A developmentalist’s view of inheritance

Recent years have witnessed the emergence of extensive new data suggesting a different view of inheritance from the view that has dominated biology for over a century. It suggests that what is transmitted across generations are the developmental means to construct phenotypes predicted to match anticipated environmental conditions. Those ‘developmental means’ include genes, but also other resources that parents bequeath to descendants, as well as activities parents engage in to construct the environmental context in which their offspring develop. If there are similarities between the traits of parents and offspring it is because, within lineages, phenotypes are reliably re-constructed across generations. Extra-genetic inheritance processes do an important job in evolution, but that job is, in the main, distinct from that of genetic inheritance. They are best regarded – not as noise, fine-tuning or baroque “add ons” (Wray et al. 2014) – but as essential tools for short-term, rapid-response adaptation. The true function of heredity is to make an informed forecast.