Biologist can compare amino-acid sequence of the same protein from two or more species sequences can be very similar or very different what do the similarities and differences tell us?
Similarities in amino acid sequences tell us the the genes coding for these proteins are similar. Similar genes are due to shared ancestry ie the organisms have evolved from a… common ancestor in the past. Differences in amino acid sequence tell us that mutations have occurred in the genes since the organisms separated from the common ancestor. The bigger the differences, the longer the organisms have been separated. (MORE)