DeVore, Melanie L. , Pigg, Kathleen B. .
The value of fossils for tracking a family's spatial history: an underrated tool?
There have been numerous studies addressing the value of fossils as an independent means to date the divergence time of clades but less attention has been paid to how fossils can be used in phylogenetically based biogeographic methods. Some biogeographic techniques such as ancestral areas and DIVA have been developed using distributional data from only extant taxa. Whether these techniques can reproduce accurately the biogeographic history of taxa is worth exploring. Not only can the fossil record be used to estimate a taxon's spatial history, but it is also possible to document specific ecosystems (e.g. mangroves). However, researchers sometimes place confidence in fossils to date nodes for a given family, yet overlook their value for describing the family's spatial history. For example, definitive records of the Meliacaeae have been documented in North America, Europe and Asia. Yet, biogeographic studies based only on extant members of the family suggest that it originated and diversified in Africa. Another example, in the Rhizophoraceae, Tribe Rhizophoreae, indicates that the basal clade containing Bruguiera has an extant distribution in tropical Africa, Australia, South Asia and tropical Pacific regions. However, its fossil record, which is often overlooked, includes occurrences in the lower Eocene of France, Upper Eocene of England, Oligocene of Isle of Wight and middle Miocene of Japan and the Pacific Islands. While DIVA and ancestral areas may be used with more confidence when working with taxa that have appeared relatively recently or at lower taxonomic levels, they may produce questionable results when working with older taxa at higher taxonomic levels. Clearly biogeographical studies will benefit from clear communication from systematists working with both extant and fossil taxa.
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1 - Georgia College & State University, Biological & Environmental Sciences, 135 Herty Hall, Campus Box 81, Milledgeville, Georgia, 31061, USA
2 - Arizona State University, School of Life Sciences, P.O. Box 874501, Tempe, Arizona, 85287-4501, USA
Presentation Type: Oral Paper:Papers for Topics
Location: Boulevard B/Hilton
Date: Monday, July 9th, 2007
Time: 10:15 AM