Intercontinental Correlation of Geographical Ranges Suggests Stasis in Ecological Traits of Relict Genera of Temperate Perennial Herbs
Abstract
Disjunct taxa within genera of herbaceous perennial plants relict to temperate eastern Asia and eastern North America exhibit a significant correlation in area of geographical range. This relationship suggests evolutionary stasis of traits related to ecological distribution over periods of at least 10 million and possibly more than 30 million yr. Because woody taxa lack this pattern but appear to exhibit broader ecological distributions on a local scale than do herbaceous taxa, we suggest that stasis goes hand in hand with ecological specialization; some restricted subsets of ecological conditions to which herbs are specialized may persist within a changing ecological mosaic.




