Amino Acid Sequences and Evolutionary Relationships
Mrs. Gumberg
Honors Biology -- Period 5
17 April 2012

Jason Kang and Tasha Merchant
Purpose: to discover how amino acid sequences provide evidence for evolution and how they infer evolutionary relationships among some organisms.
Method:
To perform this experiment, we first needed to distinguish the differences in the amino acid sequences of vertebrae animals such as the human, chimpanzee, gorilla, rhesus monkey, horse, and kangaroo. Once we finished this, we graphed the differences on a bar graph, comparing each species' amino acid sequence to that of a human. Next, we observed more organisms such as the fruit fly, dogfish shark, pigeon, screwworm fly, silkworm moth, tobacco hornworm moth, and wheat, and counted the number of differences in their amino acid sequences. We then graphed it, comparing the number of differences to the AA sequence of a fruit fly.
Results:
Organisms
Number of Amino Acid Differences
Position In Which They Vary
Human and Chimpanzee
Zero
-
Human and Gorilla
One
104
Human and rhesus monkey
Two
87, 104
Human and Horse
Five
87, 111, 112, 114, 116
Human and Kangaroo
Seven
87, 104, 109, 110, 112, 113, 116

For the different Amino Acid (AA) sequences, we used the human as the standard and compared it with various organisms. These organisms consisted of; chimpanzees, gorillas, rhesus monkeys, horses, and kangaroos. Results show that the chimpanzee, gorilla, and rhesus monkey are very much alike to humans because they have two to none AA differences. Furthermore, they are the only animals that have thumbs.
Species Paring
Number of differences
Human-chimpanzee
0
Human-fruit fly
29
Human-horse
12
Human-pigeon
12
Human-red bread mold
48
Human-rhesus monkey
1
Human-snapping turtle
15
Human-tuna
21
Human-wheat
43

With the AA differences between human and other organism and using human cytochrome c as the standard, the chimpanzee had no differences again. However, the red-bread mold had the most differences with 48 differences.
Discussion:
For this lab, we compared the biochemical similarities of organism to