Darwin's Finches or Lamarck's Giraffe, Does International Relations Get Evolution Wrong?

Following the recent 150th anniversary of the publication of The Origin of Species, we are in the midst of a surge of Darwinian models of social change in international relations and even genetic and sociobiological analyses of politics more generally. But does being correct biologically make the Darwin/Mendel synthesis an appropriate model of change in world politics? This is an open question and one made interesting by the existence of multiple discarded models of biological evolution, most prominent among them being Lamarck's model of inheritance of acquired characteristics. So we can also ask, conversely, does being incorrect biologically disqualify a model for use in international relations? In this article, we explore this question by examining the challenges of evolutionary analysis and analyzing Lamarckian evolution side by side with Darwinian evolution. If IR is to pursue evolutionary analysis, we argue that Lamarck deserves a second look.