1. More Evolution notes…

2. Darwin’s Theory of Evolution
Species change and evolve over time due to the processes of natural selection and genetic variation

3. Populations evolve
Gene pool: all of the alleles of a population’s genes
Allelic Frequency: % of an allele in the gene pool

4. Genetic Equilibrium
Genetic Equilibrium: a population in which the frequency of alleles remains the same
Genetic Equilibrium can be disrupted by:
Mutations: can result in a useful variation
Genetic drift: the change of allelic frequencies caused by chance events
Gene flow: the addition or subtraction of genes of a gene pool

5. Speciation Speciation: the evolution of a new species
Speciation can occur by:
Geographic isolation: when a physical barrier separates a population
Reproductive isolation: when members of a population can no longer mate and produce fertile offspring
Polyploidy: organism that contains a multiple of the normal set of chromosomes

6. Speciation Speciation can occur by (cont.):
Gradualism: the idea that species originate through a gradual change in adaptations
Punctuated equilibrium: speciation occurs relatively quickly and in rapid bursts

7. Emergence of new species
Divergent evolution: when species that were once similar to an ancestral species diverge
Adaptive radiation: when an ancestral species evolves into an array of species to fit a number of different habitats
Convergent evolution: when distantly related organisms evolve similar traits

8. Types of Natural Selection
Directional selection: natural selection that favors one of the extreme variations of a trait
Stabilizing selection: natural selection that favors the average individuals in a population
Disruptive selection: natural selection that favors either extreme of a trait’s variation

9. Aka: Disruptive

10. What type of evolution? Whale Sharks eat plankton with gills
Baleen Whales eat plankton with baleen

11. What type of Evolution Sharks have cartilagenous skeletons
Whales have bony skeletons