Text Versus Subtext

(Warning: this post contains some journalistic/blogging inside-baseball material.)

Back in the dark ages (otherwise known as the 1990s), writing about science felt a bit like putting messages in a bottle. I’d write an article, a few weeks or months later it would appear in a magazine, and a few weeks or months later I might get a response from a reader. In some cases, an expert might point out an error I made. In other cases, she or he might explain the real story which I had missed. The delay could make for some disconcerting experiences. The first time I met the late Stephen Jay Gould, to interview him for a book I was working on, I was still lowering myself into a chair when he began complaining about the cover headline to a story I had written about fossil birds over a year beforehand. I stared at him blankly for a while as I reached back into my memory banks to figure out what he was talking about.

It’s much better these days, now that people can hammer me with emails seconds after my stories is are published. Science is a murky, complex endeavor, and my job has never stopped feeling like an apprenticehip, as I learn from mistakes.

But this new arrangement comes with a downside. Some criticisms are unjustified, and instead of simply emailing me these complaints, people sometimes decide to publish them for all to see.

John Hawks, an anthropologist at the University of Wisconsin, has done just this. He has written a long complaint about an article I wrote for the latest issue of Discover. The issue celebrates the 25th anniversary of the magazine, and it contains a series of two-page spreads that take a look at different fields in science and where they’re headed. The editors asked me to contribute a piece on human evolution. I included an interview with Tim White of Berkeley, an essay on the growing role of scanning in studies on hominid fossils, and a large graphic showing how scientists used CT-scans to reconstruct the skull of Sahelanthropus, the oldest known skull of a hominid.

Hawks makes a series of complaints about the piece, but rather than sticking to the article itself, he tends to focus on the "subtext," which he alone has the mysterious power to read. For example, the subtext apparently says that "anything high tech must be better." I never made such a claim, and it would have been silly for me to add a disclaimer to that effect: "Warning–not all things high tech are better." Healthy skepticism is certainly a virtue, but Hawks is ignoring the fact that the entire issue is dedicated to promising new scientific developments. (Here’s an article on research on using lasers in art conservation. I suppose Hawks would complain that the article didn’t mention that lasers can also kill people.)

When Hawks does actually deal with the article itself, he makes some serious mistakes. He mocks the conclusion of my piece, in which I describe some new applications of fossil scans–such as reconstructing wounds, simulating hominids walking, and making the scans available online to other researchers who can’t see the originals. "So utopian," he sneers.

As evidence, he turns to my interview with Tim White, in which White talked about the importance of other kinds of technology to the study of human evolution–such as the global positioning system, advances in dating fossils. "No CT scans there," Hawks declares.

Hawks shouldn’t argue from the absence of evidence. Actually, White talked to me at length about the promise of CT scans, including some of the applications I mentioned in the article. It would have been redundant to include his comments. Hawks may not be impressed by scans, but he shouldn’t count White on his side.

So why isn’t Hawks impressed with scans? For one thing, scientists can make mistakes with them, producing recontructions as biased as any handmade reconstruction. "The principle of ‘garbage in, garbage out’ is everlasting," he says.

True, but so what? I remember the same argument being made in the 1990s, when some biologists were starting to reconstruct the tree of life by using computers to analyze DNA sequences and morphological features, rather than relying on a more intuitive sense of what evolved from what (a method known as cladistics). Critics warned that the cladists were just dumping bad data into their computers, and so their conclusions couldn’t be trusted. In fact, the cladists were producing testable hypotheses with explicit assumptions that anyone could challenge. Of course there are cases in which this approach may face problems (in comparing populations of the same species, for example, or species that can swap genes, for example). But that hasn’t stopped cladistic trees from becoming the standard for the field. The garbage-in-garbage-out complaint is equally beside the point when it comes to predicting the importance of scans to the study of human evolution.

Descending again into my subtext, Hawks writes that "a read of the article gives the impression that every finding from this new advanced technology supports splitting hominids into several species." If I may indulge in a little subtext-divining myself, I think we’re getting somewhere now. Hawks is a long-time proponent of the idea that too many hominid fossils have been designated as separate species. It just so happens that a couple of recently published scans–one of Neanderthal children and one of the "Hobbit" brain–have been interpreted by the authors of these studies as supporting the idea that these fossils do not belong to humans, but to other species. But instead of directing his wrath at these scientists, Hawks directs it at me. In order to do so, however, he has to ignore the fact that I write about many other applications of scans that don’t support splitting hominids into several species.

Hawks is perfectly entitled to attack hominid-splitting (and on his blog he has done a great job of documenting new research that supports his attack). But I don’t appreciate him distorting my own writing to serve that agenda. It’s particularly unfair to do so when most people haven’t had a chance to read the article for themselves, and have to rely instead on Hawks’s misleading summary.

Update, Wed. 1pm: Another improvement on the dark ages: when I attack, the attackee can respond. John Hawks defends his post in the comments. I agree that CT scans of hominid fossils are not now being freely shared on the net. But I think there’s reason to be optimistic–see, for example, the Digimorph Project, which is building up a big database of scans of bones from living and fossil animals. Would it have been utopian to predict Digimorph a decade ago?