| A | B |
|---|
| Genotype | Set of genes (alleles) an organism carries |
| Phenotype | All physical, physiological, and behavioral characteristics of an organism |
| Gene Pool | consists of all the genes that are present in a population |
| Allele Frequency | The number of times an allele occurs in the gene pool |
| For population to evolve, allele frequency must | change |
| Single-gene Traits | a trait controlled by only 1 gene, has 2 alleles and 2 phenotypes |
| Polygenic Traits | traits that are controlled by 2 or more genes, give a range of phenotypes |
| Example of single-gene trait | hitchhiker's thumb, widow's peak, 2nd toe longer than first |
| Example of polygenic traits | hair color, eye color, height, body mass, skin tone |
| Natural Selection | determines if the frequency of a mutation will increase in a population |
| Directional Selection | when individuals at one end of a polygenic trait curve have higher fitness than others |
| Stabilizing Selection | when individuals at the center of a polygenic trait curve have higher fitness than others |
| Disruptive Selection | when individuals at the outer ends of a curve have higher fitness than the center |
| Genetic Drift | When individuals in a population by chance produce more offspring |
| The Bottleneck Effect | The change in allele frequency after a dramatic event that reduces the population |
| The Founder Effect | When a small subgroup of a population leaves but has different allele frequencies than the original |
| Genetic Equilibrium | When a population doesn't evolve and allele frequencies don't change |
| Hardy-Weinberg Principle | Says that population should remain in genetic equilibrium unless 1 of 5 things happen |
| 5 fingers of evolution | small population size, nonrandom mating, mutation, movement in or out, natural selection |
| Speciation | the formation of a new species; 2 organisms cannot breed and produce fertile offspring |
| Behavioral Isolation | 2 populations develop differences in courtship rituals (ex: different bird songs) |
| Geographic Isolation | When 2 populations are separated by geographic barriers such as lakes, rivers, or mountains |
| Temporal Isolation | When 2 or more species reproduce at different times |
