1. Recombination, Mutation, Genetic Drift, Gene Flow Also evolution Also evolution

2. Recombination  Remember Meiosis? This is when recombination occurs This is when recombination occurs Shuffling of chromosomes/genes/alleles Shuffling of chromosomes/genes/alleles Also crossing over Also crossing over  Remember fertilization? Coming together of shuffled genes Coming together of shuffled genes  New alleles not created, just rearranged for more genetic variability rearranged for more genetic variability

3. Mutations  Creates new alleles  Beneficial, neutral, or lethal  Passed on to new generations if they arise in gametes  Can reduce chances of survival and reproduction

4.  If it causes severe reductions, usually ends with death  Neutral mutation changes base sequence but has no effect on survival or reproduction  Beneficial mutation ex. – corn plant has a mutation that makes it grow faster or larger giving it best access to sunlight and nutrients  Neutral mutation might prove helpful if the environment changes

5. Genetic Drift  Random changes in allele frequencies over time  Effect is greatest in small populations – leads to loss of genetic diversity Allele will become more or less prevalent in small pops Allele will become more or less prevalent in small pops  Bottleneck  and Founder Effect

6. Bottleneck  Drastic reduction in population size because of severe pressure

7. Founder Effect  A few individuals establish a new population  Unpredictable genetic shifts occur

8. Gene Flow  Physical movement of alleles into and out of a population  Opposes the effects of mutation, natural selection, and genetic drift  Keeps populations similar to one another  Increases genetic variability in that new population

9. Cladograms  Aka. Phylogenetic tree, branching tree, evolutionary tree  Lines not still apparent at present are extinct  Do not have to all face the same way

13. Hardy-Weinberg Principle 1. Random mating 2. Large population 3. No movement 4. No mutations 5. No natural selection  Allele frequency in a population will remain constant

14. H-W Principle  p 2 + 2pq + q 2 = 1  p + q = 1 p2 = frequency of homozygous dominant 2pq = frequency of heterozygous q2 = frequency of homozygous recessive p = dominant allele q = recessive allele

15. 1 in 1700 US Caucasian newborns have cystic fibrosis. C for normal is dominant over c for cystic fibrosis.  What percent of the above population have cystic fibrosis (cc or q 2 )?  What percent of the population do not have cystic fibrosis and are homozygous dominant (CC or p 2 )?  What percent of the population is heterozygous? H-W Principle