Chemical and Anatomical similarities

• Biological molecules: Closely related species contain similar molecules, less closely related organisms have more distinct molecules; comparison of amino acids in Cytochrome C (essential for aerobic respiration) reveals evolutionary relationships - Cyt C changes reflect when species' separated from common ancestor also increased subunits in higher organisms improve DNA and RNA polymerase improved enzyme regulation
• DNA: The sequences of bases in genes can be compared; more distantly related species have more differences in their DNA and closely related species have very similar DNA, for humans: 1.2% different coding DNA to chimpanzees, 1.6 % to gorillas and 6.6% to baboons