|
|
||||||||
Population Biology |
2Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts 02138 USA; 3Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, Colorado 80309 USA
ABSTRACT
Climate change during the Quaternary played an important role in the differentiation and evolution of plants. A prevailing hypothesis is that alpine and arctic species survived glacial periods in refugia at the periphery of glaciers. Though the Rocky Mountains, south of the southernmost extent of continental ice, served as an important glacial refuge, little is known about how climate cycles influenced populations within this region. We inferred the phylogeography of Sedum lanceolatum (Crassulaceae) within the Rocky Mountain refugium to assess how this high-elevation plant responded to glacial cycles. We sequenced 884 base pairs (bp) of cpDNA intergenic spacers (tRNA-L to tRNA-F and tRNA-S to tRNA-G) for 333 individuals from 18 alpine populations. Our highly variable markers allowed us to infer that populations persisted across the latitudinal range throughout the climate cycles, exhibited significant genetic structure, and experienced cycles of range expansion and fragmentation. Genetic differentiation in S. lanceolatum was most likely a product of short-distance elevational migration in response to climate change, low seed dispersal, and vegetative reproduction. To the extent that Sedum is a good model system, paleoclimatic cycles were probably a major factor preserving genetic variation and promoting divergence in high-elevation flora of the Rocky Mountains.
Key Words: alpine climate cycles cpDNA Crassulaceae genetic diversity historical biogeography Quaternary Rocky Mountain refuge Sedum lanceolatum
This article has been cited by other articles:
![]() |
T. Barbara, G. Martinelli, C. Palma-Silva, M. F. Fay, S. Mayo, and C. Lexer Genetic relationships and variation in reproductive strategies in four closely related bromeliads adapted to neotropical 'inselbergs': Alcantarea glaziouana, A. regina, A. geniculata and A. imperialis (Bromeliaceae) Ann. Bot., January 1, 2009; 103(1): 65 - 77. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Tian, L.-C. Luo, S. Ge, and Z.-Y. Zhang Clear Genetic Structure of Pinus kwangtungensis (Pinaceae) Revealed by a Plastid DNA Fragment with a Novel Minisatellite Ann. Bot., July 1, 2008; 102(1): 69 - 78. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. Marlowe and L. Hufford Evolution of Synthyris sect. Dissecta (Plantaginaceae) on sky islands in the Northern Rocky Mountains Am. J. Botany, March 1, 2008; 95(3): 381 - 392. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. Gaudeul, H. K. Stenoien, and J. Agren Landscape structure, clonal propagation, and genetic diversity in Scandinavian populations of Arabidopsis lyrata (Brassicaceae) Am. J. Botany, July 1, 2007; 94(7): 1146 - 1155. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |