How to rethink evolutionary theory: a plurality of evolutionary patterns.

"Nature" has recently depicted the empirical advancements of the theory of evolution as a confrontation between “reformists”, that claim for an urgent rethinking of the standard neo-Darwinian approach including so far neglected factors and processes, and “conservatives” whothat reply “all is well” about the current evolutionary research programme based on genetic variation and natural selection. The fight is mainly around genetic reductionism, but it seems inconclusive. Reformists stress very important factors, but they are still missing a coherent proposal about the architecture of the future extended evolutionary theory. Conservative react defensively, relying just on non-essential add-ons to the old and stable neo-Darwinian core. We analyze the debate and we propose an interpretation. Evolutionary biology is a rapidly expanding field. The bone of contention is how to update and extend the central core of the Darwinian legacy. We propose here the idea that what is happening in the field today is a development of the evolutionary research programme, whose structure is composed of a set of compatible and integrated evolutionary patterns. Evolutionary biology has been extended over its history by the inclusion of more and more patterns, rather than by revision to core theory. Niles Eldredge’s “Hierarchy Theory” is an example of global structure (meta-theory) aiming at incorporating and unifying the currently observed evolutionary patterns.