The answer to the question “what proportion of phenotypic variability is due to genetic variability?” always has the same answer: “it depends!” What population of environments are you doing this calculation over? A trait can go from close to 0% heritable to close to 100% heritable, depending on the range of environments in the sample. That’s a definition problem. Further, what should we count as ‘genetic’? Gene expression can depend on the environment of the parents, for example (DNA methylation, etc). That’s an environmental inheritance. I just think there is an old way of talking about these things that needs to go away in light of current knowledge.
I agree with you that we still can learn a lot from these studies.
The definition of ‘heritable’ being underspecified (since you have to specify what population of environments you’re considering) is not the same as being incoherent.
The answer to the question “what proportion of phenotypic variability is due to genetic variability?” always has the same answer: “it depends!” What population of environments are you doing this calculation over? A trait can go from close to 0% heritable to close to 100% heritable, depending on the range of environments in the sample. That’s a definition problem. Further, what should we count as ‘genetic’? Gene expression can depend on the environment of the parents, for example (DNA methylation, etc). That’s an environmental inheritance. I just think there is an old way of talking about these things that needs to go away in light of current knowledge.
I agree with you that we still can learn a lot from these studies.
The definition of ‘heritable’ being underspecified (since you have to specify what population of environments you’re considering) is not the same as being incoherent.
I agree. Good point.