from New Scientist
How to transform your arm into a wing
- 00:01 01 April 2008
- NewScientist.com news service
- Jeff Hecht
Daedalus used feathers and wax – and we all know what happened to his son when he flew too close to the sun. Instead, you could try surgery, says Samuel Poore, a reconstructive surgeon at the University of Wisconsin in Madison who has now described the steps that would be needed to transform human arms into wings.
It sounds like an idea that might come from the underground world of body-modders, who go in for filing teeth to points, implanting horns – and even more extreme modifications. But Poore studied the mechanisms of bird flight under Ted Goslow of Brown University, Rhode Island, before he began medical school and became interested in hand surgery.
A colleague remarked that Poore would never be able to apply his knowledge of bird anatomy to plastic surgery – and that set him thinking.
A functional wing is, sadly, out of the question. Humans lack the shoulder joint and massive muscles that millions of years of evolution gave modern birds. Wing loading is another killer requirement. Modern birds need at least a square centimetre of wing area for every 4 grams of body mass, so an 80-kilogram human would need two square metres of wing.
But an arm might be converted to a decorative wing. Poore suggests modelling it on the wing of Archaeopteryx, the earliest bird, which had a shoulder much closer to humans than the shoulders of better-flying modern birds.
Getting hands-on
First, fuse the outer set of wrist bones and the hand bones to create a bird-like carpometacarpus, the third bone in a chicken wing. The thumb remains free, like the alula that helps guide bird flight, but other fingers would be fused together.
Next, rearrange the muscle and skin to allow articulation of the new bone arrangement.
Things get tricky when it comes to feathering the wings. Hair grows in different skin layers to feathers and the two consist of different types of keratin. No one knows how to convert one to the other.
In case you were looking forward to getting all Birdy, it all adds up to more trouble than it’s worth, Poore concludes. If you want angel wings, go rent a costume.
“Humans should remain human,” Poore says, “while letting birds be birds and angels be angels.”
Journal ref: Journal of Hand Surgery, vol 33A, p 277