Neandertais eram tão humanos quanto nós - por que os cientistas erraram feio com eles???

quinta-feira, janeiro 12, 2017

Neanderthals Were People, Too

New research shows they shared many behaviors that we long believed to be uniquely human. Why did science get them so wrong?


Neanderthal sculptures, named Nana and Flint, at the Gibraltar Museum. 

Credit Jaap Scheeren for The New York Times

Joachim Neander was a 17th-century Calvinist theologian who often hiked through a valley outside Düsseldorf, Germany, writing hymns. Neander understood everything around him as a manifestation of the Lord’s will and work. There was no room in his worldview for randomness, only purpose and praise. “See how God this rolling globe/swathes with beauty as a robe,” one of his verses goes. “Forests, fields, and living things/each its Master’s glory sings.” He wrote dozens of hymns like this — awe-struck and simple-minded. Then he caught tuberculosis and died at 30.

Almost two centuries later, in the summer of 1856, workers quarrying limestone in that valley dug up an unusual skull. It was elongated and almost chinless, and the fossilized bones found alongside it were extra thick and fit together oddly. This was three years before Darwin published “The Origin of Species.” The science of human origins was not a science; the assumption was that our ancestors had always looked like us, all the way back to Adam. (Even distinguishing fossils from ordinary rock was beyond the grasp of many scientists. One popular method involved licking them; if the material had animal matter in it, it stuck to your tongue.) And so, as anomalous as these German bones seemed, most scholars had no trouble finding satisfying explanations. A leading theory held that this was the skeleton of a lost, bowlegged Cossack with rickets. The peculiar bony ridge over the man’s eyes was a result of the poor Cossack’s perpetually furrowing his brow in pain — because of the rickets.

One British geologist, William King, suspected something more radical. Instead of being the remains of an atypical human, they might have belonged to a typical member of an alternate humanity. In 1864, he published a paper introducing it as such — an extinct human species, the first ever discovered. King named this species after the valley where it was found, which itself had been named for the ecstatic poet who once wandered it. He called it Homo neanderthalensis: Neanderthal Man.

Who was Neanderthal Man? King felt obligated to describe him. But with no established techniques for interpreting archaeological material like the skull, he fell back on racism and phrenology. He focused on the peculiarities of the Neanderthal’s skull, including the “enormously projecting brow.” No living humans had skeletal features remotely like these, but King was under the impression that the skulls of contemporary African and Australian aboriginals resembled the Neanderthals’ more than “ordinary” white-people skulls. So extrapolating from his low opinion of what he called these “savage” races, he explained that the Neanderthal’s skull alone was proof of its moral “darkness” and stupidity. “The thoughts and desires which once dwelt within it never soared beyond those of a brute,” he wrote. Other scientists piled on. So did the popular press. We knew almost nothing about Neanderthals, but already we assumed they were ogres and losers.

The genesis of this idea, the historian Paige Madison notes, largely comes down to flukes of “timing and luck.” While King was working, another British scientist, George Busk, had the same suspicions about the Neander skull. He had received a comparable one, too, from the tiny British territory of Gibraltar. The Gibraltar skull was dug up long before the Neander Valley specimen surfaced, but local hobbyists simply labeled it “human skull” and forgot about it for the next 16 years. Its brow ridge wasn’t as prominent as the Neander skull’s, and its features were less imposing; it was a woman’s skull, it turns out. Busk dashed off a quick report but stopped short of naming the new creature. He hoped to study additional fossils and learn more. Privately, he considered calling it Homo calpicus, or Gibraltar Man.

So, what if Busk — “a conscientious naturalist too cautious to make premature claims,” as Madison describes him — had beaten King to publication? Consider how different our first impressions of a Gibraltar Woman might have been from those of Neanderthal Man: what feelings of sympathy, or even kinship, this other skull might have stirred.

There is a worldview, the opposite of Joachim Neander’s, that sees our planet as a product of only tumult and indifference. In such a world, it’s possible for an entire species to be ground into extinction by forces beyond its control and then, 40,000 years later, be dug up and made to endure an additional century and a half of bad luck and abuse.

That’s what happened to the Neanderthals. And it’s what we did to them. But recently, after we’d snickered over their skulls for so long, it stopped being clear who the boneheads were.

I’ll start with a confession, an embarrassing but relevant one, because I would come to see our history with Neanderthals as continually distorted by an unfortunate human tendency to believe in ideas that are, in reality, incorrect — and then to leverage that conviction into a feeling of superiority over other people. And in retrospect, I realize I demonstrated that same tendency myself at the beginning of this project. Because I don’t want to come off as self-righteous, or as pointing fingers, here goes:

Before traveling to Gibraltar last summer, I had no idea what Gibraltar was. Or rather, I was sure I knew what Gibraltar was, but I was wrong. I thought it was just that famous Rock — an unpopulated hunk of free-floating geology, which, if I’m being honest, I recognized mostly from the Prudential logo: that limestone protuberance at the mouth of the Mediterranean, that elephantine white molar jutting into the sky. True, I was traveling to Gibraltar on short notice; when I cold-called the director of the Gibraltar Museum, Clive Finlayson, he told me the museum happened to be starting its annual excavation of a Neanderthal cave there the following week and invited me to join. Still, even a couple of days before I left, when a friend told me she faintly remembered spending an afternoon in Gibraltar once as a teenager, I gently mansplained to her that I was pretty sure she was mistaken: Gibraltar, I told her, wasn’t somewhere you could just go. In my mind, I had privileged access. I pictured myself and Finlayson taking a special little boat.

In fact, Gibraltar is a peninsula connected to Spain. It’s a lively British overseas territory, with 30,000 citizens living in a city on its western side — a city with bakeries and clothing stores and tourists buying all the usual kitsch. Some unusual kitsch, too — like a laminated child’s place mat I spotted that, in a typical tourist destination, might say something unexceptional like SOMEONE WHO LOVES ME WENT TO GIBRALTAR, but here read WE SHALL NEVER SURRENDER! BRITISH FOREVER!

The history of Gibraltar, given its strategic location, is a grinding saga of military sieges and ruthlessly contested changes in ownership. The residue of that strife, today, is a pronounced British patriotism and a never-ending exchange of slights with Spain, which still disputes Britain’s claim to the territory. After Queen Elizabeth II’s Diamond Jubilee, in 2012, when Gibraltar projected towering images of Her Majesty on a Spain-facing side of the Rock — “a clear act of provocation,” one reporter called it — Spain began inspecting vehicle after vehicle at the border, backing up the line for hours, stranding the bulk of Gibraltar’s work force, who commute in every day. The afternoon I showed up, activists from a far-right Spanish political party had crossed into Gibraltar and hung an enormous Spanish flag high up on the Rock. This wasn’t just mischief. It was regarded as an act of symbolic terrorism. When one of the men appeared in court two days later, I read, a woman screamed at him, “Gibraltar will never be Spanish!” She sounded like that defiant place mat come to life.

I happened to arrive in Gibraltar the week of the Brexit vote. Up in England, people were thundering about the working class versus elites, sovereignty and immigration, warning that British identity was being fouled by the European project. But in Gibraltar — a far-flung, fully detached nib of Britain, flanked by water on two sides and Spain on the third — the question was less philosophical: If the United Kingdom left the European Union, Spain might seize the opportunity to isolate Gibraltar, leaving the territory to shrivel up, like a flap of dead skin. The Gibraltarian government had already called on the House of Commons for help. There was concern that Spain would jam up the border again and that it might happen right away.

Around town, “Remain” signs hung everywhere. The atmosphere was edgy, as though everyone was holding hands, waiting to see whether a meteor would hit. It was like the hairline cracks between so many self-designated Us-es and Thems seemed to be widening, and some corrosive, molten goop was seeping out: mutual dependence curdled with contempt. Clearly it was happening back home in America too.

All in all, it was a good week to spend in a cave.

The openings to Gibraltar caves, including Gorham’s and Vanguard. 
Credit Jaap Scheeren for The New York Times

Gorham’s Cave is on Gibraltar’s rough-hewed eastern coast: a tremendous opening at the bottom of the sheer face of the Rock, shadowy and hallowed-seeming, like a cathedral. Its mouth is 200 feet across at the base and 120 feet tall. It tapers asymmetrically like a crumpled wizard’s hat.

Neanderthals inhabited Gorham’s Cave on and off for 100,000 years, as well as a second cave next to it, called Vanguard Cave. The artifacts they left behind were buried as wind pushed sand into the cave. This created a high sloping dune, composed of hundreds of distinct layers of sand, each of which was once the surface of the dune, the floor of the cave. The dune is enormous. It reaches about two-thirds of the way up Gorham’s walls, spilling out of the cave’s mouth and onto the rocky beach, like a colossal cat’s tongue lapping at the Mediterranean. Every summer, since 1989, a team of archaeologists has returned to meticulously clear that sand away and recover the material inside. “I realized a long time ago, I won’t live to see the end of this project,” Finlayson, who leads the excavation, told me. “But I think we’re in a great moment. We’re beginning to understand these people after a century of putting them down as apelike brutes.

Neanderthals are people, too — a separate, shorn-off branch of our family tree. We last shared an ancestor at some point between 500,000 and 750,000 years ago. Then our evolutionary trajectory split. We evolved in Africa, while the Neanderthals would live in Europe and Asia for 300,000 years. Or as little as 60,000 years. It depends whom you ask. It always does: The study of human origins, I found, is riddled with vehement disagreements and scientists who readily dismantle the premises of even the most straightforward-seeming questions. (In this case, the uncertainty rests, in part, on when, in this long evolutionary process, Neanderthals officially became “Neanderthals.”) What is clearer is that roughly 40,000 years ago, just as our own lineage expanded from Africa and took over Eurasia, the Neanderthals disappeared. Scientists have always assumed that the timing wasn’t coincidental. Maybe we used our superior intellects to outcompete the Neanderthals for resources; maybe we clubbed them all to death. Whatever the mechanism of this so-called replacement, it seemed to imply that our kind was somehow better than their kind. We’re still here, after all, and their path ended as soon as we crossed paths.

But Neanderthals weren’t the slow-witted louts we’ve imagined them to be — not just a bunch of Neanderthals. As a review of findings published last year put it, they were actually “very similar” to their contemporary Homo sapiens in Africa, in terms of “standard markers of modern cognitive and behavioral capacities.” We’ve always classified Neanderthals, technically, as human — part of the genus Homo. But it turns out they also did the stuff that, you know, makes us human.

Neanderthals buried their dead. They made jewelry and specialized tools. They made ocher and other pigments, perhaps to paint their faces or bodies — evidence of a “symbolically mediated worldview,” as archaeologists call it. Their tracheal anatomy suggests that they were capable of language and probably had high-pitched, raspy voices, like Julia Child. They manufactured glue from birch bark, which required heating the bark to at least 644 degrees Fahrenheit — a feat scientists find difficult to duplicate without a ceramic container. In Gibraltar, there’s evidence that Neanderthals extracted the feathers of certain birds — only dark feathers — possibly for aesthetic or ceremonial purposes. And while Neanderthals were once presumed to be crude scavengers, we now know they exploited the different terrains on which they lived. They took down dangerous game, including an extinct species of rhinoceros. Some ate seals and other marine mammals. Some ate shellfish. Some ate chamomile. (They had regional cuisines.) They used toothpicks.

Wearing feathers, eating seals — maybe none of this sounds particularly impressive. But it’s what our human ancestors were capable of back then too, and scientists have always considered such behavioral flexibility and complexity as signs of our specialness. When it came to Neanderthals, though, many researchers literally couldn’t see the evidence sitting in front of them. A lot of the new thinking about Neanderthals comes from revisiting material in museum collections, excavated decades ago, and re-examining it with new technology or simply with open minds. The real surprise of these discoveries may not be the competence of Neanderthals but how obnoxiously low our expectations for them have been — the bias with which too many scientists approached that other Us. One archaeologist called these researchers “modern human supremacists.”