> why don't we see them in the independent evolution of life Because evolution is a very weak optimisation process. It has very limited materials to work with

> why don't we see them in the independent evolution of life Because evolution is a very weak optimisation process. It has very limited materials to work with - everything has to be made of meat. The only changes it can make are incredibly indirect ones - mutations in DNA base pairs, leading to different proteins being manufactured or some such (I'm not a biologist, obviously) leading to subtle changes in the makeup of the resulting organism. Can you imagine how difficult engineering would be through a medium like that? It'd be like trying to perform brain surgery with a sledgehammer. And it's not even purposefully optimising for anything, let alone intelligence. The changes all happen completely at random, and the ones that manage to reproduce stick around. Moreover, the fact that such a weak process as natural selection can produce something as smart as us, should really make you consider that humans, with optimisation power far superior to natural selection, can produce something far smarter.