Biomedical Engineering Reference
In-Depth Information
5
Genetic Engineering and Eugenics: The Uses
of History
Diane B. Paul
The prospect of human genetic engineering is inextricably entangled with
fears about eugenics. One reason for the intensity of the concern is that
genetic engineering techniques seem to overcome traditional limitations
on efforts to shape the course of human evolution. Past efforts to do so
essentially involved the application to humans of principles of plant
and animal breeding.
1
Practices such as segregation and sterilization of
“defectives,” immigration restriction, the Nazi murder of mental patients
and
Lebensborn
program, Fitter Families and Better Babies contests,
advocacy of “free love,” proposals for family allowances, dissemination
of birth control information and devices, and sperm banking were all
directed, in whole or part, at affecting who would become parents of the
next generation based on often dubious assumptions about the causal
connection between visible traits and underlying heredity. Even when
phenotypes were a good indication of genotypes, “positive eugenics”
(which aims to increase the frequency of favorable traits in a population)
depended on the uncertain cooperation of the subjects, and was limited
in its effects by the process of sexual reproduction, which means that
individuals transmit only half their genes. With respect to “negative
eugenics” (which aims to decrease the frequency of undesirable traits),
the reliance on phenotypes meant that policies could only reach those
who were obviously affected, leaving mostly untouched the large reser-
voir of invisible carriers. From this heterozygous reserve, a new affected
population would be created each generation. For all these (and other)
reasons, what geneticist John Maynard Smith has termed “selectionist
eugenics” is both slow and inefficient.
Genetic engineering, on the other hand, allows the isolation of specific
genes and their alteration in specific ways, and is therefore potentially
