Well, designed is the wrong word. "Did not eliminate in a process of successive mutations" is more accurate.
1[anonymous]
Yes. But it took 3.5 billion years and we had to sacrifice teeth, claws, big muscles, running fast, toxic weapons, immune system strength, flight and a lot of other things, and we are still broken as hell.
Go fig. Go read an evolution textbook.
[I know that 'sacrificing' is not factually true, but it illustrates the point well]