Thursday, March 11, 2021
Ears and wings
Random thought mode this morning.
Humans are closer to birds than other mammals in many ways. Bipedal, use tools, use language and music. Even the shape and orientation of our head is more birdy than mammaly.
Another resemblance: Lack of pinnas. (Triggered by the beautiful painting of an early dinobird on her nest.)
Most mammals have big movable ears that they use intelligently for active direction-finding and for gestures. Most birds have no pinnas at all. Owls may be the only exception.
Humans are closer to birds on this measurement. We have vestigial flat pinnas that help slightly with localizing, mainly by filtering frequencies differently at different angles. This effect isn't important and we can get along without it. We can't rotate our ears like antennas, and we can't use them for gesturing. Like birds, we use vision almost exclusively, with hearing and smell as auxiliaries.
Most people dream of flying. Myths and stories and attempted inventions are eternal. We want to be full-fledged (heh) birds. We didn't actually leave the ground until we switched from bird-style flapping to squirrel-style gliding with power assistance.
How did this similarity happen? HGT? Reactivation of a gene that was turned off for most other mammals?
Labels: Asked and badly answered, Grand Blueprint
¶ 5:43 AM
