Further Thought

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Further Thought

Use the questions at the end of the chapter to explore concepts and connections in greater depth through application and synthesis.

1. What is a synapomorphy? [Hint]
To create paragraphs in your essay response, type at the beginning of the paragraph, and at the end.

2. Why do the characters that are used to infer phylogenies have to be independent of each other? [Hint]
To create paragraphs in your essay response, type at the beginning of the paragraph, and at the end.

3. What is homoplasy? Explain the difference between convergence and reversal. [Hint]
To create paragraphs in your essay response, type at the beginning of the paragraph, and at the end.

4. What is parsimony? [Hint]
To create paragraphs in your essay response, type at the beginning of the paragraph, and at the end.

5. What are some of the advantages and disadvantages of using morphological and molecular traits to infer phylogenies? [Hint]
To create paragraphs in your essay response, type at the beginning of the paragraph, and at the end.

6. How can researchers defend the claim that certain traits are homologous? [Hint]
To create paragraphs in your essay response, type at the beginning of the paragraph, and at the end.

7. How can researchers defend the claim that certain traits are derived or ancestral? [Hint]
To create paragraphs in your essay response, type at the beginning of the paragraph, and at the end.

8. Explain why traits might be similar due to convergent evolution. Give an example of morphological traits that are analogous. [Hint]
To create paragraphs in your essay response, type at the beginning of the paragraph, and at the end.

9. Explain the difference between monophyletic and paraphyletic groups. Give an example of each. [Hint]
To create paragraphs in your essay response, type at the beginning of the paragraph, and at the end.

10. Why are evolutionary relationships only revealed by analyzing synapomorphies? [Hint]
To create paragraphs in your essay response, type at the beginning of the paragraph, and at the end.

11. Why does homoplasy tend to thwart efforts to estimate the evolutionary history of species accurately? [Hint]
To create paragraphs in your essay response, type at the beginning of the paragraph, and at the end.

12. Explain the difference between cladistic and phenetic approaches to inferring phylogenies. [Hint]
To create paragraphs in your essay response, type at the beginning of the paragraph, and at the end.

13. Explain the difference between cladistic and phenetic approaches to classifying the diversity of life. [Hint]
To create paragraphs in your essay response, type at the beginning of the paragraph, and at the end.

14. Why is using parsimony an effective way to minimize the probability that a phylogeny has been constructed from characters that show homoplasy? [Hint]
To create paragraphs in your essay response, type at the beginning of the paragraph, and at the end.

15. In the case of the whale astralagus, why was it misleading to use parsimony when inferring the phylogeny of artiodactyls? [Hint]
To create paragraphs in your essay response, type at the beginning of the paragraph, and at the end.

16. What is a molecular clock? When and why should molecular clocks work? [Hint]
To create paragraphs in your essay response, type at the beginning of the paragraph, and at the end.

17. In Figure 14.6 (page 559 in your textbook), site 192 was considered "variable but uninformative." Why is it uninformative? [Hint]
To create paragraphs in your essay response, type at the beginning of the paragraph, and at the end.

18. Make a figure analogous to Figure 14.3 (page 555 in your textbook) that illustrates what happens when convergent evolution occurs in a DNA sequence. [Hint]
To create paragraphs in your essay response, type at the beginning of the paragraph, and at the end.

19. High-crowned teeth that are well suited for grazing are found in some rodents (Rodentia), rabbits and hares (Lagomorpha), most cloven-hoofed animals (Artiodactyla), horses (Perissodactyla), and elephants (Proboscidea). Examine Figure 14.16 (page 579 in your textbook), which shows the relationships of these and other mammalian orders. Are high-crowned teeth a synapomorphy or a product of convergent evolution? [Hint]
To create paragraphs in your essay response, type at the beginning of the paragraph, and at the end.

20. According to Figure 14.16 (page 579 in your textbook), are the ungulates (artiodactyls and perrisodactyls) a monophyletic group or a paraphyletic group? Draw arrows on the tree indicating where the hoofed-foot trait was gained and/or lost. In your opinion, should the name ungulate still be used? [Hint]
To create paragraphs in your essay response, type at the beginning of the paragraph, and at the end.

21. Examine the three primate phylogenies shown in Figure 14.17 (page 580 in your textbook). Do the three phylogenies show the same relationships and the same order of branching? Do they give different impressions of whether there was a "goal" of primate evolution or what the "highest" primate is? Explain. [Hint]
To create paragraphs in your essay response, type at the beginning of the paragraph, and at the end.

22. Do base pairs from different positions in the same gene represent independent information? Why do researchers try to include as many genes in their analysis as their computers can handle? [Hint]
To create paragraphs in your essay response, type at the beginning of the paragraph, and at the end.

23. Figure 14.18 (page 580 in your textbook) shows the phylogeny of some ant species that farm fungi for food, along with the phylogeny of the fungal species that they have domesticated. Does cospeciation occur in these interacting species? Explain. [Hint]
To create paragraphs in your essay response, type at the beginning of the paragraph, and at the end.

24. Darwin maintained that there is no such thing as a higher or lower animal or plant. Explain what he meant. [Hint]
To create paragraphs in your essay response, type at the beginning of the paragraph, and at the end.




1.	What is a synapomorphy? [Hint] To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.



2.	Why do the characters that are used to infer phylogenies have to be independent of each other? [Hint] To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.



3.	What is homoplasy? Explain the difference between convergence and reversal. [Hint] To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.



4.	What is parsimony? [Hint] To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.



5.	What are some of the advantages and disadvantages of using morphological and molecular traits to infer phylogenies? [Hint] To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.



6.	How can researchers defend the claim that certain traits are homologous? [Hint] To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.



7.	How can researchers defend the claim that certain traits are derived or ancestral? [Hint] To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.



8.	Explain why traits might be similar due to convergent evolution. Give an example of morphological traits that are analogous. [Hint] To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.



9.	Explain the difference between monophyletic and paraphyletic groups. Give an example of each. [Hint] To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.



10.	Why are evolutionary relationships only revealed by analyzing synapomorphies? [Hint] To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.



11.	Why does homoplasy tend to thwart efforts to estimate the evolutionary history of species accurately? [Hint] To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.



12.	Explain the difference between cladistic and phenetic approaches to inferring phylogenies. [Hint] To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.



13.	Explain the difference between cladistic and phenetic approaches to classifying the diversity of life. [Hint] To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.



14.	Why is using parsimony an effective way to minimize the probability that a phylogeny has been constructed from characters that show homoplasy? [Hint] To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.



15.	In the case of the whale astralagus, why was it misleading to use parsimony when inferring the phylogeny of artiodactyls? [Hint] To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.



16.	What is a molecular clock? When and why should molecular clocks work? [Hint] To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.



17.	In Figure 14.6 (page 559 in your textbook), site 192 was considered "variable but uninformative." Why is it uninformative? [Hint] To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.



18.	Make a figure analogous to Figure 14.3 (page 555 in your textbook) that illustrates what happens when convergent evolution occurs in a DNA sequence. [Hint] To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.



19.	High-crowned teeth that are well suited for grazing are found in some rodents (Rodentia), rabbits and hares (Lagomorpha), most cloven-hoofed animals (Artiodactyla), horses (Perissodactyla), and elephants (Proboscidea). Examine Figure 14.16 (page 579 in your textbook), which shows the relationships of these and other mammalian orders. Are high-crowned teeth a synapomorphy or a product of convergent evolution? [Hint] To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.



20.	According to Figure 14.16 (page 579 in your textbook), are the ungulates (artiodactyls and perrisodactyls) a monophyletic group or a paraphyletic group? Draw arrows on the tree indicating where the hoofed-foot trait was gained and/or lost. In your opinion, should the name ungulate still be used? [Hint] To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.



21.	Examine the three primate phylogenies shown in Figure 14.17 (page 580 in your textbook). Do the three phylogenies show the same relationships and the same order of branching? Do they give different impressions of whether there was a "goal" of primate evolution or what the "highest" primate is? Explain. [Hint] To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.



22.	Do base pairs from different positions in the same gene represent independent information? Why do researchers try to include as many genes in their analysis as their computers can handle? [Hint] To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.



23.	Figure 14.18 (page 580 in your textbook) shows the phylogeny of some ant species that farm fungi for food, along with the phylogeny of the fungal species that they have domesticated. Does cospeciation occur in these interacting species? Explain. [Hint] To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.



24.	Darwin maintained that there is no such thing as a higher or lower animal or plant. Explain what he meant. [Hint] To create paragraphs in your essay response, type <p> at the beginning of the paragraph, and </p> at the end.

Chapter 14: Reconstructing Evolutionary Trees

Further Thought