> you would have to show is that there is some bone or ligament or muscle or feather or something else, where if you replaced it with a plastic/mechanical/etc v

> you would have to show is that there is some bone or ligament or muscle or feather or something else, where if you replaced it with a plastic/mechanical/etc version with the exact same properties and behavior, the flying system w=could no longer function "the same" Yes. This implies that you can measure the properties of the system you intend to recreate, and reproduce them at a high enough fidelity. The core of my rebuttal is that we might not be able to a) measure all the properties that matter and/or b) recreate them with enough fidelity for certain categories of problems. Bones, we're good. Neurons at extremely large scales? I wouldn't bet either way. > Science doesn't really have a strong incentive to try to exactly copy the mechanics of a pigeon with plastic components and plastic feathers and ligaments and some kind of muscles, and trying to get it to be composed exactly the same way. Other than a novelty, it doesn't really "get us" anything. It could get us drones that would fly 10 months without landing. Science doesn't really get much stronger of an incentive than "the military wants it".