from: Daniel Dennett, Darwin’s Dangerous Idea, read May/June 1999

New discoveries may conceivably lead to dramatic, even “revolutionary” shifts in the Darwinian theory, but the hope that it will be “refuted” by some shattering breakthrough is about as reasonable as the hope that we will return to a geocentric vision and discard Copernicus.

The DNA in your body, unsnarled and linked, would stretch to the sun and back several – ten or a hundred – times. .... Biological macromolecules have a storage capacity that exceeds that of the best present-day information stores by several orders of magnitude.

Darwin explains a world of final causes and teleological laws with a principle that is, to be sure, mechanistic but – more fundamentally – utterly independent of “meaning” or “purpose”. It assumes a world that is absurd in the existentialist’s sense of the term: not ludicrous but pointless, and this assumption is a necessary condition of any non-question-begging account of purpose. Whether we can imagine a non-mechanistic but also non-question-begging principle for explaining design in the biological world is doubtful; it is tempting to see the commitment to non-question-begging accounts here as tantamount to a commitment to mechanistic materialism, but the priority of these commitments is clear…One argues: Darwin’s materialistic theory may not be the only non-question-begging theory of these matters, but it is one such theory, and the only one we have found, which is quite a good reason for espousing materialism.

In macroscopic biology – the biology of everyday-sized organisms such as ants and elephants and redwood trees – everything is untidy. Mutation and selection can usually only be indirectly and imperfectly inferred, thanks to a mind-boggling array of circumstantial complications. In the molecular world, mutation and selection events can be directly measured and manipulated, and the generation time for viruses is so short that huge Darwinian effects can be studied. For instance, it is the horrifying capacity of toxic viruses to mutate in deadly combat with modern medicine that spurs on and funds much of this research (the AIDS virus has undergone so much mutation in the last decade that its history over that period exhibits more genetic diversity – measured in codon revision – than is to be found in the entire history of primate evolution).

Nothing complicated enough to be really interesting could have an essence…contrary to what you might think, there is nothing natural about essentialist thinking; seeing the world through essentialist glasses does not at all make your life easy.

We want to draw lines; we often need to draw lines…Our perceptual systems are even genetically designed to force straddling candidates for perception into one classification or another, a Good Trick but not a forced move. Darwin shows us that evolution does not need what we need; the real world can get along just fine with the de facto divergences that emerge over time, leaving lots of emptiness between clusters of actuality.

An impersonal, unreflective, robotic, mindless little scrap of molecular machinery is the ultimate basis of all the agency, and hence meaning, and hence consciousness, in the universe.

The very considerations that in other parts of the biospere count for an explanation in terms of natural selection of an adaptation – manifest utility, obvious values, undeniable reasonableness of design – count against the need for any such explanation in the case of human behaviour. If a trick is that good, then it will be routinely rediscovered by every culture, without need of either genetic descent or cultural transmission of the particulars.