There are several major classes of "fish". Sharks belong to the cartilaginous class (along with rays and skates). The other major classes are the lobe-fins and the ray-fins. The ray-fin class consists of most of the typical fishy fish that we are familiar with, like salmon, goldfish and tuna. The lobe-fins consist of lungfish and ALL TETRAPODS! That's right, you and I are technically lobe-finned fish.
Also, tuna are more closely related to humans than they are to sharks.
There are several major classes of "fish". Sharks belong to the cartilaginous class (along with rays and skates). The other major classes are the lobe-fins and the ray-fins. The ray-fin class consists of most of the typical fishy fish that we are familiar with, like salmon, goldfish and tuna. The lobe-fins consist of lungfish and ALL TETRAPODS! That's right, you and I are technically lobe-finned fish.
Also, tuna are more closely related to humans than they are to sharks.
Dolphins are lobe-finned fish.
Just thinking about that longass evolutionary journey they took to end up right back to looking like a shark is exhausting!