Transcript The Process of Speciation - Kent City School District

The Process of Speciation
16-3
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
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
Pulling It All TogetherDarwin’s Finches
FOUNDERS ARRIVE
GEOGRAPHIC
ISOLATION
REPRODUCTIVE
ISOLATION
ECOLOGICAL
COMPETITION
CHANGES IN THE
GENE POOL
CONTINUED
EVOLUTION