A Bird in Hand

The idea that birds are, in essence, the dinosaurs that didn’t die out is common in evolutionary circles today. Artists’ renderings of certain theropod dinosaurs routinely show feathers, beaks, and bird-like postures, even though notable problems with the dinosaur-to-bird hypothesis remain (see “Did Dinosaurs Turn into Birds?” for a detailed review of the topic). Not all evolutionists are convinced, however; for example, we reported last year on scientists who believe some “dinosaurs” (or, at least, creatures currently classified as such) are actually the descendants of birds. At the time, we quoted Oregon State zoologist John Ruben—an evolutionist, as far as we’re aware—who explained:

“We’re finally breaking out of the conventional wisdom of the last 20 years, which insisted that birds evolved from dinosaurs and that the debate is all over and done with. This issue isn’t resolved at all. There are just too many inconsistencies with the idea that birds had dinosaur ancestors, and this newest study adds to that. . . . Raptors look quite a bit like dinosaurs but they have much more in common with birds than they do with other theropod dinosaurs such as Tyrannosaurus. We think the evidence is finally showing that these animals which are usually considered dinosaurs were actually descended from birds, not the other way around. . . . Given the vagaries of the fossil record, current notions of near resolution of many of the most basic questions about long-extinct forms should probably be regarded with caution.”

Keeping that in mind, what’s the latest news on the dinosaur–bird connection? Japanese researchers report in the journal Science a project to better understand the development of digits in chicken embryos. In the past, some scientists have argued against a dinosaur–bird evolutionary connection by pointing out that chickens grow what were thought to be the equivalent of our middle three digits, while theropod dinosaurs had the equivalent of a thumb, index, and middle finger. Does that mean the evolutionary link doesn’t add up?

By moving around embryonic tissue in the embryos, the Tohoku University researchers found evidence that the previous research suggesting that birds have the middle three digits in their wings is wrong. To some researchers, this is apparently tantamount to solid evidence that birds evolved from dinosaurs. But by our reading, the research only shows how complex the developmental process is—and how poorly we understand it.

Alan Feduccia is a University of North Carolina–Chapel Hill evolutionary biologist who is an expert on the various theories of bird origins, and he has consistently pointed out flaws in the dinosaur-to-birds theory. “Something very complicated is happening,” he told ScienceNOW, “but renaming digit identity based on these findings would be extremely premature.” ScienceNOW quotes another evolutionary biologist who says the results should be “considered with some caution.”

Rather than providing evidence for dinosaur-to-bird evolution, the Tohoku University team is actually only disputing evidence against the dino-bird connection that was proposed by Feduccia and others over a decade ago.

What news coverage of the research conveniently ignores is that rather than providing evidence for dinosaur-to-bird evolution, the Tohoku University team is actually only disputing evidence against the dino-bird connection that was proposed by Feduccia and others over a decade ago. And even if their rebuttal were conclusive, the research says nothing about the “inconsistencies” John Ruben mentions. And if the majority of evolutionary scientists will ignore the problems in this single supposed example of evolution, where else are inconvenient truths neatly swept under a rug?