-------- Original Message -------- Subject: Re: Genes and traits Date: Thu, 07 Nov 2002 12:24:43 -0500 From: NEWMAN STUART <NEWMAN at NYMC.EDU> Reply-To: Science for the People Discussion List<SCIENCE-FOR-THE-PEOPLE at LIST.UVM.EDU> To: SCIENCE-FOR-THE-PEOPLE at LIST.UVM.EDU
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 Newman
*********************************************** 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: newman at nymc.edu Web: http://www.nymc.edu/sanewman
-----Original Message----- From: Ian Pitchford [mailto:ian.pitchford at SCIENTIST.COM] Sent: Monday, November 04, 2002 8:20 PM To: SCIENCE-FOR-THE-PEOPLE at LIST.UVM.EDU 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 on 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 of the reasons that Pinker and Bloom give in their well-known BBS paper "Natural Language and Natural Selection":
"All human societies have language. As far as we know they always did; language 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 advance over Old English. Within societies, individual humans are proficient language 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 resemblances 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 are genetically transmitted. Aspects of language skill can be linked to characteristic regions of the human brain. The human vocal tract is tailored to 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 culture; 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 some aspects of language are due to species-specific, task-specific biological abilities, though of course there are radical disagreements about specifics."
see: http://www.bbsonline.org/documents/a/00/00/04/99/bbs00000499-00/bbs.pinker.html
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 information 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 want to call it.
Regards
Ian Pitchford PhD CBiol MIBiol The Human Nature Review http://human-nature.com/
Department of Psychiatry Creighton University School of Medicine 3528 Dodge Street Omaha, NE 68131, USA
Tel: 402.345.8828 Fax: 402.345.8815 http://medicine.creighton.edu/psych/