Land BridgesAncient Environments, Plant Migrations, and New World Connections

Land BridgesAncient Environments, Plant Migrations, and New World Connections

Alan Graham

Print publication date: 2018

ISBN: 9780226544151

Publisher: University of Chicago Press

Abstract

The New World has been connected to and separated from distant lands by five land bridges that during the late Cretaceous and Cenozoic periodically served as barriers and pathways for migration: the Bering Land Bridge, the North Atlantic Land Bridge, the Antillean Land Bridge, the Central American Land Bridge, and the Magellan Land Bridge. New World land bridges constitute an important means whereby organisms interchanged and separated from those of adjacent lands explaining some widespread similarities and disjunct distributions (e.g., between eastern Asia and eastern North America). Other factors in addition to physiographic and climatic conditions through time include former (early) positions of continents, edaphic features of the target and source areas, pathogens, pollinators, and the distribution potential of the propagules allowing for dispersal over, around, and through the connections (e.g., by birds, migrating land animals, wind, and marine currents). Understanding the complexity of past and present distributions (e.g., of plants) requires a comprehensive array of methods with results interpreted within the broadest context of geological, climatological, and biological (faunal) information for adequate explanation.