The Process of SpeciationThe Process of Speciation
What is Speciation?What is Speciation?
• The formation of a new species
• Species: a group of organisms that can breed with one another and produce fertile offspring
• In order to create a different and new species, you must change the gene pool
• But, how do you change the gene pool?
Reproductive IsolationReproductive Isolation
• To create a new species, there must be isolation
• Reproductive Isolation: When members of 2 populations can no longer interbreed and produce fertile offspring; now have separate gene pools
• Caused by 3 ways
Behavioral IsolationBehavioral Isolation
• 2 populations are capable of interbreeding but have different courtship rituals– Bird of Paradise Mating Dance – Mating Calls/Songs Humpback Whale– Calls/Whistles of Meadowlark Bird
http://video.nationalgeographic.com/video/player/animals/
Geographic IsolationGeographic Isolation
• Two populations are separated by geographic barriers
• Ex: Rivers, Mountains, Bodies of Water
• May not be permanent (waters may flood together, land bridge between islands)
Squirrels and the Grand CanyonSquirrels and the Grand Canyon
Reproductive Temporal IsolationReproductive Temporal Isolation
• 2 or more species reproduce at different times
• Ex: 3 species of orchids release pollen
only one day a yr. Since they don’t release
pollen on the same day, they can never
cross pollinate or interbreed.
• Ex: eastern spotted skunk mates in late winter and western spotted skunk mates in late summer.
Pulling It All Together-Pulling It All Together-Darwin’s FinchesDarwin’s Finches
FOUNDERS ARRIVE GEOGRAPHIC ISOLATION
CHANGES IN THE GENE POOL
REPRODUCTIVE ISOLATION
ECOLOGICAL COMPETITION
CONTINUED EVOLUTION
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