No One's Perfect. Really

At Genetic Future, Daniel MacArthur follows up on a Nature article from yesterday that looked at what experts think will happen in reproductive medicine over the next 30 years. He agrees with Susannah Baruch, in saying that the genetics behind complex traits will never allow us to pick a perfect embryo simply because the chances of getting one are "once in every 10²² attempts (that's a 1 followed by 22 zeroes, a stupidly large number)," writes MacArthur. Instead, we'll know everything about the genetic makeup and will have to pick from among these. "That's not to say that embryo selection is unworkable -- in fact, I think it's inevitable -- but rather that this process is likely to require a degree of agonising trade-offs on the part of parents-to-be that is seldom fully appreciated."