click below
click below
Normal Size Small Size show me how
Unit 15
Speciation
Question | Answer |
---|---|
Species | A population of organisms which is reproductively isolated from other populations of organisms |
Speciation | The evolution of reproductive isolation in two populations which previously interbred |
Reproductive Isolation | The inability of populations to interbred such as to produce a merger of separate gene pools. |
Allopatric | Speciation occurs in two separate areas Usually involving some geographic barrier i.e. river, canyon, open ocean, mountain range think allocate |
Sympatric | Speciation occurs in the same area Usually involves some sudden mutation Think same |
Parapatric | Speciation occurs in two adjacent areas Anthoxanthum is an example |
Be able to identify the significance of reproductive isolation to speciation | allows species to mate and productive viable offspring |
Temporal isolation | Two species mate at different times of the year or the day Think time Maryland Giant is an example Pre-zygotic |
Habitat Isolation | Two species reproduce in different habitats Pre-zygotic |
Behavioral Isolation | Songs, dance behaviors, visual cues Pre-zygotic |
Mechanical Isolation | anatomical differences that prevent species from interbreeding species are only built to mate with their own species. Pre-zygotic |
Gametic incompatability | Egg and sperm cells do not chemically recognize each other Pre-zygotic |
Zygote (hybrid) mortality | Sperm and egg fuse but the offspring fail to develop Post-zygotic |
Hybrid Sterility | the two species mate, produce offspring, but the offspring are not fertile Post-zygotic Example: Liger, Mule |
Hybrid Inviability | the hybrid offspring cannot survive long enough to reproduce Post-zygotic |