Evolution- selection: week 4

• Fitness can be measured by reproductive success, which is the total number of offspring produced over its lifetime
• Natural selection occurs when there are differences in fitness between different genotypes or phenotypes within a population
• The fitness of an individual depends on both its genotype and environment
• The fitness of an individual is the number of offspring it produces relative to other individuals
• Genetic variation exists within populations due to mutation, sexual reproduction, migration, and gene flow
• Genetic correlation is when selection on 1 trait causes a change in an other trait
• acclimatization is a change in an individual phenotype that occurs in response to a change in natural environment conditions
• what are the modes for selection?

  directional, stabilizing, disruptive, balancing
• Directional selection favors one extreme of a population's range of phenotypes over others.
• Stabilising selection favours intermediate values of a character (phenotype) over extremes.
• Disruptive selection favours two or more different phenotypic classes at opposite ends of a distribution over those with intermediate phenotypes.
• evolution is a change in alleles frequencies in a population
• If the allele frequencies change what does that mean?

  that evolution has occur