Friday, April 9, 2010

The newest newest newest transformative fossil fills the gap....but not the credibility gap

Here we go again. As reported in Science, and commented on by the BBC , and in fact all over the news, more hominid fossils -- two specimens -- have been found!! These, in south Africa 'might be' a new species says the discoverer. Why? Because they isn't just like other fossils known. Naturally.
Researchers tell the journal Science that the creatures fill an important gap between older hominids and the group of more modern species known as Homo, which includes our own kind.
What else can they say if they want to be in the news? Hey, says CNN, it's a "time machine", it "sheds new light". And it's no surprise that the investigators have already, unilaterally decided on its name Australopithecus sediba. The problem here is not that the finds aren't potentially important and informative, nor that they come from a sparsely represented part of human ancestry. It's the melodramatizing of the term species.
"It's at the point where we transition from an ape that walks on two legs to, effectively, us," lead scientist Professor Lee Berger of the University of the Witwatersrand told BBC News.
The time period is 1.8 to 2.0 million years, but calling it a 'point' reflects the issues. Morphological change would likely have been very gradual (even this 'point' is given 200,000 years, or 10,000 generations--roughly twice the age of our human species.

Naturally it doesn't look just like other things that distant from us or each other. It's a "fascinating mosaic" of features said one person interviewed. Another says that rather than putting it in Australopithecus, 'certain features' suggest it was really Homo. But these are entirely subjective cutoff points. Indeed, even the species concept itself is vague in many cases. And Homo vs Australopithecus is a genus, not species distinction, and that is entirely human-imposed (not natural categories). Since this is basically an evolutionary continuum, it's good for the paleontology business to be able to argue about the distinctions even if they have little meaning.

Holly is away actually doing some science of her own (presenting research at two meetings) but she expects to provide you with some entertaining (and cogent) comments on the finds themselves when she gets back home. She's an expert, and she may see things more stunning than estimates of the fossils' age at death, how tall they were, and that they 'may have' been somewhat stronger than Lucy (3 Myr old). Give us a break!

The idea that we find something from a poorly represented time gap, morphology not exactly seen before, doesn't make this dramatic news. It may well be quite interesting to paleoanthropologists, but it can't overturn what we already know, and the proliferation of species names is not helpful (because it's so subjective) and hence it's a problematic reason to blare out yet another most-important fossil news extra.

By pretending that every investigator and every 'find' is, like the children in Lake Woebegon, above average, we turn all science into vanilla, making it hard to know what's really noteworthy and worth following up with more research. Of course, to some extent this is yet another intentional aspect of our current science and science-funding culture, besides the investigators' understandable personal investment and satisfaction and ego in their results. It's part of the lobbying process.

That magazines like Science and Nature are hungry for these Big Stories makes them less trustworthy as serious science journals, a view widespread even among those who, for personal career reasons, hunger to be published there. By making them into the go-to places, even if it's often as much circus as science, undermines other journals, where most of these stories properly should go to nurture the various areas within science.

Science needn't be boring, but one can take great interest in such fossils without insisting that they are profoundly revolutionary. Living on steroids is exhausting. Instead, if we had a proper understanding of science, and the phenomena of Nature, interest alone should be enough.

1 comment:

Holly Dunsworth said...

This reads like a pregame locker room speech and I really needed it this morning! Thank you Ken and Anne. Now I'm off to lecture about how tall and strong the Nariokotome boy was and also his age at death and cause of death. No breaks given on that one ;).