Final answer:
To determine how closely related two animals are by their binomial names, one must consider their genus and species names indicated by the binomial nomenclature system. Animals with the same genus name but different species names are closely related. Evolutionary relationships can be illustrated with a cladogram, which is informed by both morphological and molecular evidence.
Step-by-step explanation:
To determine how closely related two animals are by their binomial name, you must look at the components of the name: the genus and species. The binomial nomenclature system names an organism with these two components, where the genus name is capitalized and comes first, followed by the species name, which is not capitalized. Both parts are typically italicized. For example, Canis lupus is the wolf, and Canis lupus familiaris is the domestic dog, indicating that dogs are a subspecies of wolves and therefore very closely related.
When two animals share the same genus but have different species names, this implies they are related but are different species. For instance, if we have Panthera leo (lion) and Panthera tigris (tiger), they are part of the same genus, Panthera, suggesting they are closely related, more so than to an animal in a different genus, like Ursus arctos (brown bear).
To show evolutionary relationships, a diagram called a cladogram can be used. It illustrates the paths of evolutionary descent from a common ancestor based on morphology and molecular evidence, distinguishing homologous characteristics stemming from a common evolutionary path from analogous characteristics that have evolved independently. This evidence is analyzed using cladistics, applying the principle of maximum parsimony to determine the most straightforward evolutionary path with the least amount of major divergences.