<p><strong>Fig. 1.16.</strong> This phylogenetic tree of life shows the three domains, which make up all of life on Earth. The length of the branches on phylogenetic trees represents evolutionary time.</p>

Fig. 1.16. This phylogenetic tree of life shows the three domains, which make up all of life on Earth. The length of the branches on phylogenetic trees represents evolutionary time.

Image courtesy of National Aeronautics and Space Administration (NASA) and Eric Gaba, Wikimedia Commons