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Mutation Variation Natural Selection Speciation
Quick Review: Natural Selection
Organisms better suited to the environment
SURVIVE & REPRODUCEat a greater rate than those
less suited to the environment and this is how…
SPECIES EVOLVE
1. Macroevolution (Speciation):Changes which occur at or above the species
level
2. Microevolution (Population Genetics):Changes which occur within the species level
Studying Evolution
Microevolution is awesome!
Microevolution:A small scale shift in allele frequencies over
timeMechanisms for Microevolution:
1. Mutations/Recombination2. Genetic Drift3. Gene Flow4. Natural Selection
Microevolution
I still love math!
1. Mutations/RecombinationRarely impact plants and animals
1/100,000 genes98% of our DNA is junk (noncoding)Somatic cell mutations die with animal
Only Gamete mutations are inherited
1. Mutations/RecombinationOnce a mutation occurs, nearly all phenotypic
variations will result from shuffling of existing alleles
2. Genetic DriftChanges in the gene pool of a population
Typical Effect: decrease in genetic variationThe smaller the population, the greater the
effect