What does the dreaded "E" word mean, anyway

Natural History, Feb, 2000 by Stephen Jay Gould

This little fable can help us understand how peculiar and how contrary to all traditions of Western thought and explanation the Darwinian theory of evolution, and variational theories of historical change in general, must sound to the common ear. All the odd and fascinating properties of Darwinian evolution--the sensible and explainable but quite unpredictable nature of the outcome (dependent upon complex and contingent changes in local environments), the nonprogressive character of the alteration (adaptive only to these unpredictable local circumstances and not inevitably building a "better" elephant in any cosmic or general sense)--flow from the variational basis of natural selection.

Transformational theories work in a much simpler and more direct manner. If I want to go from A to B, I will have so much less conceptual (and actual) trouble if I can postulate a mechanism that will just push me there directly than if I must rely upon the selection of "a few good men" from a random cloud of variation about point A, then constitute a new generation around an average point one step closer to B, then generate a new cloud of random variation about this new point, then select "a few good men" once again from this new array--and then repeat this process over and over until I finally reach B.

When one adds the oddity of variational theories in general to our strong cultural and psychological resistance against their application to our own evolutionary origin (as an unpredictable and not necessary progressive little twig on life's luxuriant tree), then we can better understand why Darwin's revolution surpassed all other scientific discoveries in reformatory power and why so many people still fail to understand, and may even actively resist, its truly liberating content. (I must leave the issue of liberation for another time, but once we recognize that the specification of morals and the search for a meaning to our lives cannot be accomplished by scientific study in any case, then Darwin's variational mechanism will no longer seem threatening and may even become liberating in teaching us to look within ourselves for answers to these questions and to abandon a chimerical search for the purpose of our lives, and for the source of our ethical values, in the external workings of nature.)

These difficulties in grasping Darwin's great insight became exacerbated when our Victorian forebears made their unfortunate choice of a defining word--"evolution"--with its vernacular meaning of "directed unfolding." We would not face this additional problem today if "evolution" had undergone a complete transformation to become a strict and exclusive definition of biological change--with earlier and etymologically more appropriate usages then abandoned and forgotten. But important words rarely undergo such a clean switch of meaning, and "evolution" still maintains its original definition of "predictable unfolding" in several nonbiological disciplines-including astronomy.

When astronomers talk about the evolution of a star, they clearly do not have a variational theory like Darwin's in mind. Stars do not change through time because mama and papa stars generate broods of varying daughter stars, followed by the differential survival of daughters best adapted to their particular region of the cosmos. Rather, theories of stellar "evolution" could not be more relentlessly transformational in positing a definite and predictable sequence of changes unfolding as simple consequences of physical laws. (No biological process operates in exactly the same manner, but the life cycle of an organism certainly works better than the evolution of a species as a source of analogy.)