Humans, lobe-finned fish, frogs, bats, and alligators are all vertebrates, meaning they have a backbone. However, humans and lobe-finned fish are more closely related to each other than they are to frogs, bats, or alligators. This is because humans and lobe-finned fish both have fleshy fins, while frogs, bats, and alligators have bony fins. Additionally, the bones in the skulls of humans and lobe-finned fish are more similar to each other than they are to the bones in the skulls of frogs, bats, or alligators.