1. In-Text Art, Ch. 16, p. 316 (1)

2. In-Text Art, Ch. 16, p. 316 (2)

3. In-Text Art, Ch. 16, p. 316 (4)

4. In-Text Art, Ch. 16, p. 317

5. Figure 16.1 Clades Represent All the Descendants of a Common Ancestor

6. Figure 16.2 The Bones Are Homologous, the Wings Are Not
Analogous trait = homoplasies
Shared derived trait = synapomorphies

7. Table 16.1 Eight Vertebrates and the Presence or Absence of Some Shared Derived Traits

8. Figure 16.3 Inferring a Phylogenetic Tree

9. A monophyletic group consists of the ancestor species and all its descendants
A polyphyletic grouping consists of various species with different ancestors
A paraphyletic grouping consists of an ancestral species and some, but not all, of the descendants
(a) Monophyletic group (clade)
(b) Paraphyletic group
(c) Polyphyletic group A A A B
Group  B B
Group  C C C D D D E E
Group  E F F F G G G 9

12. Individual genes vary in how clocklike they are
Molecular Clocks
A molecular clock uses constant rates of evolution in some genes to estimate the absolute time of evolutionary change
Assumption: nucleotide substitutions are proportional to the time since they last shared a common ancestor
Molecular clocks are calibrated against branches whose dates are known from the fossil record
Individual genes vary in how clocklike they are
© 2011 Pearson Education, Inc. 12

13. Divergence time (millions of years)90 60
Number of mutations 30
Figure A molecular clock for mammals. 30 60 90
120
Divergence time (millions of years) 13

14. Figure 16.9 A Molecular Clock of the Protein Hemoglobin

15. Problems with Molecular Clocks
The molecular clock does not run as smoothly as neutral theory predicts
Irregularities result from natural selection in which some DNA changes are favored over others
Estimates of evolutionary divergences older than the fossil record have a high degree of uncertainty
The use of multiple genes may improve estimates
© 2011 Pearson Education, Inc. 15

16. It is also important to distinguish homology from analogy in molecular similarities
Mathematical tools help to identify molecular homoplasies, or coincidences
Molecular systematics uses DNA and other molecular data to determine evolutionary relationships
© 2011 Pearson Education, Inc. 16

17. 1 1 2
Figure 26.8 Aligning segments of DNA. 17

18. 1 1 2 Deletion 2 1 2 Insertion Figure 26.8 Aligning segments of DNA.18

19. 1 1 2
Deletion 2 1 2
Insertion 3 1
Figure 26.8 Aligning segments of DNA. 2 19

20. 1 1 2
Deletion 2 1 2
Insertion 3 1
Figure 26.8 Aligning segments of DNA. 2 4 1 2 20

21. Figure 24.3 Amino Acid Sequences of Cytochrome c (Part 2)

22. Figure 24.1 Amino Acid Sequence Alignment (Part 1)

23. Figure 24.1 Amino Acid Sequence Alignment (Part 2)

24. Figure 24.2 Multiple Substitutions Are Not Reflected in Pairwise Sequence Comparisons