DRAW IT Below are the amino acid sequences (using the
single-letter code; see Figure 5.14 ) of four short segments of the
FOXP2 protein from six species: chimpanzee (C), orangutan (O),
gorilla (G), rhesus macaque (R), mouse (M), and human (H).
These segments contain all of the amino acid differences
between the FOXP2 proteins of these species.
Use a highlighter to color any amino acid that varies among the
species. (Color that amino acid in all sequences.)
(a) The $C, G,$ R sequences are identical. Identify which lines
correspond to those sequences.
(b) The H sequence differs from that of the $\mathrm{C}, \mathrm{G}$ , R species at two
amino acids. Underline the two differences in the H sequence.
(c) The O sequence differs from the $\mathrm{C}, \mathrm{G}$ , R sequences at
one amino acid (having $\mathrm{V}$ instead of $\mathrm{A}$ ) and from the $\mathrm{H}$
sequence at three amino acids. Identify the O sequence.
(d) In the M sequence, circle the amino acid(s) that differ from
the $\mathrm{C}, \mathrm{G}, \mathrm{R}$ sequences, and draw a square around those that
differ from the H sequence.
(e) Primates and rodents diverged between 60 and 100 million
years ago, and chimpanzees and humans about 6 million
years ago. Compare the amino acid differences between
the mouse and the $\mathrm{C}, \mathrm{G}, \mathrm{R}$ species with those between the
human and the $\mathrm{C}, \mathrm{G}, \mathrm{R}$ species. What can you conclude?