Thursday night notes

I know, I know; I broke my promise about writing up my thoughts on the Nature paper. Even though I could probably write up something really fast, other bloggers have already done a great job putting it in scientific context, so I thought I’d take something of a different route. Outside of focusing on the study and what it says about evolution (specifically our own evolution), I thought I would write up a little piece about the history of ideas dealing with how humans came to be. We’re all familiar with creationism, but there are lots of other claims old and new about how humans came to be, and so I thought I’d go back to show how our ideas about human evolution are far-removed from the straight-line “March of Progress” model attributed to scientists by the likes of Jonathan Wells and other Disco Institute folks. In fact, the post could serve as a good primer for my other intended posts on human evolution (especially the evolution of early primates), which I’m going to have to split up being the field is so wide. I’ve got a textbook on Primate Behavioral Ecology coming in the mail (I got it for 3 cents!) this week, so that will certainly help. Anyway, I promise that tomorrow I will have something up about the new study and what it really means as far as our concepts of human evolution.

Also, I’ve been digging into Feduccia’s The Origin and Evolution of Birds, and so far it’s not terribly fulfilling. Feduccia seems to committed to the idea that birds did not evolve from small theropods that anything relating to dinosaurs being smart, active, or dynamic is discounted, Feduccia’s model of dinosaurs more resembling the swamp-dwelling lizards thought up by early 20th century scientists (i.e. hadrosaurs are referred to as being primarily aquatic). Being the book came out at the beginning of the feathered-dinosaur boom, Feduccia does address the filamentous feathers of some of the Asian theropods; they’re just collagen fibers, he says. Thus Archaeopteryx and Confuciusornis are grouped in as true birds, all dinosaurs having more avian characteristics being dissociated with them (although the reasons for convergences are not addressed thus far). Feduccia brings up various anatomical aspects of birds and dinosaurs to try and disprove the link, but his main weapon are the supposedly different digits in the theropod and avian hand. Birds are suppossed to have digits II-III-IV and theropod dinosaurs I-II-III, therefore proving there is not link (at least to the author). Why the digits are numbered as they are (and what happened to the bird’s digit #1, if it’s no longer there) doesn’t seem to be addressed. Most of the author’s support seems to come from his own research and that of Larry Martin (and one other scientist who’s name escapes me at the moment), but the fact that so much of the positive proof for a non-dinosaurian ancestry of birds comes from these three authors (often working in collaboration) makes me dubious. Likewise, Feduccia constantly names Kevin Padian, John Ostrom, Bob Bakker, and to a lesser extent Mark Norell, the book sometimes seeming more like an attack on the scientists than their ideas. Feduccia also snipes at paleontologists as a whole whenever possible, making statements of little consequence to the main arguments (i.e. that a movie producer spoke at an SVP meeting and another had a musical interpretation of dinosaur behavior) in an attempt to show paleontology almost as a kind of pseudoscience that relies on divination from ambiguous remains.

The early chapters of the book primarily strive to establish that birds are not descended from dinosaurs, and while Feduccia makes some good points here and there (like some criticisms of the cursorial hypothesis for the evolution on flight), most of it is so focused on removing dinosaurs from close relationships with birds that much else is lost. The book is lavishly illustrated, however, although many of the diagrams are old/outdated (many of the dinosaur and archosaur skeletons are from the first half of the 20th century in postures now known to be wrong), and I do hope that some of the later chapters dealing with birds after they have become established will be better. The very last chapter (which I read first) is little more than more than defense of the poor paleontological scholarship found in the first three chapters of the book. I should finish it sometime tomorrow or on Saturday, at which time I’m sure I’ll write up some more general thoughts on the book.