Rare and Superior Gene Variants

It turns out that there’s a rare variant of a gene involved in Alzheimer’s Disease that protects the carriers against age-related cognitive decline.  It even, apparently, protects against other known genetic risk factors for Alzheimer’s.  This is totally the kind of thing I can imagine parents paying big bucks to have inserted into their kids — rare genes that already exist in the broader population, that confer disease resistance or other advantages, but which haven’t had time to become prevalent under natural selection, or which confer an advantage that won’t have obvious reproductive consequences.  We’re going to start accumulating a library of these potential genetic revisions and, I suspect, within a couple of decades, making sure that our descendants carry them disproportionately.