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___________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ ___________________________________________________________________ .