- The primary cause of evolution
Based on 4 observations:
- Individuals w/in populations vary
- More than just color (physical traits)
- Drug resistance
- Blooming time in flowers
- Individual’s variation can be passed on
- Darwin noticed that animal breeders could get exaggerated traits through selective breeding.
- Populations produce more offspring than will survive
- Even slow-breeding animals can produce large populations relatively quickly.
- Survival and reproduction are not random
- Fitness: Relative survival and reproduction of one variant
- Adaptation: Traits that increase individual fitness in an environment
- Individuals with adaptations for a particular environment are more likely to survive and reproduce over time