Everyone knows birds descended from dinosaurs, but exactly how that happened is the subject of much study and debate. To help clear things up, these researchers went all out and just straight up built a robotic dinosaur to test their theory: that these proto-birds flapped their “wings” well before they ever flew.
Now, this isn’t some hyper-controversial position or anything. It’s pretty reasonable when you think about it: natural selection tends to emphasize existing features rather than invent them from scratch. If these critters had, say, moved from being quadrupedal to being bipedal and had some extra limbs up front, it would make sense that over a few million years those limbs would evolve into something useful.
But when did it start, and how? To investigate, Jing-Shan Zhao of Tsinghua University in Beijing looked into an animal called Caudipteryx, a ground-dwelling animal with “feathered forelimbs that could be considered “proto-wings.”
Based on the well-preserved fossil record of this bird-dino crossover, the researchers estimated a number of physiological metrics, such as the creature’s top speed and the rhythm with which it would run. From this they could estimate forces on other parts of the body — just as someone studying a human jogger would be able to say that such and such a joint is under this or that amount of stress.
What they found was that, in theory, these “natural frequencies” and biophysics of the Caudipteryx’s body would cause its little baby wings to flap up and down in a way suggestive of actual flight. Of course they wouldn’t provide any lift, but this natural rhythm and movement may have been the seed which grew over generations into something greater.
To give this theory a bit of practical punch, the researchers then constructed...