Download Section 14-4

Answers ws 14-4 The Development of New Species p. 304
1. Define speciation.
how new species evolve from old ones
2. Define niche.
The combination of an organism's "profession" and the place in which it lives
3. Why does 1 species drive the other one to extinction if 2 species occupy the same niche in the same location for a long period of
time? They will compete with each other for food and space, one will not survive because it will not be as efficient
4. Why is it an advantage for 2 species to occupy different niches? Not compete with each other as much
5. What do all species share? Common gene pool
6. Define reproductive isolation. The separation of populations so that they do not interbreed
7. What occurs when the gene pool of a population is reproductively isolated? Natural selection can work differently on each group,
adaptations that appear in one group are not passed to the other
8. List 3 examples of geographic reproductive isolation. Rivers, mountains, roads
9. How do you think how differences in courtship behaviour (fg 14-17), physical appearance (fg 14-15), or differences in fertile
periods may result in reproductive isolation? Each may not want to reproduce with the other organism because of these differences
may only reproduce with individuals that are similar to themselves
10. What does natural selection do to reproductively isolated populations? It increases the differences between the separated
populations as each becomes better adapted to each different environment
11. What happens to the gene pools of these populations? Their separate gene pools gradually become more dissimilar
12. List three ways the 2 populations are separated. Physical barriers, behavioural barriers, very different genes
13. What is the final step in becoming a separate species. Reproductive isolation becomes permanent: no longer different populations
anymore but a new species
14. Darwin’s Finches: An Example of Speciation: Where did Darwin’s 13 finches come from (fg 14-18)? South American mainland
15. If each species came from a common ancestor, what main factor allows them to co-exist? Each species exhibits body structures
and behaviours that enable it to live in a separate niche
16. What are the 3 “factors” that lead to the formation of a new species? Geographic & behavioural barriers and reproductive isolation
17. Darwin’s finches 5 steps of speciation: What are the founding fathers and mothers? The 1st few members of the species to arrive
in the new area
18. Step 2: How did the birds from island “A” become separated? Some birds flew from island A to island B (storm?)
19. What prevented the blending of their gene pools with island A?
ocean between them. They do not like to fly over water.
20. Changes in the Gene Pool: What was the natural selector causing the birds of island “A” to differ from island “B”
types of food on each island
21. Reproductive Isolation: Why do the gene pools of Island “A” not mix with island “B”?
Each member of each island is so different from each other that they do not want to mate with each other
22. Sharing the Same Island: What are the 3 possibilities when species “A” and “B” come together on island B? coexistence,
extinction, or further evolution
23. Give an example what must occur in order to: a) coexist if the 2 species occupy different niches
24. b) become extinct
if the 2 species are to similar they will compete for resources with each other until 1 goes extinct
25. c) undergo further evolution if 1 species has enough genetic variation, 1 of the species may continue to evolve
26.
Speciation and Adaptive Radiation: Define adaptive radiation and give an example.
One species gives rise to many species
27.
Another name for adaptive radiation is? Divergent evolution
28.
What do niches have to do with adaptive radiation? Each new species must have its own niche to occupy
29.
Give 2 examples of adaptive radiation. (fg 14-20, fg 14-21) 43 different species of Hawaiian honeycreepers evolve from 1, modern
day birds, mammals, and reptiles evolved from 1 type of reptile
30.
Give an example of a homologous structure from chapter 13. same structure (origin), different function
bird wing, dog arm
31.
Explain the relationship between adaptive radiation and homologous structures. During adaptive radiation, one main group
(similar) of organisms evolve a variety of characteristics that enable them to survive and fill new niches → new species
32.
How is adaptive radiation related to convergent evolution? Adaptive radiations (speciation) among different organism produce
species that are similar in appearance and behaviour.
33.
Define convergent evolution. Type of adaptive radiation that occurs amoung different starting organisms. They are similar in
appearance and function but different in structure and origin
34.
Define analogous structures. Structures that are similar in appearance and function, but they have different origins
35.
Give 3 examples of analogous structures. Wings of butterflies, birds, and bats: very different origins
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