The hierarchical interplay between ecology and genealogy is a fundamental ingredient for the most compelling current explanations in evolutionary biology. Yet philosophy of biology has hardly welcomed a classic fundamental intuition by palaeontologist Niles Eldredge, i.e. the non-coincidence and interrelation between ecology and genealogy, and their interaction in a Sloshing Bucket fashion. Hierarchy Theory and the Sloshing Bucket need to be made precise, developed and updated in light of an explosion of new discoveries and fields and philosophical issues. They also suggests re-thinking concepts such as natural selection, species, and speciation that have always been part of evolutionary theory.
When philosophers, theorists, and working scientists think about evolution, they often do so by means of models based on inheritance. Natural selection, for example, is quantified as selective pressures, intended as coefficients directly influencing reproductive outputs, or summaries of the influences on reproductive outputs. Ecology therein is often seen as the circumstancy of evolution, a source of perturbations and influences which is accurately reflected, translated into units of reproductive output. Yet contemporary explanatory models of biological evolution, for example those that are emerging for Homo sapiens, show that a much much better understanding of the constructive interaction between two independent domains – the ecological and the genealogical – is required not only to account for quintessentially macroevolutionary events such as mass extinctions, but also for smaller-scale happenings such as speciations and intra-specific evolutionary innovations. The huge frequency of utterly inheritance-centric philosophical works on natural selection seems, in this light, an unmistakable symptom of theoretical inertia. Bucket Thinking could reflect the way in which the best evolutionary explanations are built today, and at the same time aid the explanation by laying down and relating the researches that are being conducted in different fields (e.g. from population genetics to palaeontology, from ecosystem ecology to developmental biology). Bucket Thinking is also a way of reframing many classical problems, such as multi-level selection, individuality, or even reductionism or emergence. This doesn’t mean that Hierarchy and the Bucket are free of their own epistemological and methodological problems. On the contrary, what we suggest is precisely a critical philosophical discussion more deep than the one that has been deserved until now to these potentially fruitful ideas. Hierarchy Theory asks to be developed and updated in light of an explosion of new discoveries and fields, e.g., EvoDevo, lateral gene transfer and the charge of zoo-centrism pending on evolutionary theory (O’Malley 2010), network theory, genomics. But the dual Hierarchy Theory is also a way of re-thinking and re-framing concepts that have ever been present in evolutionary theory, like natural selection itself, or species and speciation, as we have seen here.
Look for it in the Publications page (with additional links):
Pievani T, Serrelli E (2013). Bucket thinking: the future framework for evolutionary explanation. Contrastes. Revista internacional de filosofia – Suplementos 18: 389-405. ISSN 1139-9922 [http://hdl.handle.net/10281/44944]