Pork barrel paleoanthropology

6 minute read

A weblog is a monologue. I try to keep this in mind whenever I post on a topic where I have an opinion. If I wanted to, I could just browbeat ideas I don't like. But that wouldn't be very useful to people trying to get a general idea of the science, and it certainly wouldn't be very interesting.

Now don't get me wrong: I have certain pet peeves that lower my impulse control on the "post" button. And long experience teaching had taught me that hiding my opinion isn't honest or interesting, and is only rarely useful.

However, the presence of an opinion isn't a difference between the weblog and a journal article. Research articles certainly have an opinion, and they almost always further an agenda. What's worse, that agenda attains a privileged status in a journal, because opposing it requires more than simply pointing out its flaws --- it requires putting together a research article to overturn some part of the result. In other words, the publication process exerts a cost on scientific logic.

This cost is analogous to the cost of parliamentary process on legislation: essential items are combined with each other into "omnibus" bills that include lots of nonessentials put in to make certain legislators happy. In American tradition, these nonessential costs of doing legislative business are called "pork". This combination of stuff makes it easier to pass bills through legislatures, but it is not the most efficient use of public money.

Science is the same way. Like legislation, research articles are larded well with nonessential items: people cite their friends, try to make their limited conclusions apply to broader questions, and add irrelevant references to pet ideas. But also, research articles deliberately lack things that --- in the ideal scientific argument --- ought to have been there, like discussion of alternate hypotheses that may explain the results, relevant work in analogous fields, and (most importantly) conceptual weaknesses in Sometimes these omissions and extras are caught by peer review and amended. But it's too much trouble to catch them all, especially if they follow a well-worn agenda from prior papers. So science is full of pork.

Paleoanthropology is among the worst, because so many different stakeholders contribute to the work: anthropologists, archaeologists, geneticists, geologists, and so on. Much of the process of training our students is getting them to understand which parts of research articles are essential and which parts are pork. Just like a legislative intern, they have to learn which people are served by which concessions --- a tangled mess that is fully as ideosyncratic as bridge projects in congressional districts. So we have stories about "lumpers" and "splitters", and we keep track of who advised whom, and who worked at whose field site (or wants to in the future) and who went to which meeting. Students quake in fear about who might be on grant review panels and who might review our papers, and they include things in grant proposals and articles that they don't really think in the hopes of getting accepted. And some of all that quaking is really good for the science, because sometimes students ought to consider things they don't really think, or do tests they really don't want to do. On the other hand, sometimes it's just in the service of pork.

But for the student who doesn't have the time or inclination to work out all these intricate relationships, there is an alternative strategy: just don't read the articles at all! This is by far the most common way of working in paleoanthropology; reading nothing at all in a research article except for the abstract and the conclusion. The field is small enough that this strategy doesn't work very well --- we are pretty strongly K-selected, and students who ignore certain things do so at peril to their careers. But in genetics, there are a lot more students, a lower proportion of them will stay in the field for long, and there is a much shorter research cycle. For the most part, even the reviewers haven't read very much about human evolution. So the things that do get cited and the arguments from anthropology that are presented are highly idiosyncratic. It can be hard for an anthropologist to understand why what seem like essential issues have been completely ignored. When this research comes back into anthropology, to support ideas in an anthropological article, the context of all that pork barrel thinking is completely lost. All that is left is the impression that genetic data "support" some hypothesis about human evolution, without consideration of all the alternative hypotheses that have been left out of the discussion.

The long publication process in journals blunts criticism. Some journals don't even accept letters to the editor (!), and those that do so tend to limit their publication to methodological comments rather than smaller issues. So it is effectively impossible to cut the pork. This has certain advantages for authors, in that it lets them publish things they can't really support. It has clear disadvantages for comprehension, because people outside the process cannot evaluate the basis for conclusions. There is no transparency, in other words --- almost as if paleoanthropology were a priesthood instead of a science.

Don't misunderstand me; if I didn't think paleoanthropology was science, I wouldn't do it. And I think we are, if anything, more critical of certain kinds of logical inference than most other fields --- mainly because the limited nature of our evidence necessitates it. How many other parts of biology have had as detailed an exploration of the nature of species as paleoanthropologists?

But certain kinds of inferences go a long time in this field without being challenged, even when the evidence that supports them is weak, absent, or (worse) circular. How many articles have cited the mtDNA coalescence time as evidence about human origins without any mention of the word, "selection"? After six decades of research on the species problem, how many still make conclusions about reproductive isolation after applying species concepts not based on reproduction?

In a year or so of writing the weblog, I've learned that I can't get away with pork barrel thinking. When I write things that I can't support, my readers let me know, usually within a few hours. This is as true of minor errors as it is of major misinterpretations. Sometimes you will see rapid follow-up posts here, or updates on posts. These almost always come from reader comments. As critically as I treat ideas that I discuss, you can believe that readers are treating me just as critically. No one in science holds opinions lightly, but mine are beholden to a very large sample of critical readers -- many professionals -- who rejoice in letting me know when I'm sloppy. That means that I have to be transparent: I quote actual text, and link to original articles, so anyone can compare what I write to what the original article says.

I'm not writing up new research results here, or breaking any news. What I'm doing is reading things with due diligence, reflecting on results, and pointing out logical pork where I find it. It is already having an effect: it has informed my research, brought attention to papers in tangent fields that bear on human evolution, and has rattled a few cages. I think that this kind of work will only grow in importance: as paleoanthropology spreads to encompass the genome as a whole, there will need to be much more coordination of different fields with each other.

With your help, and especially your continued reading, I've created a new kind of resource. I just want to say I feel incredibly privileged to have such an active and interested readership.