Th. Heaton et al., AN ICE-AGE REFUGIUM FOR LARGE MAMMALS IN THE ALEXANDER ARCHIPELAGO, SOUTHEASTERN ALASKA, Quaternary research, 46(2), 1996, pp. 186-192
Genetic and paleontological evidence are combining to provide a new an
d surprising picture of mammalian biogeography in southeastern Alaska.
Prior to our study, the brown and black bears of the Alexander Archip
elago were considered postglacial immigrants that never had overlappin
g ranges. Vertebrate fossils from caves on Prince of Wales Island now
demonstrate that brown and black bears coexisted there (and even inhab
ited the same caves) both before and after the last glaciation. Differ
ences in mtDNA sequences suggest that living brown bears of the Alexan
der Archipelago comprise a distinct clade and are more closely related
to polar bears than to their mainland conspecifics. We conclude that
brown bears, and perhaps other large mammals, have continuously inhabi
ted the archipelago for at least 40,000 yr and that habitable refugia
were therefore available throughout the last glaciation. (C) 1996 Univ
ersity of Washington.