chapter  3
34 Pages

DEVELOPMENTAL SYSTEMS

In the previous chapter I tried to show how the standard genetic assumptions underlying the current framework of nature-nurture debates in psychology are unlikely to be valid. This conclusion was reached simply from a brief consideration of genomic regulations, which appear to have evolved to deal with environmental perturbations that could easily throw direct expression from genes to characters ‘off track’. These appear to work by, as it were, ‘opening up’ structural gene expression in a more responsive and flexible deployment. The enormous significance of this arrangement is highlighted by the fact that up to 90 per cent of genes, and 95 per cent of the DNA associated with any particular gene, even in fruitflies, may be regulatory in function.