Baby Seal, Lake Baikal, Siberia, Russia

Sexual coercion is common among pinnipeds, even on other species. In one videotaped incident, a 100 kilograms (220 lb) Antarctic fur seal pinned down a 15 kilograms (33 lb) king penguin and attempted to mount it for about 45 minutes.
Evolution
Recent molecular evidence suggests that pinnipeds evolved from a bearlike ancestor about 23 million years ago during the late Oligocene or early Miocene epochs, a transitional period between the warmer Paleogene and cooler Neogene period. The earliest fossil Pinniped that has been found is Puijila darwini, of about 23 million years ago. Pujilla had heavy limbs, indicative of upright movement on land, and flattened phalanges, indicating that they were probably webbed, but not yet flippers. The discovery of Pujilla in northern Canada strongly suggests that pinnipeds originated in the Arctic. The reference to Charles Darwin is in honor of his contention made in On the Origin of Species (1859) that