Methods and Problems in Physiological Genetics

The experimental requirements for seeking and quantifying genetic components in physiological variation may be complex, and other contributors have shown the difficulty of identifying such components in almost all the variables so far discussed. This is partly due to the nature of the variables themselves, characterized by lability and relative rapidity of response, but also may be partly due to the extent to which these investigations have relied on twin analysis, which taken alone poses considerable interpretative difficulty. But population genetics has devised other methods by which such estimates can be made, and these and the problems that arise in them can be illustrated by some of our own studies in the Newcastle Human Genetics Department on physiological variables. But first some general theoretical comments on the genetic basis of physiological variation.