From: philjohn@garnet.berkeley.edu
Newsgroups: sci.bio
Subject: Gould versus Dawkins
Date: 2 Jan 93 06:32:21 GMT
Organization: University of California, Berkeley
NNTP-Posting-Host: garnet.berkeley.edu

Stephen Jay Gould's very negative review of Helena Cronin's book
"The Ant and the Peacock" appeared in the New York Review of
Books for Nov. 19, 1992.  Cronin is a follower of the "gene
selection" theory of Richard Dawkins, and so Dawkins is the real
target of Gould's ire.  Cronin and Dawkins are concerned to
explain complex adaptations, including behavior, on the basis of
the neo-Darwinian mechanism of random mutation and natural
selection.  Hence other kinds of evolution -- e.g., neutral
mutations at the molecular level that do not affect fitness --
are beside the point for them.  Similarly, whether occasional
examples of species selection occur is of little importance if
selection at the species level isn't responsible for creating
complex adaptive organs or behaviors such as altruism.  As
readers of Dawkins are aware, he believes that in adaptationist
evolution, natural selection operates by preserving genes or gene
combinations that produce characteristics that provide superior
fitness in the phenotypes.

Gould attacks this gene-focused approach as "bankrupt," in
language that raises questions about just how Gould himself would
account for the existence of those complex marvels of biology
that the natural theologians before Darwin attributed to the hand
of the Designer.  Here is the crucial passage from Gould's
review:

"...the replicator criterion is at best insufficient, and at
worst entirely mistaken.  A simple appeal to vernacular usage
tells us that a lower unit (a gene, for example) can't be an
exclusive agent if all the action occurs at higher levels
(organisms, for example) -- and the properties that generate this
action are 'emergent' characters of the higher level -- that is,
not a simple summation of features built by the lower units
(genes).  Now, manifestly (and gene selectionists do not deny
this) organisms are primary objects struggling for reproductive
success in nature.  How, then, can "hidden" genes be the true
agents if organisms are doing the fighting, cooperating,
generating, and dying?  Gene selectionists respond that all the
relevant properties of organisms can be described as results of
the various genes involved in their construction.  Such
properties, the argument continues, are therefore only the
complex manifestation of genetic action.
    But many, undoubtedly most, properties of organisms are not
simple summations of contributions from several genes.  They are
products of interactions among genes and therefore THEY CANNOT,
IN PRINCIPLE, BE ADEQUATELY PREDICTED OR KNOWN AT THE LEVEL OF
GENES.  Since selection acts on such emergent properties of
organisms, genes cannot be exclusive units of selection."
[Emphasis added]

     Does this passage make sense?  According to neo-Darwinism,
natural selection builds complexity by acting upon inheritable
characteristics, which is to say characteristics that are
traceable ultimately to some gene or combination of genes. 
Granted that the properties in question are products of
interactions among genes, one would still expect the combination
of genes that produced a particular property (e.g., incipient
wings or eyes) to have a predictable tendency (at least) to
interact again to reproduce the same property in the organism's
descendants.  Otherwise, how does a mutation conferring superior
fitness get passed on to succeeding generations?  And how does
Gould know that most properties of organisms cannot IN PRINCIPLE
be adequately predicted or known at the level of genes?

To put it another way, if Gould is right and Dawkins is wrong,
how did the bat get its wings and echolocation capabilities?