Final answer:
The kingdom Animalia exhibits the greatest biodiversity among insects, as they have evolved to fit various ecological niches and represent the majority of species within the kingdom. Mammals and other vertebrates, though often highlighted in media, make up a small portion of total biodiversity.
Step-by-step explanation:
In the kingdom Animalia, the most biodiversity is found among insects. This is primarily because insects have adapted to a wide variety of environments and have undergone extensive speciation. If we look at a phylogenetic tree, the domain of Plantae is not included, thereby confirming that plants are not part of the kingdom Animalia. In a biodiversity hotspot, we can expect to find a large number of endemic species.
Animalia encompasses a range of organisms from ants to whales, including diverse groups such as arthropods, fish, amphibians, reptiles, and mammals. It is important to note that mammals, while often featured in media such as National Geographic, represent a small fraction of animal biodiversity. Nearly 97 percent of the animal kingdom consists of invertebrates which lack a cranium and a spinal column. Hence, focusing on vertebrates would give a skewed perspective of animal diversity.