Download
15 2 pdq n.
Skip this Video
Loading SlideShow in 5 Seconds..
15.2 PDQ PowerPoint Presentation

15.2 PDQ

425 Vues Download Presentation
Télécharger la présentation

15.2 PDQ

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. 15.2 PDQ

  2. 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

  3. 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. 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. 5. What is the raw material on which mechanisms of evolution act upon? • variation

  6. 6. What does it mean to say a population evolves? • It genetically changes over time

  7. 7. Why is genetic drift more apparent in small populations? • Because each individual’s genes represent a large fraction of the gene pool

  8. 8. What is the net affect of a population bottleneck? • Loss of genetic variation

  9. 9. Describe founder’s effect • Loss of genetic variation that occurs when a new population is established

  10. 10.Define sexual selection • Preference by 1 sex for certain characteristics