The Process of Speciation What is Speciation The
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The Process of 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 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 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 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 Canyon
Reproductive 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. Darwin’s Finches FOUNDERS ARRIVE GEOGRAPHIC ISOLATION REPRODUCTIVE ISOLATION ECOLOGICAL COMPETITION CHANGES IN THE GENE POOL CONTINUED EVOLUTION