four-legged flyers? or maybe not.
So it’s not true that all science is physics or stamp collecting. Sometimes, it’s creative writing.
When it comes to studying ancient birds, it’s often necessary to make a few assumptions and hope that future evidence will support your theories. Sometimes taking that leap can jumpstart what is “known” and help people see what is actually there. It’s awfully easy to overlook important, obvious, and often totally banal evidence that’s lying in the dirt when you’re required to, well, stand on the shoulders of so many giants.
Birds have been around for longer than we can really even fathom, and sometimes it takes a creative leap to look around the existing wisdom and suggest something new. The back and forth chatter between the Arboreal and Thecodontal theorists have probably done more to harm progress in this field than anything; when you’re busy defending a theory in a hot and public argument, you’re hardly open and receptive to new evidence.
I particularly enjoyed this suggestion of the importance of hindlimbs in flight evolution, from a PhD student at the University of Calgary. It’s creative and a bit daring, and it’s getting press, too. Good work.
That said, and while I have yet to read the full paper, the thesis still doesn’t ring quite right to me. Anything has aerodynamic properties, if you throw enough wind at it. And there’s a kind of economy of form common to all living things; volume: surface area ratios must exist within certain tolerances, and the presence of skin over muscle and tissue tends to follow a pretty specific set of curves. And I’d love to hear more scientists discussing that economy of form; observing it where it is alive in the ancient species of today. You cannot watch a flightless cormorant without the realization that you are looking through an open window, one that opens on hundreds of thousands of years into the past.
It’s easy to toss rocks at the longstanding work of many devoted and educated scholars, and I certainly don’t want to do that. But I do believe the viability of existing theories would be greatly enhanced through closer observation of extant, living and breathing birds.
The abstract is here.