[reaperman]

Most bodily functions have evolved for a purpose - fever for fighting infections/etc. But it’s not really axiomatic that we’ve evolved optimally. A lot of things evolved to get us through the reproduction stage of life but our goals sometimes diverge from nature’s goals. There are plenty of obvious things we could fix about human evolutions:

- Human spinal cord is often poorly (minimally) adapted to walking upright. It “works” just well enough but the spinal discs can only just barely support the increased gravitational load between each vertebrae so herniation occurs easily and the lumbar curvature poorly supports weight/load as well. Huge reason so many people have back pain by 40. Strengthening the materials in the spinal discs to support higher compression loads would be a massive benefit, even though it has a low chance of increasing reproductive success, so wouldn’t get naturally selected for by evolution.

- Blind spots: vertebrate eyes evolved with the optic nerve going through the retina (surface light is projected onto near back of the eye). So the area where the optic nerve passes through cant see anything. This isn’t necessary. Cephalopod eyes evolved the optic nerve connection layer to be behind the retina rather than in front of it so they have no blind spot.

So yes, a lot of things that “fix” or “improve” something may make things worse in another way, but some things could be purely beneficial with no downside for most people.