alt Hacker News> A computer genetic algorithm run for a billion generations doesn't lead to anything anywhere near the the complexity of a human.
What?... Our computers can't simulate anything similar to a real world. You're comparing apples to galaxies.
> meaningful loss of fitness
What makes you think we don't have "loss of fitness" already?
150 years ago child mortality was around 30% in the developed world, now it's less than 1%. A lot of kids with weak health survive now. I'm one of them - I got pneumonia when I was ~2 y.o. and probably would have died without antibiotics. Then I had something which required antibiotic treatment pretty much every year. My wife also had a pneumonia in early childhood. And so did my daughter...
Why do we need to talk about some mysterious problem in 10 generations when modern medicine removes a lot of fitness pressure by itself?
It's a very common misconception that "survival of the fittest" means something related to physical fitness or stamina. It does not, in fact it's almost tautological. It means only "survival of those most likely to survive."
Natural selection is still fully in operation, but the things being selected for may have changed. Whatever they are now, they are still being selected for. Those most likely to reproduce are those whose who reproduce the most, and whatever those characteristics are, they will be the ones that become more prevalent.
It's also very important to remember that this operates over hundreds of millennia. Human beings changing substantially will not occur within a period of time less than that. You'd need to look back into deep prehistory to find changes to humans attributable to natural selection. Changes to modern humans are all explicable through changes to nutrition and lifestyle, not through evolution.