Why Whales Got So Big
It’s often said that the ocean releases them from the constraints of life on land. It’s actually the opposite.
The first time I came face to face with a sea lion, I nearly screamed. I was snorkeling, and after a long time spent staring down at colorful corals, I looked up to see a gigantic bull, a couple of feet in front of my mask. Its eyes were opalescent. Its long canines hinted at its close evolutionary ties to land-based predators like bears and dogs. And most unnervingly of all, it was huge.
Mammals tend to get that way when they invade the ocean. The pinnipeds—seals, sea lions, and walruses—tend to be immense blobs of muscle
