Ancient diversification of Hyposmocoma moths in Hawaii

Abstract

Island biogeography is fundamental to understanding colonization, speciation and extinction. Remote volcanic archipelagoes represent ideal natural laboratories to study biogeography because they offer a discrete temporal and spatial context for colonization and speciation. The moth genus Hyposmocoma is one of very few lineages that diversified across the entire Hawaiian Archipelago, giving rise to over 400 species, including many restricted to the remote northwestern atolls and pinnacles, remnants of extinct volcanoes. Here, we report that Hyposmocoma is B15 million years old, in contrast with previous studies of the Hawaiian biota, which have suggested that most lineages colonized the archipelago after the emergence of the current high islands (B5 Myr ago). We show that Hyposmocoma has dispersed from the remote Northwestern Hawaiian Islands to the current high islands more than 20 times. The ecological requirements of extant groups of Hyposmocoma provide insights into vanished ecosystems on islands that have long since eroded.