AP BIOLOGY

Detailed explanation-1: -Because the DNA sequence determines a protein’s amino acid sequence, a gene shared by two closely related organisms should have similar, or even identical, amino acid sequences. That’s because closely related species most likely diverged from one another fairly recently in the evolutionary span.

Detailed explanation-2: -Homologous genes Biologists often compare the sequences of related genes found in different species (often called homologous or orthologous genes) to figure out how those species are evolutionarily related to one another.

Detailed explanation-3: -Biologists have perfected techniques for determining the sequence of amino acids in proteins. By comparing the amino acid sequences in homologous proteins of similar organisms and of diverse organisms, evolutionary relationships that might otherwise go undetected can be determined.

Detailed explanation-4: -Similar anatomy found in different species may be homologous (shared due to ancestry) or analogous (shared due to similar selective pressures). Molecular similarities provide evidence for the shared ancestry of life. DNA sequence comparisons can show how different species are related.