A paradigm's worth of difference? Understanding the impasse over modern human origins

Abstract

The modern human origins debate within paleoanthropology has become polarized between two dominant models, Recent African Origin (RAO) and Multiregional Evolution (MRE). The debate has persisted and shows no sign of resolution despite the incorporation of new data and dates during the past decade. We examine the reasons for this stalemate, focusing on the presentation of these models by their principal advocates, Christopher Stringer and Milford Wolpoff. In particular, we consider whether the RAO-MRE dispute is a paradigm crisis. The modern human origins debate can be placed in the broader context of unresolved controversies within evolutionary biology (e.g., punctuated equilibrium vs. gradualism, use of cladistics, and species definitions). While the two sides hold conflicting views, we argue that such differences do not constitute a paradigm clash. Since both share a commitment to Darwinian evolutionary theory, the debate cannot be characterized as a paradigm clash at the level of, e.g., Ptolemaic vs. Copernican astronomy. Furthermore, we submit that a debate having historical roots reaching back into the previous century should not be portrayed as a conflict between competing paradigms in the Kuhnian sense. Preferences toward discontinuity or continuity wax and wane, persisting in a variety of scientific disciplines. We do not predict the quick demise of either MRE or RAO but are optimistic that careful evaluation of the characters and data on which claims about modern human origins are based will lead us toward a resolution of the current impasse. Yrbk Phys Anthropol 40:113–138, 1997. © 1997 Wiley-Liss, Inc.