Yes. One of the signatures of evolution/selection on a gene is it spreading far faster than any random walk. For a single variant to go from 0 to up to 30% in a

Yes. One of the signatures of evolution/selection on a gene is it spreading far faster than any random walk. For a single variant to go from 0 to up to 30% in a few thousand years is extremely fast, so that instance of human evolution was detected early on. But there are many other instances where it's a whole set of variants affecting a particular trait, all of which get slightly increased in frequency to collectively sculpt humans to their local environment; this is much harder to detect because the increase in each variant is much smaller. But it's still doable, especially with whole genomes, so look forward to more discoveries in the next few years.