Ancient Teeth–What They Mean and What They Say

Haim Watzman

Scientific papers are not generally thought of as allusive, but, as the article I wrote for Nature this week shows, intentional ambiguity is not foreign to the scientific world.

So are the eight ancient human teeth, some dated as far back as 300,000-400,000 years ago, that Avi Gopher of Tel Aviv University and his colleagues found in Qesem cave really evidence that Homo sapiens evolved here in Israel, as my friend and colleague Matthew Kalman wrote in the Daily Mail? Kalman based his story on Tel Aviv university’s press release, which Gopher vetted and by which he stands. Going out on a shorter limb, other reports in the mainstream press merely said that the discovery proves that modern humans evolved much earlier than the currently accepted 200,000 years before present.

As my article states, bloggers (such as Carl Zimmer and Brian Switek) who follow human evolution news jumped on the disparities between the press reports and the paper that Gopher et al. published in The American Journal of Physical Anthropology. The latter cautiously offers three alternative interpretations of the teeth.

But Gopher claims that university’s press release is accurate. How can that be?

Gopher derives his claim of accuracy from the paper’s conclusion that the group of finds that the Qesem teeth most resemble are a group of teeth from Skhul and Qafzeh caves in northern Israel, and that they bear some characteristics associated with Neanderthals. Those teeth, dated to between 80,000 and 120,000 years old, are often thought to be modern human precursors to Neanderthals, who were contemporaries of Homo sapiens—although that interpretation is not accepted by all.

So if the Qesem teeth are like the Skhul and Qafzeh teeth, and the latter are modern humans, then the Qesem teeth are evidence that modern humans—that is, Homo sapiens—evolved much further back than the current thinking has it. But that’s lots of ifs, all about not a lot of teeth. Gopher et al. were not willing to state that explicitly in their paper, and rightly so.

But when Gopher spoke to the university press office, he went a little farther, leading to the headlines.

The Qesem teeth are indeed a significant and fascinating find—but, on their own, they don’t prove anything so far.