only happen after people suffer the consequences of a rushed bill considered quickly with little public debate,” Kliff says.

“This is the most damaging part of the lack of public discourse around the Republican repeal efforts: There are millions of real lives at stake that could be hurt. These people would suffer the consequences that will happen much faster and matter much more than any election.”


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