title: Parallel responses of bees to Pleistocene climate change in three isolated archipelagos of the southwestern Pacific.
abstract: The impacts of glacial cycles on the geographical distribution and size of populations have been explored for numerous terrestrial and marine taxa. However, most studies have focused on high latitudes, with only a few focused on the response of biota to the last glacial maximum (LGM) in equatorial regions. Here, we examine how population sizes of key bee fauna in the southwest Pacific archipelagos of Fiji, Vanuatu and Samoa have fluctuated over the Quaternary. We show that all three island faunas suffered massive population declines, roughly corresponding in time to the LGM, followed by rapid expansion post-LGM. Our data therefore suggest that Pleistocene climate change has had major impacts across a very broad tropical region. While other studies indicate widespread Holarctic effects of the LGM, our data suggest a much wider range of latitudes, extending to the tropics, where these climate change repercussions were important. As key pollinators, the inferred changes in these bee faunas may have been critical in the development of the diverse Pacific island flora. The magnitude of these responses indicates future climate change scenarios may have alarming consequences for Pacific island systems involving pollinator-dependent plant communities and agricultural crops.
authors.affiliation: School of Biological Sciences, Flinders University, , GPO Box 2100, Adelaide, South Australia 5001, Australia, South Australian Museum, , GPO Box 234, Adelaide, South Australia 5000, Australia, School of Pharmacy and Medical Sciences, University of South Australia, , Adelaide, South Australia 5000, Australia.
authors.forename: Scott V C
authors.initials: SV
authors.lastname: Groom
authors.forename: Mark I
authors.initials: MI
authors.lastname: Stevens
authors.forename: Michael P
authors.initials: MP
authors.lastname: Schwarz
mesh_terms: D000818:Animals; D001516:Bees / Q000235:genetics / Q000502:physiology*; D057231:Climate Change; D003576:Electron Transport Complex IV / Q000235:genetics; D005367:Fiji; D019476:Insect Proteins / Q000235:genetics; D024101:Mitochondrial Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D011156:Population Density; D018947:Samoa; D017422:Sequence Analysis, DNA; D009514:Vanuatu
chemical_list: D019476:Insect Proteins; D024101:Mitochondrial Proteins; D003576:Electron Transport Complex IV
keywords: Fiji; Lasioglossum (Homalictus); Samoa; Vanuatu; halictine bees; last glacial maximum