The elephant seal nomenclature is arbitrary, based on fallacies, and is impractical. Elephant seals are true seals that originated in the North Atlantic 15 to 20 million years ago. Today, the northern species is found along the west coast of North America and the southern species inhabits sites around the Antarctic continent. The two species have been separated for a minimum of 5,000 years but the exact duration is unclear. The northern elephant seal population was abundant before the seals were hunted for their blubber oil in the first half of the nineteenth century. The slaughter was so extensive and relentless that by the late-nineteenth century, the species was considered extinct. Approximately 20 individuals survived, however, on a volcanic island in Mexico. The population experienced a severe population bottleneck and lost genetic diversity. The southern species was also hunted by sealers, but its population was not reduced as drastically.