Several times Ian has referred to his advocacy of Developmental Systems
Theory as the basis for generation of complex traits that might be
susceptible to selection. This set of concepts, originally articulated by
Susan Oyama, a psychologist, along with other psychologists like Gilbert
Gottlieb, has made an important contribution to evolutionary developmental
biology, precisely because it shows how the environment collaborates with
the genes to produce phenotypic characters, even in such presumably
"hard-wired" aspects as morphology. (See, for example, Robert, J. S., Hall,
B. K. and Olson, W. M. (2001). Bridging the gap between developmental
systems theory and evolutionary developmental biology. Bioessays 23,
954-62). If body morphology is not as independent of the environment as
conventionally thought, certainly psychological attributes are even less so.
Thus DST is very different in spirit from the evolutionary psychology
purveyed by Pinker et al., who are always talking about presumed genetic
determination of cognitive characters, usually in the complete absence of
evidence. Indeed, the recent edition of Oyama's "The Ontogeny of
Information" has a foreword by Richard Lewontin!
The idea that epigenetic, potentially reversible, mechanisms play, and
during evolution, have played, a greater role in the determination and
origination of biological characters than proposed by neo-Darwinism is
gaining increasing hold even among those scientists who actually study
specific genetic contributions to complex traits. Thus evolutionary
developmental biology is moving away from neo-Darwinism; attempts to push
psychology further in that direction is thus doubly reactionary. A volume
edited by Gerd Muller and myself with contributions by cellular,
developmental, and evolutionary biologists, that presents detailed examples
of this approach will be published in January (Müller, G. B. and Newman, S.
A. 2003. Origination of organismal form: beyond the gene in developmental
and evolutionary biology, Cambridge, MA: MIT Press).
Stuart A. Newman, Ph.D.
Department of Cell Biology and Anatomy
Basic Science Building
New York Medical College
Valhalla, NY 10595
Tel: (914) 594-4048
Fax: (914) 594-4653
E-mail: [log in to unmask]
From: Ian Pitchford [mailto:[log in to unmask]]
Sent: Monday, November 04, 2002 8:20 PM
To: [log in to unmask]
Subject: Re: Genes and traits
Stuart Newman wrote:
Perhaps my comments were off-target? I was reacting to articles and
commentaries like the following: Balter M. Language evolution. 'Speech gene'
tied to modern humans. Science 2002 297:1105, and Savulescu J. Procreative
beneficence: why we should select the best children. Bioethics 2001
15:413-26. I recognize that such things are not published in Human Nature
Review, but they are certainly part of the field known as evolutionary
psychology. Indeed, In searching through articles listed on the Human
Nature Review website I almost never encountered the words "genetics" or
"genes." (An exception is a review of a book on Human Evolutionary
Psychology where the only uses of these terms are in relation to the book's
background materials on the theory of evolution).
REPLY: You concentrate on genes rather than the integrative approach based
Tinbergen's four questions (proximal, developmental, functional, and
evolutionary) and rooted in Oyama's developmental systems theory that I
advocated. Language is certainly a good candidate for an adaptation for all
the reasons that Pinker and Bloom give in their well-known BBS paper
Language and Natural Selection":
"All human societies have language. As far as we know they always did;
was not invented by some groups and spread to others like agriculture or the
alphabet. All languages are complex computational systems employing the same
basic kinds of rules and representations, with no notable correlation with
technological progress: the grammars of industrial societies are no more
complex than the grammars of hunter-gatherers; Modern English is not an
over Old English. Within societies, individual humans are proficient
users regardless of intelligence, social status, or level of education.
Children are fluent speakers of complex grammatical sentences by the age of
three, without benefit of formal instruction. They are capable of inventing
languages that are more systematic than those they hear, showing
to languages that they have never heard, and they obey subtle grammatical
principles for which there is no evidence in their environments. Disease or
injury can make people linguistic savants while severely retarded, or
linguistically impaired with normal intelligence. Some language disorders
genetically transmitted. Aspects of language skill can be linked to
characteristic regions of the human brain. The human vocal tract is tailored
the demands of speech, compromising other functions such as breathing and
swallowing. Human auditory perception shows complementary specializations
toward the demands of decoding speech sounds into linguistic segments.
This list of facts (see Pinker, 1989a) suggests that the ability to use a
natural language belongs more to the study of human biology than human
it is a topic like echolocation in bats or stereopsis in monkeys, not like
writing or the wheel. All modern students of language agree that at least
aspects of language are due to species-specific, task-specific biological
abilities, though of course there are radical disagreements about
Pinker, S., & Bloom, P. (1990). Natural language and natural selection.
Behavioral & Brain Sciences, 13(4), 707-784.
It wouldn't be in keeping with developmental systems theory to evaluate the
hypothesis that language is an adaptation purely through a reductionist
approach centred on genes.
Chomsky and others have pointed out repeatedly that connectionist approaches
(based on simple rules of learning and a domain-general architecture) have
failed to produce realistic models of language. On the basis of the
we have at present I believe it's reasonable to conclude (tentatively, of
course) that language is an adaptation. This is good science, whatever you
to call it.
Ian Pitchford PhD CBiol MIBiol
The Human Nature Review
Department of Psychiatry
Creighton University School of Medicine
3528 Dodge Street
Omaha, NE 68131, USA