Hawaiian Monk Seal - Evolution and Migration

Evolution and Migration

The evolutionary history of the monk seal is controversial, including multiple hypotheses for the phylogenetic to other phocids. Due to the absence of fossil records, little evidence indicates that the Hawaiian monk seal is related to other seals in the family.

Based on its prehistoric and unspecialized skeletal and vascular anatomy, the Hawaiian monk seal is considered the most primitive of living seals and that descends from the Caribbean species, M. tropicalis; all three species originated in the North Atlantic separated from its congeners as early as 15 million years ago.

In an effort to inform the public and conserve the seals, the National Oceanic Atmospheric Administration (NOAA) Fisheries Service developed a historical timeline to demonstrate that the Hawaiian islands has been home to the seals for millions of years and that the seals belong there. Evidence points to monk seals migrating to Hawaii between 4-11 million years ago (mya) through an open water passage between North and South America called the Central American Seaway. The Isthmus of Panama closed the Seaway approximately 3 million years ago.

Berta and Sumich ask how this species came to the Hawaiian Islands when its closest relatives are on the other side of the world in the North Atlantic and Mediterranean Sea. No one knows whether the Hawaiian is the oldest or the youngest seal in the Monachus genus. The species may have evolved in the Pacific or Atlantic, but in either case, came to Hawaii long before the first Polynesians.