<s>[INST] Why don't animals have wheels? Answer as briefly as possible. [/INST] Mechanistically because wheels are a human invention, and only a few animals have been invented by human. In general current modern technology is quite bad mergine biological and mechanical components in a way that is consistent with the animal's fitness curve. If by having wheels you mean only figuratevely, then domestic animals often have prostetic wheels as a consequence of surgeries and congenital problems which serverly impair their deambulation ability.</s>\ <s>[INST] Why did evolution never come up with wheels instead of legs? [/INST] I don't know, though my guess would be that wheels are rather complex compared to limbs and only work well on smooth surfaces.</s>