Evolutionary biogeography of the terrestrial biota of the Marquesas Islands, one of the world's remotest archipelagos

Abstract

Aim: Here I review phylogenetic studies concerning the biogeography of the Marquesas Islands, an oceanic hotspot archipelago in the Pacific Ocean formed <5.5 Ma, and compare patterns (particularly pertaining to colonization and diversification) within the archipelago to those reported from the Hawaiian and Society Islands. Location: Marquesas Islands, French Polynesia (Pacific Ocean). Methods: I reviewed 37 phylogenetic studies incorporating Marquesas-endemic taxa. I asked the following questions: (a) where are the sister-groups of Marquesas lineages distributed? (b) are Marquesas-endemic “radiations” monophyletic or polyphyletic? (c) what major between-island phylogeographic barriers are seen in the Marquesas? (d) what evidence exists for diversification within islands? (e) how old is the Marquesas biota compared to the archipelago's age? Finally, these patterns are compared with those seen in the Society Islands and Hawaii. Results: Most Marquesan lineages have their closest known relatives on other Pacific plate archipelagos (particularly the Society, Hawaiian, and Austral islands). Most Marquesas-endemic radiations are found to be monophyletic, and among-island diversification appears to be common. There is limited evidence for within-island diversification. Some radiations may be consistent with a weak progression rule in which younger lineages are on younger islands. Crown ages of no Marquesas radiations appear to be older than the age of the archipelago (with one exception). Main conclusions: Diversification of the Marquesas biota resembles that of the Hawaiian Islands more than that of the Society Islands. Many radiations are monophyletic and some appear to diversify in parallel with the formation of the archipelago.