speciation. biological species concept population that can interbreed to produce viable and fertile...

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