You can not have multiple non mixable complicated traits in a sexually reproducing population, without tricks like having each member have the complete code for all possible traits, and a varying gene that switches on one of them, which we observe in sexual dimorphism at not much otherwise.
But we do observe epigenetic traits—variations in gene expression based on environmental conditions, such as genes that act differently depending on how much exercise you get, or the level of testosterone in the fetal environment, or various other things.. D’Adamo’s claim here is that his typing groups are a combination of gene inheritance and gene expression, and his notion of “strategies” isn’t really the same as say, having a completely different way of digesting foods.
It’s more like identifying which places to store fat in first—something that (IIUC) we already know is heritable. The fact that fat gets stored isn’t changed, just how much, where, and how quickly. Something like that can make a big difference on a practical level to a person’s life, without being a particularly complex adaptation in itself.
But we do observe epigenetic traits—variations in gene expression based on environmental conditions, such as genes that act differently depending on how much exercise you get, or the level of testosterone in the fetal environment, or various other things.. D’Adamo’s claim here is that his typing groups are a combination of gene inheritance and gene expression, and his notion of “strategies” isn’t really the same as say, having a completely different way of digesting foods.
It’s more like identifying which places to store fat in first—something that (IIUC) we already know is heritable. The fact that fat gets stored isn’t changed, just how much, where, and how quickly. Something like that can make a big difference on a practical level to a person’s life, without being a particularly complex adaptation in itself.