Key concept: Key concept : Evolution occurs in patterns Evolution occurs in patterns • Evolution through natural selection is not random. • Natural selection can have direction Natural selection can have direction. • The effects of natural selection add up over time. Convergent E Convergent Evolution volution Defined : Describes evolution toward similar traits in unrelated species. • Survival advantage to a particular environment. • Ex: Tuna (fish) and dolphins (mammals). They are an ltd i li i i i il i t th unrelated species living inasimilar environment, the ocean. • Faced similar evolutionary pressures. Divergent Divergent Evolution volution red fox kit fox ancestor • Defined : Describes evolution toward different l l l d traits in closely related species. – Cause: Different environments
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Key concept :Key concept : Evolution occurs in patternsEvolution occurs in patternsy py p pp• Evolution through natural selection is not random.
• Natural selection can have directionNatural selection can have direction.• The effects of natural selection add up over time.
Convergent EConvergent Evolution volution
Defined: Describes evolution toward similar traits in unrelated species.
• Survival advantage to a particular environment.• Ex: Tuna (fish) and dolphins (mammals). They are an
l t d i li i i i il i t thunrelated species living in a similar environment, the ocean.• Faced similar evolutionary pressures.
Divergent Divergent EEvolution volution
red fox kit fox
ancestor
• Defined: Describes evolution toward different l l l dtraits in closely related species.
– Cause: Different environments
CoevolutionCoevolution
• Defined: Two or more species evolve in response to changes in each other– Evolutionary paths become connected– Both species receive benefits from the other as a result of adaptations.
• Ex: Plants and Insects– Plants: provide insects with nectar– Insect: transfers pollen from one plant to another
CoevolutionCoevolution Continued…Continued…
• Coevolution can occur in competitive relationships, sometimes called an evolutionary arms race.– Example: Crab vs. Snail & Bacteria vs. Humans
Evolutionary Arms Race Continued… Evolutionary Arms Race Continued… A tibi ti R i tA tibi ti R i tAntibiotic ResistanceAntibiotic Resistance
GoodBad
• Antibiotics: chemicals designed to kill bacteria– Produced by other microorganisms to fight bacteria
• Antibiotic Resistance: Bacteria are adapting to the use of antibioticsAntibiotic Resistance: Bacteria are adapting to the use of antibiotics– Overuse & misuse speeds up the process– Importance: Bacteria infections are becoming harder to treat
Species Species CCan an BBecome ecome EExtinct xtinct • Defined: The elimination of a species from EarthDefined: The elimination of a species from Earth.