|Darwin Seminar: Dr. Richard Lewontin
|Event Date: 10.12.2009
Time: 12:00 noon
Location: Davis Auditorium, 4th Floor, Schapiro Center
Event Type: Special
Dr. Richard Lewontin
Population Genetics Department
Professor of Biology Emeritus,
Alexander Agassiz Professor of Zoology in the Museum of Comparative Zoology, Emeritus
Title: "Genes, Environment and the Phenotype"
A short abstract of the talk-
essence of the modern form of Darwinism is a separation of internal and
external forces. Genes determine organisms and natural selection of the most
fit types results in the adaptation of organisms to externally determined
niches. In reality, neither of these assertions true. First, the phenotypes of
organisms are a consequence of a very complex dependence of the development and
physiology of an organism on unique interactions between genes and environment
as well as random factors in development. Moreover the environment of one
genotype includes the frequency of various alternative genotypes in the
population. Thus, fitnesses are often frequency-dependent in complex ways.
Second, species do not "adapt" to environment in the sense of fitting
into preexistent "ecological niches". The niches are created by the
organism and evolve along with organisms. Thus, organisms actively
"construct" and modify their niches by their metabolic and sensory
functions, so as organisms evolve their niches evolve with them.
as there is no organism without a niche, there are no niches without organisms.
A realistic evolutionary theory must take into account the complex feedback
between organism and environment in the evolutionary process. In formal terms,
the equations of evolutionary change must be of the form of a pair of coupled
differential equations in which the change of organism is a function of both
organism and environment and the change of environment is also some function of
both organism and environment.
Host: Prof Walter Bock