Final answer:
Amino acid sequences are compared to construct a phylogenetic tree by evaluating similarities and differences among different species. Computer programs are used to analyze the sequences and estimate evolutionary distances. The resulting tree illustrates the species' relationships based on their amino acid sequences.
Step-by-step explanation:
Amino acid sequences are used to construct a phylogenetic tree by comparing the similarities and differences in the sequences among different species. The more similar the amino acid sequences, the more closely related the species are thought to be. This information is obtained by comparing the sequences of specific genes or proteins of interest using computational tools and databases.
For example, computer programs can align and analyze the amino acid sequences and determine the percentage of sequence identity or homology. Sequence homology can then be used to estimate the evolutionary distance between species and construct the phylogenetic tree. The tree will show the relationships and evolutionary history of the species based on their amino acid sequences.