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