This essay addresses two questions. It first asks what happens to security practices when they take species life as their referent object. It then asks what happens to security practices which take species life as their referent object when the very understanding of species life undergoes transformation and change. In the process of addressing these two questions the essay provides an exegesis of Michel Foucault’s analytic of biopolitics as a dispositif de sécurité and contrasts this account of security with that given by traditional geopolitical security discourses. The essay also theorises beyond Foucault when it interrogates the impact in the twentieth century of the compression of morbidity on populations and the molecular revolution on what we now understand life to be. It concludes that ‘population’, which was the empirical referent of early biopolitics, is being superseded by ‘heterogenesis’. This serves as the empirical referent for the recombinant biopolitics of security in the molecular age.