19. The (Diagrammatic) Narratives of Genetic Revolutions

Abstract

Chapter 19 looks at the ways in which the practitioners themselves conceive of the history of their field. The second revolution in ancient DNA research is said to have revealed that present-day genetic samples did not allow for the reconstruction of ancient events because, contrary to Luigi Luca Cavalli-Sforza’s and other pioneers’ expectations, people had migrated and mixed, thus blurring the genetic patterns of the past. Although such a view seems to deconstruct the tree diagram and the associated notion that living humans can be biologically grouped into primeval ‘races’ once and for all, some population geneticists and public figures maintain that meaningful average genetic differences between populations exist.