Final answer:
Species that share a more recent common ancestor and have a higher percentage of DNA similarity are considered more closely related, and this information can typically be visualized on a phylogenetic tree.
Step-by-step explanation:
Organisms that are most closely related usually share a higher percentage of DNA, which translates into more common characteristics. When analyzing a phylogenetic tree, we can determine relationships between species by looking at the points where their lineage branches merge. For example, if species 1 and 2 have a more recent common ancestor than either does with species 3, this suggests that species 1 and 2 are more closely related. Similarly, in a table showing DNA similarity percentages, the organism with the highest percentage of DNA similarity to humans would be considered our closest living relative among the listed species. In the context of phylogenetic relationships, the species with the most common characteristics would likely share more genetic similarities and therefore have more recent common ancestors, just as shown in figures where appendage construction indicates common ancestry among several organisms.