| HIGHLIGHTS | Key Terms | Key Concepts |
|---|---|---|
| 9.1 Darwin | evolution--p.171 | In 1831 Darwin began a trip around the world, closely observing the plants and animals he saw. |
| natural selection--p.171 | In 1859 Darwin published On the Origin of Species, in which he proposed that the mechanism of evolution was natural selection. | |
| Galapagos Islands--p.172 | ||
| On the Origin of Species--p.174 | ||
| 9.2 The Evidence for Evolution | fossil--p.175 | If we date fossils, and order them by age, progressive changes are seen. This is direct evidence that evolution has occurred. |
| radioisotopic dating--p.175 | The progressive accumulation of molecular differences and comparisons of living organisms provide additional strong evidence that evolution has occurred. | |
| molecular clock--p.178 | ||
| homologous structure--p.180 | ||
| 9.3 How Populations Evolve | microevolution--p.182 | In a population not undergoing significant evolutionary change, two alleles present in frequencies p and q will be distributed among the genotypes in the proportions p2 + 2pq + q2 the Hardy-Weinberg equilibrium. |
| allele frequency--p.182 | Allele frequencies change in nature due to mutation, migration, drift, nonrandom mating, and selection. | |
| Hardy-Weinberg equilibrium--p.182 | ||
| directional selection--p.187 | ||
| balancing selection--p.187 | ||
| 9.4 Adaptation: Evolution in Action | sickle-cell anemia--p.188 | A mutation in hemoglobin causes a condition known as sickle-cell anemia. This recessive mutation is common in central Africa because it renders heterozygous individuals resistant to malaria. |
| industrial melanism--p.190 | Vegetation darkened by industrial soot has favored the evolution of darker moths, better concealed from their predators. | |
| 9.5 How Species Form | species--p.192 | Microevolution leads to macroevolution. Adaptation to local habitats leads to divergence and the evolution of ecological races. |
| ecological race--p.193 | Isolating mechanisms then reinforce the differences, leading to reproductive isolation and species formation. | |
| isolating mechanism--p.194 | ||
| punctuated equilibrium--p.196 |