1. EVOLUTION DAY REVIEW

2. DARWIN’S FOUR CRITERIA FOR NATURAL SELECTION TO OCCUR Overproduction of offspring leads to more offspring than environment can support Variation in those offspring Variations are inherited Offspring that are better adapted to environment leave subsequently more offspring

3. Darwin also saw that when humans choose organisms with specific characteristics as breeding stock, they are performing the role of the environment –This is called artificial selection Figure 13.4A Adopt me!!

4. The evolution of insecticide resistance is an example of natural selection in action Figure 13.5B Chromosome with gene conferring resistance to insecticide Additional applications of the same insecticide will be less effective, and the frequency of resistant insects in the population will grow Survivor Insecticide application

5. A species is a group of populations whose individuals can interbreed and produce fertile offspring A population is a group of interbreeding individuals living in same place and same time. Populations evolve, not individuals!!! 13.6 POPULATIONS ARE THE UNITS OF EVOLUTION Figure 13.6

6. A gene pool is the total collection of genes in a population at any one time Microevolution is a change in the relative frequencies of alleles in a gene pool 13.7 MICROEVOLUTION IS CHANGE IN A POPULATION’S GENE POOL OVER TIME

7. Hardy-Weinberg equilibrium states that the shuffling of genes during sexual reproduction does not alter the proportions of different alleles in a gene pool In other words, when the population is in Hardy Weinberg equilibrium, the population in NOT EVOLVING!!!! We often can use HW to estimate allele frequencies in human populations! 13.8 THE GENE POOL OF A NONEVOLVING POPULATION REMAINS CONSTANT OVER THE GENERATIONS Figure 13.8A

8. The population is very large (no genetic drift) The population is isolated (no emmigration or immigration) Mutations do not alter the gene pool (no mutations) Mating is random(no selective mating) All individuals are equal in reproductive success (no natural selection) 13.10 FIVE CONDITIONS ARE REQUIRED FOR HARDY- WEINBERG EQUILIBRIUM

9. FIVE FINGERS OF EVOLUTION (CAUSES OF MICROEVOLUTION) Small population size and Genetic Drift Non-random mating Mutations Gene flow (migration) Natural selection

10. An individual’s fitness is the contribution it makes to the gene pool of the next generation relative to the contribution made by other individuals Production of fertile offspring is the only score that counts in natural selection 13.18 GENES PUT INTO FUTURE GENERATIONS DEFINE EVOLUTIONARY FITNESS

11. 13.19 THERE ARE THREE GENERAL OUTCOMES OF NATURAL SELECTION Figure 13.19 Frequency of individuals Original population Phenotypes (fur color) Original population Evolved population Stabilizing selectionDirectional selectionDiversifying selection

12. The biological species concept defines a species as –a population or group of populations whose members can interbreed and produce fertile offspring

13. The biological species concept is not to asexual organisms Most organisms are classified based on observable phenotypes –The morphological species concept The genealogical species concept defines a species as a cluster of organisms representing a specific evolutionary lineage The ecological species concept defines a species by its ecological role

14. Hybrid sterility is one type of postzygotic barrier –A horse and a donkey may produce a hybrid offspring, a mule –Mules are sterile Figure 14.2C

15. When a population is cut off from its parent stock, species evolution may occur An isolated population may become genetically unique as its gene pool is changed by natural selection, genetic drift, or mutation This is called allopatric speciation 14.3 GEOGRAPHIC ISOLATION CAN LEAD TO SPECIATION MECHANISMS OF SPECIATION Figure 14.3

16. Adaptive radiation on an island chain Figure 14.4B Species A from mainland 1 A 2 B B 3 B C 4 C C 5 B C D C D

17. ADAPTIVE RADIATION OF DINOSAURS