Evolutionary distinctiveness of extant monk seals in light of their extinct relative
In the early 1905s the Caribbean monk seal (Monachus tropicalis) went extinct. The other two species of the same genus live in Hawaii (Hawaiian monk seal, Monachus schauinslandi) and in the Mediterranean and off the coast of NW Africa (Mediterranean monk seal, Monachus monachus). Both are Critically Endangered according to the IUCN. The evolutionary relationships among the three species have remained an open question.
Caribbean monk seal specimen collected in Matanzas, Cuba. (Image: Henry W. Elliott/US National Museum)
In collaboration with the Smithsonian’s National Museum of Natural History and the Leibniz Institute of Zoo and Wildlife Research in Berlin we examined ancient DNA (Cytb gene) and morphology of all three species. Our analyses – published in ZooKeys – showed that the Caribbean monk seal was more closely related to the Hawaiian one rather than the Mediterranean monk seal, thus warranting reclassification of the Caribbean and Hawaiian species into a new genus, Neomonachus. Using fossils to calibrate our phylogenetic estimates we estimated that the Hawaiian and Caribbean species diverged at about 3 to 4 million years ago – around when the Isthmus of Panama separated the Atlantic and Pacific Oceans.