Chapter 16.3 Flashcards
Under what condiitions does natural selection occur?
When there is:
1) Struggle for existence (competitiion for food and resources)
2) Variation and Adaptation (generations have differences between individuals and some variations increase organisms ability to survive and reproduce)
3) Survival of the fittest (most fit is seen as individuals who can survive and reproduce well in their environment)
What does Darwin’s mechanism for evolution suggest about living and extinct species?
Natural Selection occurs in any situation in which:
1) more individuals are produced that can survive (struggle for existence)
2) there is a natural variation (variation and adaptation),
3) there is variable fitness among individuals (survival of the fittest).
Adaptation
any heritable characteristic that increases an organism’s ability to survive and reproduce in its environment
Fitness
how well an organism can survive and reproduce in its environment
Natural Selection
process by which organisms with variations most suited to their local environment survive and leave more offspring.
Artificial vs. Natural Selection
Artificial Selection = Nature provides the variation and humans control which ones get to reproduce that have desirable traits. This is goal directed.
Natural Selection = Nature also provides variation, but some organisms have a better chance to survive and reproduce and pass on their genes