>>14017295>>14018590You're looking at it from the wrong angle. You're thinking that there must have been something like a lizard that one day gave birth to a full on bird, with feathers, hollow bones and front/upper appendages stretched into a perfect shape for flight.
But all you need to do is look at flightless birds to see some (!) of the intermediary steps. They cannot into flight but can into jumping and flapping, sometimes even gliding for a bit. That's useful. That improves their fitness. So that stays.
And since it stays and allows them to spawn greater numbers with this upgrade, RNG throwing shit at a wall to see if something sticks goes to work again. Some develop gliders that are too fragile and don't breed as much. Some develop legs so powerful they just can coast on that, grow into proper swole fucks, and at some point even win against a British prison colony. But some eventually hit all the right spots and their flapping while gliding lets them stay up longer.
Tl;dr: very small steps over very long time, with many, many branches at each step being dead ends.
