A lecture in two parts:
Firstly an account of the unhappy marriage between genetics and eugenics and their close kin with evolutionary theory in the 20th Century, an era in which eugenics turns from ideas into widespread public policy.
Secondly, an investigation of the central concept of the gene. By retracing the history of the gene from 1860 to 1960, it will be shown that, far from being a fixed category, what is meant by biologists when they speak of genes has changed over time and how the models of the geneticists have interacted with eugenics.