Here's the Bulletin of the Week (or, at least, Day) from
Let's shake on it--it's a big deal...isn't it?
That the handedness story
Actually, what this study really shows, once and for all, is a fundamental fact about modern genetics:
The left hand doesn't know what the right hand is doing!**
* We add a caveat that the study suggests. They were able to analyze a mere 3940 twins, so could only detect genomic single-SNP effects with an odds ratio of 2.0. It could not detect sites with an OR of 1.2 or less. The point, of course, is to provide an advance justification for anyone to propose a gargantuan meta-analysis of, say 100,000 twins, to detect the grains of sand that contribute to this vitally important trait.
** And apparently the right hand doesn't know what the right hand is doing here! This story is in Heredity, not Nature! Our mistake, thinking the BBC only picks up Nature/Science stories!