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Montane refugia predict population genetic structure in the L arge‐blotched E nsatina salamander
Author(s) -
Devitt Thomas J.,
Devitt Susan E. Cameron,
Hollingsworth Bradford D.,
McGuire Jimmy A.,
Moritz Craig
Publication year - 2013
Publication title -
molecular ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.619
H-Index - 225
eISSN - 1365-294X
pISSN - 0962-1083
DOI - 10.1111/mec.12196
Subject(s) - refugium (fishkeeping) , biology , ecology , range (aeronautics) , population , disjunct , phylogeography , genetic structure , disjunct distribution , evolutionary biology , salamandra , salamander , habitat , genetic variation , phylogenetics , phylogenetic tree , genetics , gene , materials science , demography , sociology , composite material
Understanding the biotic consequences of P leistocene range shifts and fragmentation remains a fundamental goal in historical biogeography and evolutionary biology. Here, we combine species distribution models ( SDM ) from the present and two late Q uaternary time periods with multilocus genetic data (mitochondrial DNA and microsatellites) to evaluate the effect of climate‐induced habitat shifts on population genetic structure in the L arge‐blotched E nsatina ( E nsatina eschscholtzii klauberi ), a plethodontid salamander endemic to middle and high‐elevation conifer forest in the T ransverse and P eninsular R anges of southern C alifornia and northern B aja C alifornia. A composite SDM representing the range through time predicts two disjunct refugia, one in southern C alifornia encompassing the core of the species range and the other in the S ierra S an P edro M ártir of northern B aja C alifornia at the southern limit of the species range. Based on our spatial model, we would expect a pattern of high connectivity among populations within the northern refugium and, conversely, a pattern of isolation due to long‐term persistence of the S ierra S an P edro M ártir population. Our genetic results are consistent with these predictions based on the hypothetical refugia in that (i) historical measures of population connectivity among stable areas are correlated with gene flow estimates; and (ii) there is strong geographical structure between separate refugia. These results provide evidence for the role of recent climatic change in shaping patterns of population persistence and connectivity within the Transverse and Peninsular Ranges, an evolutionary hotspot.