Name _________________________________________________
Chapter 17 Reading Guide
Speciation
Concept 17.1 Species Are Reproductively Isolated Lineages on the Tree of Life
1. What is common definition of a species?
2. What is speciation?
3. Biologists use the term species in different ways based on the specific questions they ask about species.
Explain the three major classes of species concepts discussed in the text and discuss the limitations of each.
a) Morphological Species Concepts –
b) Biological Species Concept –
c) Lineage Species Approach –
4.
What is a lineage and where does a lineage start and stop?
5. What makes reproductive isolation such an important component of each of the species concepts?
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Concept 17.2 is beyond the scope of this course.
Concept 17.3 Speciation May Occur through Geographic Isolation or in Sympatry
6. What is allopatric speciation?
7. What are sister species?
8. What is sympatric speciation?
9. What is the most common means of sympatric speciation? What types of organisms is this most common
in?
10. Explain how speciation via polyploidy can happen in only two generations.
Concept 17.4 Reproductive Isolation Is Reinforced When Diverging Species Come into Contact
11. Explain how these different types of prezygotic isolating mechanisms prevent hybridization between
species.
a) Mechanical Isolation –
b) Temporal Isolation –
c) Behavioral Isolation –
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d) Habitat Isolation
e) Gametic Isolation –
12. Explain the following postzygotic isolating mechanisms result in selection against hybridization.
a) Low hybrid zygote viability –
b) Low hybrid adult viability -
c) Hybrid infertility –
13. What is a hybrid zone?
STOP & WATCH:
Bozeman Speciation https://www.youtube.com/watch?v=rlfNvoyijmo
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