West Indian manatees are large aquatic mammals that live in rivers and near shore estuaries, especially in Florida. They have two flexible front flippers with three or four toenails, similar to elephant toenails. Though they lack hind limbs, manatees have vestigial pelvic bones, as shown in the diagram.
Manatee and elephant skeletons are shown side-by-side. The manatee, an aquatic animal, has a skeleton that has two large front limbs and two very tiny hind limb bones that do not form actual limbs. The elephant has four large limbs.
Which of the following answer choices best describes how evidence of the manatee toenails and pelvic bones supports the scientific theory of evolution of these animals?
The fact that manatees and elephants have toenails and pelvic bones suggests that their limbs evolved for similar use in similar environments.
The fact that manatees lack hind legs, unlike elephants, suggests that manatees and elephants evolved toenails in parallel without any common ancestry.
The existence of pelvic bones and toenails in manatees and elephants suggests that manatees and elephants evolved from the same land animal.
The existence of pelvic bones and toenails in manatees and elephants suggests that these animals are evolving into similar animals.