Final answer:
Two organisms with a high degree of similarity in their amino acid sequences are more closely related evolutionarily. This similarity indicates shared ancestry and is used to determine phylogenetic relationships.
Step-by-step explanation:
If two organisms have many of the same amino acid sequences, they would be more related to each other. This is because closely related species tend to have a greater proportion of their DNA and protein sequences in common. The similarity in amino acid sequences is due to their inherited DNA from a common ancestor, and it serves as evidence of their evolutionary kinship.
For instance, the closer similarity of amino acid sequences found in human cytochrome c compared to those in chimpanzees and rhesus monkeys supports the idea that humans share a more recent common ancestor with chimpanzees than with rhesus monkeys or yeast. The analysis of amino acid sequence homology among different species aids in evaluating their evolutionary relationships. In the same vein, comparing the molecular differences between different categories of organisms, such as mammals, birds, frogs, and fish, reveals their varying degrees of relatedness, implying different times since they shared a common ancestor.
In conclusion, the greater the similarity in amino acid sequences between two organisms, the closer the evolutionary relationship they share. Identifying such similarities is vital in constructing phylogenetic trees and understanding the evolutionary history of life on Earth.