Darwin Seminar: Dr. Richard Lewontin

Event Date: 10.12.2009 Day: Monday Time: 12:00 noon Location: Davis Auditorium, 4th Floor, Schapiro Center Event Type: Special

A short abstract of the talk-

The 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.

Just 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.