Natural Selection 121that this may not be an issue which is resolvable by any sort of straightforward
epistemic means.
While Godfrey-Smith is right to see biologists such as Dawkins (and perhaps
philosophers such as Dennett) as defending explanatory adaptationism, it isn’t
clear that this thesis is a focus of the adaptationism debate. Amundson [1994] de-
velops a similar set of distinctions, except that he is more focused on the particular
criticism that adaptationists ignore the significance of developmental constraints.
According to Amundson, adaptationists tend to see developmental considerations
as a kind of constraint on adaptation. On this picture developmental constraints
are on a par with genetic constraints, random genetic drift, and any other factors
that “get in the way” of natural selection. If natural selection is powerful enough,
it will overcome these other factors and processes.
However, Amundson is concerned that we see the developmental challenge in
a more radical way. Developmental constraints are not processes that constrain
natural selection the way that drift, mutation, migration, and so on do since these
can all be represented in population genetics models along with selection to de-
termine the relative importance of these processes in the evolution of a particular
trait in a population. Drift is a theoretical option in the standard approaches
to population genetics; even when itssignificanceis denied, there is no problem
in understanding how it could make a difference in the models, at least theoret-
ically. Development, on the other hand, has been “black-boxed” and not as well
integrated. Amundson claims that many fans of developmental constraints see
something misguided about the traditional picture in which drift, selection and
development are all on a par. Drift and selection share a common vocabulary and
mathematical framework, but development does not.
Godfrey-Smith [2001] points to Dawkins’ [1982] claim that the neutralism de-
bate is orthogonal to the kind of adaptationism that he (Dawkins) wants to defend
as evidence that Dawkins is not an empirical adaptationist. According to Dawkins,
the adaptationism debate is concerned with non-molecular traits. He writes that
“given that we are dealing with a phenotypic effect big enough to see and ask
questions about, we should assume that it is the product of natural selection.” So,
according to Dawkins, the neutrality controversy is really a secondary issue.
While I agree that much of the adaptationism debate is orthogonal to the debate
about neutralism, I don’t think this sort of passage is sufficient evidence that
Dawkins is not (or perhaps not) an empirical adaptationist. The right sort of
attitude to take is to note that there are really two separate controversies here,
one about neutralism that is at the molecular level, and a largely distinct debate
about adaptations at the macroscopic level. Dawkins can still be viewed as an
empirical adaptationist because of his belief that due to the richness of variation
natural selection will tend to overcome pleiotropy and various sorts of genetic
constraints.
Like Godfrey-Smith [2001], Amundson [1994] points out that defenders of de-
velopmental constraints have a different view about what the primary explanan-
dum of evolutionary theory is. Standard neo-Darwinian biology views adaptations