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Range persistence during the last glacial maximum: Carex macrocephala was not restricted to glacial refugia
Author(s) -
KING MATTHEW G.,
HORNING MATTHEW E.,
ROALSON ERIC H.
Publication year - 2009
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/j.1365-294x.2009.04280.x
Subject(s) - glacial period , biology , last glacial maximum , refugium (fishkeeping) , ecology , population , range (aeronautics) , biological dispersal , paleontology , habitat , materials science , demography , composite material , sociology
The distribution of many species inhabiting northwestern North America has been heavily influenced by the climatic changes during the late Pleistocene. Several studies have suggested that species were restricted to glacial refugia north and/or south of the continental ice sheet front. It is also hypothesized that the coast of northwestern North America could have been a prime location for glacial refugia because of the lowering of the eustatic sea level and the concomitant rise of the continental shelf because of tectonic rebound. Alternatively, some coastal species distributions and demographics may have been unaffected in the long‐term by the last glacial maximum (LGM). We tested the glacial refugium hypothesis on an obligate coastal plant species, Carex macrocephala by sampling 600 individuals from 41 populations with 11 nuclear microsatellite loci and the rpL16 plastid intragenic spacer region. The microsatellite data sets suggest a low level of population differentiation with a standardized G ′ ST = 0.032 and inbreeding was high with an F = 0.969. The homogenization of the populations along the coast was supported by a principal coordinate analysis, amova s and samova analyses. Analyses using the rpL16 data set support the results of the microsatellite analyses, with a low F ST of 0.042. Coalescent and mismatch analyses using rpL16 suggest that C. macrocephala has not gone through a significant bottleneck within the past 100 000 years, although a much earlier population expansion was indicated by the mismatch analysis. Carex macrocephala exhibits the characteristics of metapopulation dynamics and on the basis of these results, we concluded that it was not restricted to glacial refugia during the LGM, but that it existed as a large metapopulation.