Paleoanthropology: Science or mythological charter?

Causal explanations involve both narrative and laws. To explain some event as the effect of other events, we must at least demonstrate (1) that the cause and effect both took place, with the cause preceding the effect, and (2) that the effect belongs to a class of events that can be reliably expected to follow from a class of events to which the cause belongs. Demonstration (1) is a narrative; demonstration (2) is a law. Narrative and "contingency" are not satisfactory substitutes for laws in explaining evolutionary events. If any evolutionary events are explicable, there must be evolutionary laws, and the course of evolution must therefore be to some extent predictable. However, many evolutionary events will probably always elude causal explanation. In particular, as Hume pointed out, qualitatively unique events cannot be explained causally. If human beings possess qualitatively unique traits, their causes must remain a subject for speculation. The only evolutionary events we can explain, in our own lineage or any other, are those that conform to recurring regularities.