Species as Individuals in the Hierarchical Theory of Selection 711
evolution because such a process can't construct an intricate organismal phenotype
of numerous, developmentally correlated traits.
Dawkins (1982, pp. 106-108), for example, damns species selection with faint
praise in these terms:
I shall argue that a belief in the power of species selection to shape simple
major trends is not the same as a belief in its power to put together complex
adaptations such as eyes and brains ... The species selectionist may retreat
and invoke ordinary low level natural selection to weed out ill-coadapted
combinations of change, so that speciation events only serve up already
tried and proved combinations to the sieve of species selection. But this
"species selectionist" ... has conceded that all the interesting evolutionary
change results from inter-allele selection and not from interspecies
selection, albeit it may be concentrated in brief bursts punctuating stasis ...
The theory of species selection ... is a stimulating idea which may well
explain some single dimensions of quantitative change in macroevolution. I
would be very surprised if it could be used to explain the sort of complex
multidimensional adaptation that I find so interesting.This statement commits the classic intentional fallacy of the prosecutor:
attributing beliefs not held to adversaries, and then castigating them for apostasy
(or praising them for good sense in recantation)—as illustrated by the paradigm for
an opening thrust in a line of inquiry: "when did you stop beating your wife?"
Dawkins finds the adaptive complexity of organisms uniquely interesting. I also
regard the subject as fascinating, and I would never attribute this quintessential
property of organisms to selection at some other level. I fully acknowledge, as do
all species selectionists, that the adaptive complexity of organisms arises primarily
by causal processes operating at the organismic level.
But this pluralistic principle applies equally well to other levels. If adaptive
complexity marks "what organisms do," and must therefore be explained at the
organismic level—then "what species do" implies a consideration of causation at
the species level. Species "do" two primary things in macroevolution: they carry
trends within clades across long geological stretches of time, and they stand as
basic units (geological "atoms" if you will) for counting the waxing and waning of
differential diversity through time (why does our current biota feature 500,000
named species of beetles, but fewer than 50 of priapulids?). As a paleontologist, I
regard these two phenomena as surpassingly important, while I remain happy to
grant Dawkins's commanding interest in the adaptive complexity of organisms. But
just as I try not to impose my causes (for other scales and levels) upon his material
a priori, I ask him to acknowledge the importance of my favored themes within a
comprehensive evolutionary theory (even if they do not engage his personal
concern), and therefore to recognize the efficacy of different appropriate causes at
this paleontological level. In short, Dawkins and others commit a classic
psychological