Natural Selection

5. Organisms produce more offspring than can survive, leading to competition.
7. An organism's ability to survive and reproduce, passing its genes to the next generation.
11. Processes that create new gene combinations, increasing genetic diversity.
13. compete for limited resources in their environment.
14. Changes in the DNA sequence, e.g., ATCCGTTAA → TTTCGTTAA, introducing new variation.
15. Selection favors the average trait, reducing variation.
16. Greater variation provides better adaptability, allowing populations to tolerate environmental changes.
17. Selection favors one extreme trait, shifting the population in that direction.

1. Environmental factors that favor certain traits over others, driving natural selection.
2. Selection favors two or more extreme traits, leading to a split in the population.
3. Changes in behavior that increase survival, e.g., migration, hibernation.
4. Fewer traits to select from, less tolerance to change, and increased susceptibility to disease (e.g., inbreeding).
6. Differences in traits that exist in a population, providing material for natural selection.
8. The process by which traits become more common over generations, leading to evolution.
9. A beneficial trait that improves an organism’s chances of survival and reproduction.
10. Leads to genetic variation; hybrid crosses can reintroduce recessive traits.
12. Humans select for desirable traits in plants and animals (e.g., dog breeding, crop improvement).