Speciation Webquest Bell 2019 Hon Bio PDF

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Name: Amanda Rumack

Date: 3/16/19

Speciation Webquest Click on this link (http://evolution.berkeley.edu/evolibrary/article/0_0_0/evo_40) to answer the questions on this page. No copying and pasting! Write all your answers in red.

1. Define “species”. A species is a group of individuals/organisms that can or do interbreed in nature 2. Do organisms have to look identical in order to be the same species? Organisms do not have to look identical in order to be the same species.

3. Why isn’t the simplified definition of a species from question #1 100% accurate? It is not 100% accurate because bacteria or other organisms that reproduce asexually does not really fit into the previous definition. a. Give an example of a type of organism that is an exception. Bacteria 4. Define “speciation”. An event that occurs in lineages where two or more new species are formed. 5. In the story of the fruit flies, what initial event caused the fruit flies to be separated? A hurricane 6. What causes the mainland population of fruit flies to start to become different from the island fruit flies? The island fruit flies are now changed because of morphology, food preferences, and courtship displays and are now different than the mainland flies. Random events on the island differ from those on the mainland, so that is another reason why they are different. 7. Once the island fruit flies reunite with the mainland fruit flies, give 2 reasons why they won’t/can’t interbreed. a. They won’t interbreed because they have different courtship behaviors now. b. Their genetic differences will not allow them to interbreed. 8. What is the term we use for what caused this speciation event? Geographic Isolation 9. Give 4 examples of what can cause your answer to #8 to occur. -rivers change course -Mountains rise -organisms migrate -continents drift apart

Name: Amanda Rumack

Date: 3/16/19

10. What else can cause speciation to occur (other than geographic isolation)? Reduction of gene flow 11. Define “incipient species”. A group of organisms that is about to become a separate species from other, related individuals. 12. Define “allopatry”. Speciation that depends on an external barrier to gene flow (such as geographic isolation) to begin or complete the process of speciation. 13. In any speciation event, what is absolutely necessary for speciation to occur? In any speciation event it is absolutely necessary that the two incipient species are unable to produce viable offspring together or that they avoid mating with members of the other group. 14. What is the example we talked about in class that is an example of offspring sterility (hint: it can really pull a plow)? A mule 15. What was the allopatry that began the fruit fly speciation event? The hurricane 16. What caused the 2 fruit fly populations to diverge genetically? The food preference of the flies caused them to diverge genetically 17. What did the fruit fly food preference cause? It caused the flies to not be able to mate since flies meet by hanging around the same fruit, and since they had different food preferences the fruit flies and mainland flies didn’t meet. 18. Look at the diagram of the spotted owl population and notice the scientific name of each? Why do you think there are 3 words in the scientific name instead of 2? I think that there are three words in the scientific name because scientists need to be able to tell which spotted owl it is and where it is from. 19. Look at the fruit flies in the diagram used to explain Diane Dodd’s fruit fly experiment. What differences in the 2 resulting fruit fly populations could have caused each to prefer their own kind (the answer to this question is not in the text but think about mating preferences)? The differences in the 2 resulting fruit fly populations that could have caused each to prefer their own kind could be their food preference, since they were fed different starches.

Name: Amanda Rumack

Date: 3/16/19

20. Below, sketch a scenario in which a population of animal, plant or bacteria undergoes a speciation event. You MUST SHOW/INDICATE at least 1 barrier to ge

tive isolation (mating

location/time/rituals or offspring inviability/sterility) or ge

21. Open the Origin of Species powerpoint (BB>>Class Documents>>Unit 8) a. Differentiate allopatric and sympatric speciation. Allopatric speciation is when there is geographic separation Sympatric speciation is when the species still live in the same area b. Briefly describe each of these pre-zygotic barriers: i. Geographic isolation: when a geographical feature separated the species ii. Ecological isolation: when the ecology surrounding the species is different iii. Temporal isolation: when the seasons of breeding separates the species iv. Behavioral isolation: when the behaviors separate the species v. Mechanical isolation: when the morphological differences of the species do not allow them to mate vi. Gametic isolation: when the species’ gametes do not allow them to mate

c. Briefly describe each of these post-zygotic barriers: i. Reduced hybrid viability: genes of different parent species may interact and impar the hibrid’s development ii. Reduced hybrid fertility: even if hybrids are vigorous they may be sterile iii. Hybrid breakdown: hybrids may be fertile and viable in first generation, but when they mate ofpsring are feeble or sterile

d. Differentiate gradualism and punctuated equilibrium. Gradualism is divergence over long spans of time, and punctuated equilibrium is the idea that the rate of speciation is not constant....