BIOL 304 Lecture Notes - Lecture 6: Richard Goldschmidt, Clergy Letter Project, Mutationism
Document Summary
Genetic changes that are inevitable, and not always appropriately directed. Some part of the genome is more prone to mutation, some external factors- radiation-also affect mutation rate (mitochondria genome has more mutation) Richard goldschmidt "hopeful monster": theory that speciation is not accumulation of micromutations, but a result of macromutation (it is rejected afterwards) The yeast experiment: each strain has exactly one deletion of a gene. In rich medium, some deletions are lethal, most has no effect on growth rate. Selection inevitable consequence of variation in fitness (relative fitness) Population tend to exponential increase, limited resources leads to reproduction competition (resources increases at best linearly) Individuals vary in ability of obtaining resources and compete with others. Fitness must be inheritable fitness, the population with favorable trait will become predominant, and eventually lead to permanent change in genetic composition of the population: cause of evolution. Rapid changes in selection (e. g. harvesting and fish population, antibiotics and bacterial population)
