It would most likely render the protein nonfunctional or mis-functional.
The mutation could result in three outcomes:
Silent mutation, which changes the codon to the same amino acid. (AAA->AAG, both are lysine). But since the problem specified that it has a "slightly different amino acid sequence," we can assume this doesn't happen.
Nonsense mutation, which changes a codon to a stop codon. This would end the chain of amino acids, making the protein potentially nonfunctional.
Missense mutation, which changes a codon to another completely different codon. This can be harmful, as in sickle-cell disease, where just one amino acid, glutamic acid, is changed to valine.
The theory of biological evolution explains how organisms evolved during the time. It explains how the characteristics of different species changed over generations. According to the theory, most of current species developed from some distinctly different species that have lived a long time ago.
