What is the difference between directional selection and stabilizing selection?
Directional selection leads to an increase or decrease in allele frequency depending on whether an allele is favored or selected against in a particular environment. The result is a linear change in allele frequency that tends to reduce gene diversity in a selected population. Stabilizing selection removes from a population phenotypes that deviate in either direction from the optimum value for a character. If the optimum phenotype results from additive or other interactions (such as overdominance) among several loci, the result is to maintain genetic diversity in a selected population. 3. Define pathogen fitness. Name as many fitness parameters as you can imagine for a pathogen in an agricultural ecosystem. Fitness is an especially complicated concept for pathogens. Fitness is often based on the total output of viable progeny by an individual in its lifetime. But pathogen fitness must also take into account transmissiveness of the progeny because a pathogen that does not propagate by i
