ibclogo XVI International Botanical Congess


Abstract Number: 3661
Session = 8.6.4


CLIMATE OSCILLATIONS, ANCIENT HABITAT FRAGMENTATION, AND GENETIC BOTTLENECKS IN AN ARBORESCENT AMAZONIAN HERB


W.J. Kress and Preston R. Aldrich (Botany-NMNH, Smithsonian Institution, Washington, DC 20560-0166 USA)


The Amazon basin, containing the largest continuous tract of rain forest on the planet, is not a static, unchanging entity. Over the past million years the forests have experienced numerous cycles of contraction and expansion in conjunction with climatic oscillations due to ice ages and intervening warm periods. We present evidence using genetic markers that the pan-Amazonian herb Phenakospermum guyannense (Strelitziaceae) has experienced repeated population bottlenecks as a result of these fluctuations in forest distribution due to global climate change. These observations provide insights on gene diversification in this species and more generally on the role that habitat fragmentation and climate change play in the maintenance of genetic and species diversity in the tropics.


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