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- The five main elements of natural selection are.
- ) All species have genetic variation.
- ) Changing environments can affect the survival of a species.
- ) Individuals of a species need to compete for survival status. (Food, Shelter, Mates.)
- ) Those individuals that have advantages for survival tend to leave more offspring than those individuals that don't.
- ) The characteristics of the individuals best suited for survival tend to increase in a population over time.
- As populations of the same species encounnter different living environments and reproductive isolation, natural selection can occur for different characteristics causing a new species to form.
- The way in which an organism forms a relaationship with its environment is called adaptation.
- The offspring of an organism are not all the same but vary in small details.
- The variations that are best adapted for the survival of the organism will increase its chances to survive and reproduce.
- Adaptations can become very complex throuugh a series of slight variations over many generations.
- Every detail of an organism's body and beehavior is shaped by nature.
- A species is a population of organisms thhat can interbreed to produce healthy and fertile offspring.
- Speciation occurs as a result of reproducctive isolation of portions of a population.
- Most speciation occurs geographically wheen geographic barriers prevent contact between portions of a population. Over time genetic variations tend to drift apart between the separated organisms. Rapid changes in the genes of an isolated population are known as genetic drift.
- Divergent evolution occurs when one speciies evolves into two or more species with different characteristics.
- Some plants can create genetic differencees by doubling their chromosome number.
- Convergent evolution shows that similar aadaptive traits may arise independently more than once. Convergent evolution occurs in unrelated species that live in similar environments.
- Many scientists believe that evolution iss a series of slow and steady changes (gradualism) punctuated by infrequent episodes of very rapid change (punctuated equilibrium).
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