Final answer:
The tiger is most closely related to the lion, leopard, and jaguar, all members of the genus Panthera, which reflects their close evolutionary relationship based on physical features and genetic similarities.
Step-by-step explanation:
The tiger, scientifically known as Panthera tigris, is most closely related to three other members of the genus Panthera: the lion (Panthera leo), the leopard (Panthera pardus), and the jaguar (Panthera onca). These species share a common ancestor and belong to the family Felidae, commonly known as the cat family. Within this family, the genus Panthera represents some of the largest and most iconic cats that exhibit similarities in their physical features, vocalizations, and other behavioral aspects which reflect their close evolutionary relationships.
Scientists classify organisms by their physical features and genetic relationships, revealing the evolutionary history and common ancestry of species like the tiger and its closest relatives. Classifying organisms based on evolutionary principles allows us to understand the species over time and how they have adapted and diversified from their common ancestors.