Paleoanthropology: Start Over?
The September issue of National Geographic, featuring the African continent, has arrived in homes. On page 1, Joel Achenbach of the Washington Post wrote about the quest for early man, asking, “Are we looking for bones in all the right places?” The bulk of the article describes the “messy” story of human origins. It used to be clean-cut, he said, but no longer:
Scientists are good at finding logical patterns and turning data into a coherent narrative. But the study of human origins is tricky: The bones tell a complicated story. The cast of characters keeps growing. The plot keeps thickening. It’s a heck of a tale, still unfolding.
More than half a century ago the great biologist Ernst Mayr surveyed the field of paleoanthropology and saw all sorts of diverse characters: Peking man, Java man, and Homo erectus. He figured out that they were all the same thing and helped bring coherence to a rambling tale. By the 1960s the textbook version of human origins looked pretty tidy: Humans evolved in Africa; Homo habilis begat Homo erectus, who begat Homo sapiens. (The Neandertals were sort of a fly in the ointment.) Today the field has again become a rather glorious mess. (Emphasis added in all quotes.)
That represents the bulk of the article: the simple picture is gone, we don’t know who begat whom, we have no fossils of chimpanzees, the family tree is full of dead ends, and we may be trying too hard to tell a story from too few bones. Achenbach quotes Dan Lieberman of Harvard: “We‘re not doing a very good job of being honest about what we don’t know. Sometimes I think we’re trying to squeeze too much blood out of these stones.”
Achenbach also contrasts the study of human evolution with the classical hard sciences:
Earth doesn’t yield a perfect database. Still, it’s our scientific impulse to impose parsimonious explanations on complex problems in the same way that Newton realized that the fall of the apple and the motion of the planets were governed by the same simple force called gravity. But the process of evolution can’t be observed like the fall of an apple. Life—despite all the efforts of modern science—is messy.
One might be tempted to conclude, therefore, that the field is open to alternative explanations. Why, then, does Achenbach put this statement in the middle of his article? “The central fact of human evolution is a given—humans descended from a primate that lived in Africa six or seven million years ago—and those who would doubt evolution are arguing against the entire enterprise of science.” The basics are established, he claims; it’s only some key details that are unknown.
Is it any wonder why Achenbach wins Stupid Evolution Quote of the Week? Look at what he did. He demolished everything most of us were taught as evolutionary fact years ago. He admitted that the whole picture is a mess of disconnected, confusing pieces. He admitted that no one can make sense of it. He admitted that paleoanthropology is not in the same ballpark as Newton’s hard science, and why?—because “the process of evolution can’t be observed like the fall of an apple.” There aren’t enough ape bones, there aren’t enough human bones, and there aren’t enough bones of anything in between that is not controversial. On top of all that, we might even just be imposing our own preconceptions on the data! He quotes someone who casts doubt on the honesty of paleoanthropologists. That seasoned veteran of the “science” of paleoanthropology believes the researchers are trying to squeeze too much blood out of their bones.
In short, Achenbach has just shorn paleoanthropology of any claim to legitimate science. Yet in the midst of this doleful tale of ignorance, he commits the most egregious logical fallacy imaginable. (1) First, he bluffs with his made-up story that humans evolved out of Africa six or seven million years ago – how does he know? Did he observe this? On which bones did he base this belief? Ignoring the fact that the out-of-Africa view is controversial, even if the leading candidate for the “thickening plot,” he instructs us that this belief is not open to question: “the central fact of human evolution is a given.” (2) Second, like a stingy hyena unable to eat but snapping angrily at anyone approaching the carcass of a dead science, he says, “those who would doubt evolution are arguing against the entire enterprise of science.” So creationists, keep out; this is our storytelling game, he implies. Fine; if your view of science is bluffing, ignorance, open-ended storytelling and authoritarianism, you can have it.
The plot keeps thickening, he says. It’s the enterprise of science, he says. The Science Restaurant used to be a nice place to hang out before Chef Charlie swindled the owners and took over. He replaced everything on the menu with the only thing he knew how to cook, his original Thicken Plot Pie, which has become so thick now it should only be taken with a strong laxative. It’s understandable why Achenbach, moaning in discomfort, is envious of Newton and his—shall we say it?—“regularity.”