Below are the amino acid sequences (using single letters;...

Below are the amino acid sequences (using single letters; see Figure 5.14 ) of three short segments of the FOXP2 protein from five species. These segments contain all amino acid differences between the FOXP2 proteins of these species. Compare the amino acid sequences by answering parts (a)-(d). Chimpanzee PKSSD ... TSSTT ... NARRD Mouse PKSSE ... TSSTT ... NARRD Gorilla PKSSD ... TSSTT ... NARRD Human PKSSD ... TSSNT ... SARRD Rhesus monkey PKSSD ... TSSTT ... NARRD (a) Circle the names of any species that have identical amino acid sequences for the FOXP2 protein. (b) In the sequence for the mouse, circle any amino acid that differs from the sequence for the chimpanzee, gorilla, and rhesus monkey. Then draw a box around any amino acid that differs from the human sequence. (c) In the human sequence, underline any amino acid that differs from the sequence for the chimpanzee, gorilla, and rhesus monkey. (d) Primates and rodents diverged about 65 million years ago, and chimpanzees and humans diverged about 6 million years ago (see Figure 21.17 ). How many amino acid differences are there between the sequence for the mouse and the sequence for the chimpanzee, gorilla, and rhesus monkey? How many amino acid differences are there between the human sequence and the sequence for the chimpanzee, gorilla, and rhesus monkey? Based solely on the numbers of amino acid differences occurring over these time periods, what might you hypothesize about the rate of evolution of the $F O X P 2$ gene? Based on the information in the chapter regarding the FOXP2 gene, is your hypothesis correct?

Below are the amino acid sequences (using single letters; see Figure 5.14 ) of three short segments of the FOXP2 protein from five species. These segments contain all amino acid differences between the FOXP2 proteins of these species. Compare the amino acid sequences by answering parts (a)-(d).
Chimpanzee PKSSD ... TSSTT ... NARRD
Mouse PKSSE ... TSSTT ... NARRD
Gorilla PKSSD ... TSSTT ... NARRD
Human PKSSD ... TSSNT ... SARRD
Rhesus monkey PKSSD ... TSSTT ... NARRD
(a) Circle the names of any species that have identical amino acid sequences for the FOXP2 protein.
(b) In the sequence for the mouse, circle any amino acid that differs from the sequence for the chimpanzee, gorilla, and rhesus monkey. Then draw a box around any amino acid that differs from the human sequence.
(c) In the human sequence, underline any amino acid that differs from the sequence for the chimpanzee, gorilla, and rhesus monkey.
(d) Primates and rodents diverged about 65 million years ago, and chimpanzees and humans diverged about 6 million years ago (see Figure 21.17 ). How many amino acid differences are there between the sequence for the mouse and the sequence for the chimpanzee, gorilla, and rhesus monkey? How many amino acid differences are there between the human sequence and the sequence for the chimpanzee, gorilla, and rhesus monkey? Based solely on the numbers of amino acid differences occurring over these time periods, what might you hypothesize about the rate of evolution of the $F O X P 2$ gene? Based on the information in the chapter regarding the FOXP2 gene, is your hypothesis correct?

Key Concepts

Amino Acid Sequence Representation

Proteins are composed of amino acids that are often abbreviated by single-letter codes. This method of representation condenses the protein sequence into a manageable format, allowing for straightforward comparisons between different organisms and enabling the identification of specific changes or mutations in the sequence.

Comparative Sequence Analysis

Comparative sequence analysis involves aligning multiple protein or gene sequences to identify similarities and differences. By comparing homologous segments across species, researchers can pinpoint amino acid substitutions and other changes that have occurred over evolutionary time, providing insights into functional conservation and divergence.

Amino Acid Substitution and Protein Evolution

Amino acid substitutions are the result of mutations that change one or more residues in a protein sequence. These changes can be neutral, deleterious, or occasionally beneficial, and tracking their occurrences across species helps in understanding how proteins evolve. The frequency and location of substitutions can shed light on regions of the protein that are critical for function versus those that may tolerate variability.

Molecular Clock and Evolutionary Rate Estimation

The molecular clock concept posits that genetic mutations accumulate at a relatively constant rate over time, which allows scientists to estimate the timing of evolutionary events. By comparing the number of amino acid differences between species with known divergence times, researchers can infer the rate at which protein sequences evolve. This method is fundamental for correlating genetic change with temporal scales in evolutionary biology.

Transcript

00:01 So this is a question where we have five different species and some segments of a gene called fox p2.

00:11 And then these segments are going to have amino acid differences between some of these species.

00:18 And then we're going to compare them and answer questions about it.

00:24 So we have chimpanzee, mouse, gorilla, human, recess, and a racist monkey.

00:28 As you notice, for the five are all primates, with three of them being apes, our first part is circle the names of any species that have identical amino acid sequences for the fox p2 protein.

00:45 Okay, so we're going to run through our list.

00:48 Chimpanzee is not identical to mouse.

00:53 I misspoke.

00:53 We're going to run through this part real quick, see what we can cross off.

00:57 So chimp is not identical to mouse, but it is identical to the mouse.

01:01 Other four so then in this part chimp it's identical to mouse but it doesn't matter because the first segment doesn't match it's a the next part is identical to gorilla and then it's identical to rhesus monkey but it's not identical to humans there's a n where there should be a t and the last part for chimp it is identical to gorilla and it's still identical to recess monkey.

01:41 So chimps, humans, or racist monkeys all have the same amino acid sequences.

01:52 It says the circle.

01:54 I'm just going to put a little dot because otherwise this is going to get really messy really quick.

02:01 We'll change it up.

02:02 We'll do blue.

02:03 So the next one is in the sequence for the mouse, so this one, circle, any amino acid that differs from a sequence from the chimp, gorilla, and rhesus monkey.

02:16 So, as we mentioned earlier, this mouse has an e, where there should be a d compared to the others.

02:24 And then it's next to those all match up to chimp, gorilla, and the rhesus macaque, or the rhesus monkey.

02:34 We're going to cross that off.

02:36 And the next part of it is stating, draw a box around any amino acid that difference.

02:42 First from the human sequence.

02:45 Well, this also differs.

02:52 Let's see, here's human.

02:54 The n is what is also differentiate.

02:59 And then human also has an s...