Questions The Process of Speciation
A ______is a group of similar organisms that can potentially ______and produce ______offspring.
Why "fertile?"
So what is the difference between a species and a population?
- A ______is a group of individuals of the ______species that interbreed and reproduce.
______is the formation of ______species.
Speciation is the ultimate consequence of ______! Enough change over time occurs that related organisms can no longer breed and produce fertile offspring. = ______.
______occurs when formerly interbreeding species or populations separate so that they cannot produce fertile offspring.
How do you think reproductive isolation can occur?
3 Types of Reproductive Isolation These are "______mechanisms" that could lead to speciation.
Isolating = ______
1. Geographic Isolation ______occurs when two populations are separated ______by geographic barrier.
Ex. rivers, mountains, or stretches of water, lava, ______.
Ex. Galapagos finches! different islands, ultimately different species
Ex. The kaibab squirrel lives on the north side of the grand ______and the abert squirrel lives on the south side!
Ex. Bonobos are also known as "left bank" chimpanzees.
Chimpanzees are "right bank" chimps. They are separated by the Congo ______
How did the pollenpeepers in the PBS activity become geographically isolated?
2. Temporal Isolation "Temporal" = relating to time
______occurs when two populations reproduce at different ______.
Ex. There are 4 groups of Chinook salmon who spawn at different times of the year along California's central coast: winter, spring, summer and fall. The populations who breed in one ______never breed with those in another ______.
3. Behavioral Isolation ______occurs when two populations have differences in ______rituals or ______that prevent them from interbreeding.
Example: eastern and western meadowlarks will not mate with each other because they use different ______to attract mates.
Ex. Two species of tree frogs that live side-by-side in the southeastern U.S. have different ______.
How does isolation lead to speciation? Organisms that are isolated respond differently to ______and have different ______.
They could ______to become so ______different that they can no longer breed and produce fertile offspring.
So, even if they were brought together in a zoo, they still couldn't have fertile offspring.
Ex. Their chromosomes cannot form homologues in meiosis.
SUMMARY______