A couple of comments from a non-biologist. It seems to me that this is an example of a common pattern in biological research. A simple explanation is developed

A couple of comments from a non-biologist. It seems to me that this is an example of a common pattern in biological research. A simple explanation is developed for a phenomena, but then as time goes on, it turns out that in at least some important ways things are much more complicated than originally thought. Also, the article talks about the controversy between the view that all genes make tiny causal contributions versus some are core and other peripheral. But perhaps it is, at least in some cases, a matter of what I would call complex conditionality. So for instance maybe disease X happens if there are mutations in genes A, B and C, or C, D and E, or G, H and I, but not any other combination. Certainly we find things like that in other areas of reality.