100 likes | 545 Views
15.2 PDQ. 1. Name and define 3 processes that affect the genetic makeup of populations over time. Gene flow – exchange of genes between populations due to migration Genetic Drift – change in gene frequencies from generation to generation due to random processes
E N D
1. Name and define 3 processes that affect the genetic makeup of populations over time • Gene flow – exchange of genes between populations due to migration • Genetic Drift – change in gene frequencies from generation to generation due to random processes • Non-random mating – selection of mates on basis of traits • Mutation – change in DNA • Selection – choosing preferential phenotypes
2. Explain, “natural selection acts on individuals, but populations evolve” • Changes that occur are developmental in a single organism over the course of a life cycle. • After breeding populations will evolve
4. What is the difference between natural selection and adaptation? Natural Selection Adaptation Enhances the fitness of the organism • Difference in fitness among organisms
5. What is the raw material on which mechanisms of evolution act upon? • variation
6. What does it mean to say a population evolves? • It genetically changes over time
7. Why is genetic drift more apparent in small populations? • Because each individual’s genes represent a large fraction of the gene pool
8. What is the net affect of a population bottleneck? • Loss of genetic variation
9. Describe founder’s effect • Loss of genetic variation that occurs when a new population is established
10.Define sexual selection • Preference by 1 sex for certain characteristics