title: The Wilhelmine E. Key 1986 invitational lecture. Fifty years of genetic load.
abstract: The author's involvement with and his successive reactions to the genetic load concept [whose beginning is identified with Haldane's paper. The effect of variation on fitness] is presented in the form of a personal odyssey. The major change in attitude involved the realization that the density- and frequency-independent selection discussed by most population geneticists has little bearing on events transpiring within natural populations; instead, natural selection should be viewed primarily as a density- and frequency-dependent phenomenon. Under this view, the culling of a large number of young zygotes to the considerably smaller number of adults that can be sustained by the environment is an essential process enabling any population's continued existence; to the extent that genetic variation facilitates culling, a genetic load (in direct opposition to the early view) can enhance a population's persistence through time.
mesh_terms: D000818:Animals; D004331:Drosophila melanogaster / Q000235:genetics / Q000528:radiation effects; D014644:Genetic Variation; D005828:Genetics, Population; D005838:Genotype; D049673:History, 20th Century; D006801:Humans; D008957:Models, Genetic / Q000266:history*; D009154:Mutation; D011110:Polymorphism, Genetic; D011156:Population Density; D012641:Selection, Genetic; D014481:United States