By Ken Weiss
The Mermaid’s Tale
In 1926, geneticist Thomas Hunt Morgan wrote this about stature:
A man may be tall because he has long legs, or because he has a long body, or both. Some of the genes may affect all parts, but other genes may affect one region more than another. The result is that the genetic situation is complex and, as yet, not unraveled. Added to this is the probability that the environment may also to some extent affect the end-product.
(TH Morgan, The Theory of the Gene, p 294, 1926):
His point, of course, was not about stature per se but about the difficulty of identifying genes ‘for’ traits because there are many pathways to a trait, and they aren’t all genetic. This was understood eighty-eight years ago, and yet we have had study after study, ever larger, merging smaller studies, and all sorts of fancy statistics to account for various internal complications in genome sampling, and still the results pour forth as if we haven’t learned what we need to know about this and many traits like it.