LT 11.3: Speciation Story Assignment

Learning Target: I can explain how isolation of populations can lead to speciation.

Assignment Directions: Write a creative story that explains how one population of organisms splits into two or more new species over time. Your story must include the following scenes and use the terms Divergent Evolution, Speciation, and Reproductive Isolation. You may also use terms like geographic isolation, gene flow, genetic drift, coevolution, disruptive or diversifying selection, and convergent evolution if they fit your story. Be sure to describe each scene in detail, using scientific vocabulary and concepts. Your story should be at least one page in length and worth 20 points. Use the checklist below to make sure you include all required elements.

Your story must include the following scenes:

1. Description of the original population of organisms (Where do they live? What is their ecosystem like? What do they eat? What eats them? What diseases, parasites, or predators do they face?)
2. Description of what isolates the new population(s) from the original population (geographic isolation, reproductive isolation, different roles in the environment, migration, genetic drift, sizes, etc.)
3. Description of different selective pressures that are acting on the populations and the traits that survive better in the new isolated environment(s) (predators, disease, food available, ability to hide, competition, etc.)
4. Description of how the new population(s) change in their appearance or physiology (phenotype) because of the selective pressures in each environment or part of the environment the populations live in.
5. Description of how the populations become unable to reproduce together and form new species. Describe what type of barriers keep their gene pools apart: geographic isolation, habitat isolation, temporal isolation, behavioral isolation, mechanical isolation, gametic isolation, etc.
6. Description of how the new species are similar to the common ancestor and how they are different from the common ancestor.

Be sure to use the terms Divergent Evolution, Speciation, and Reproductive Isolation in your story.

Write a creative story that explains how one population of organisms splits into two or more new species through the process of adaptation and isolation. Your story must include all six scenes described above and use the required scientific terms. Be detailed and use your own words.