Obviously.
But surely you don’t wish to define evolution as “the getting of mutations”.
Sometimes, with sexual selection, maybe?
Well, it’s mutations plus a sorting mechanism, but what I’m trying to say is that the results are still incidental. There isn’t any intent.
A little, but sexual selection suffers from the same limitation as the rest of evolution; if a trait doesn’t happen to appear, then it has nothing to work with. It only selects, it doesn’t create. Something “cool” like metallic gold eyes might be really exotic and attractive, and a guy who had them might be able to seduce lots of women and leave lots of children - but without some mutation for metallic gold eyes randomly appearing in the first place, then sexual (or natural) selection can’t select for them.
Which of our ancestors should have evolved flying?
It’s fairly obvious the baby steps towards flying we’d have to take today, or back when we were chimplike even, would not be advantageous by themselves, as they’d need to be to be selected for. In fact we’re selecting against one of them right now. Flappy overarms anyone?
And why are there any non-flying animals at all?
Start answering this and you might find some reasons for us not flying.
Nm
The term ‘reason’ doesn’t have to imply intent. Moreover, I dont think anyone here was under the impression that it did.
Somewhere on an old hard drive, I have a pile of notes I put together for a short story about a man surgically modifying his body to be able to fly. I eventually gave up on the story, because the sacrifices the poor guy would have had to make would have been far too extreme to be believable.
His legs would have to go, except maybe for some vestigial stumps adapted into a tail-rudder construction.
Wings coming out of the back, angel style, just wouldn’t work because there’s no good way to anchor muscles strong enough to support them. If the wings could beat hard enough to lift a person, they’d just rip out of the sockets. So that means bat style wings to take advantage of chest and back muscles (both heavily augmented), which means extreme modification to the arms and hands.
Even after all that, I’m still not sure the math even supports the guy staying off the ground. And this is for a deliberate engineering job. Lack of flight seems to make perfect evolutionary sense to me.
I think if it wasn’t for agriculture someday some hominid species might of developed hollow bones at least. Hollow bones are good for running, would be a good benefit to a species that hunts by running it’s prey into exhaustion.
That’s it! The answer is “Agriculture”.
why haven’t we evolve photosynthesis. we should get maximal benefit of the sun.
Speculation: Maybe the surface area of the average human body wouldn’t be able to capture enough energy to power something our size? We’re typically quite a few trophic levels up, and we depend on concentrated energy gathered by animals and plants over large acreages.
We use the sun to photosynthesize vitamin D.
What about ‘hang’ time? Huh? Huh?
We wouldn’t (people have run the calculations), although it would have been entirely possible for us to develop photosynthesis as a supplementary energy source. Or to have developed a symbiotic relationship with some plant species to do it for us like some species have. Some microscopic plant species adapted to living just under the surface of the skin for example, or more interestingly some relative of grass growing in place of hair/fur.