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Geographic Isolation
- PREZYGOTIC
- a. by VICARIANCE: Glaciation of Kamchatka peninsula in Russa sep. polar bear pop from ancestral brown bear pop.
- b. by DISPERSAL: rare island hopping across OCEAN barriers allowed Reproductive isolation among Hawaiian populations of Drosophila
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Temporal Isolation
- PREZYGOTIC
- Isolation by hours, days or SEASONS
- ie, In N America, Eastern spotted skunks breed in Spring, isolating them from Western spotted skunks- breed in Fall
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Habitat Isolation
- PREZYGOTIC
- by sympatry (same geograph region) or parapatry (diff geo region)
- Rhagoletis pomonella feeds on APPLES, diverged from the Ancestral population feeding on Hawthorn fruits in Eastern N America.
- These maggots also isolated by breeding times (temporal) and genetic diff
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Behavioral or Pollinator isolation
- PREZYGOTIC
- White Eyed Drosophilia: lower mating success than red-eyed. even white eyed don't like to mate w/white eyed
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Mechanical Isolation
- PREZYGOTIC
- Different species of Dragonflies cannot mate b/w 4 wings do NOT FIT properly to mate
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Gametic Isolation
- PREZYGOTIC
- Male GAMETES from one deer species CANNOT survive in female reproductive tract of another deer species
- sperm doesn't survive
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Ecological F1 Inferiority
- POST-ZYGOTIC
- EXTRINSIC barrier
- Anthoxanthum odoratum hybrids b/w metal tolerant and intolerant cannot compete w/either parental variety.
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Behavioral F1 Inferiority
- I'm Not COOL ENOUGH
- POST-ZYGOTIC
- EXTRINSIC barrier
- Canis lupus (gray wolf) crossed w/Canis latrans (western coyote) yield F1 HYBRIDS (northeastern coyote), but these have LOW mating success rate
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F2 Hybrid Breakdown
- POST-ZYGOTIC
- INTRINSIC barrier
- Gossypian barbadense (Egyptian cotton) crossed w/Gossypium hirsutum yield F1 hybrids that are Fertile…BUT when these F1s CROSS = INVIABLE F2 hybrids
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F1 Hybrid sterility
- POST-ZYGOTIC
- INTRINSIC barrier
- Equus caballens mares (female horses) mating w/Equss ascius stallions (male donkeys) = mules (Healthy & strong, but usually STERILE..males always are)
- Horses have different diploid chrom than donkey
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F1 Hybrid inviability
- POST-ZYGOTIC
- INTRINSIC barrier
- Copper-tolerant populations of yellow monkey flower (Mimulus guttatus) when crossed w/copper sensitive populations produce mostly INVIABLE F1 hybrids based on mutant allele for copper tolerance arising in copper sensitive pop 100yrs ago
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