Almost like the gene piggybacked of another gene.

Ape has a gene that means he can't make vitamin C, but that doesn't matter because he gets it all from his diet. However he also has a bunch of useful genes that make him more successful and so him and his descendents do very well and thr defective vitamin C gene goes along for the ride?

Where does humans inability to make vitamin C fit into all this? I know we get vitamin C from our diet so it rarely becomes a problem unless you're on a ship or low food quality environment - and then scurvy happens. So there was no selective pressure to keep it working really, but was there a selective pressure to stop it working like point 2.

I.e. do animals rhat can synthesis vitamin C have to pay "an upkeep" to maintain the bodies ability to do so or something?

Does this mean wisdom teeth where being selected against until we got technologically advanced enough to be able to remove teeth? Is that why some people don't have any trouble with wisdom teeth at all or even come through.

I've always sort of wondered because somehow all 4 of my wisdom teeth came through fine with no problems.