Speciation
Biological Species Concept
Population that can interbreed to produce viable and fertile offspring
Eastern Meadowlark Western Meadowlark
Biological Species Concept
Cannot breed, different songs, different behaviors
Speciation
Formation of a new species
How does Speciation occur?
- Gene pools become separated- Populations become reproductively isolated
Reproductive Isolation
Biological barriers that prevent members from producing viable and fertile offspring
Reproductive Isolation Pre-zygotic (before the zygote)
Habitat Isolation
2 species, 2 different habitats within same area
Rarely cross paths
Temporal Isolation
Eastern Spotted Skunk
Western Spotted Skunk
Reproduce late winter
Reproduce late summer
Breed at different times(day/season/year)
Cannot mix gametes
Behavioral Isolation
Courtship rituals that are uniqueto breeding success
Mechanical IsolationMorphological
differences that prevent mating
Gametic Isolation
Purple Sea Urchin Red Sea Urchin
Sperm of #1 not able to fertilize egg of #2Sperm cannot survive, cannot penetrate egg
Reproductive Isolation Post-zygotic (after the zygote)
Hybrid Equine
Zebroid or Zorse - sterile
Viable (able to survive)Infertile (not able to reproduce)
Zedonk, Zebrass - sterile
Offspring = Mule = sterile
Horse
Donkey
Offspring = Hinny = sterile
Horse