Bringing Together the Living and Dead: Integrating Extant and Fossil Biodiversity in Evolutionary Studies
Hermsen, E. J. .
Elucidating the diversification of saxifragalean lineages through simultaneous analysis including extant and fossil taxa.
OVER a decade ago, the first simultaneous analysis including both extant and fossil taxa was published. While this technique has yet to become pervasive, its use is becoming more widespread as an approach to placing fossil representatives in a phylogenetic context within clades including extant taxa, especially within those groups that have a significant representation in the Recent. The angiosperm order Saxifragales is particularly suited to this type of approach for several reasons: 1) the group has undergone major and unexpected rearrangements since the advent of molecular phylogenetics, 2) molecular sequence data have been collected for many taxa within the order, and 3) much morphological and anatomical research has been published on various lineages within Saxifragales. While Saxifragales has a significant fossil record, few fossil taxa within the order are based on both vegetative and reproductive organs, meaning that in most instances there are few morphological characters available to place each individual fossil taxon in a phylogenetic context. However, this problem can be overcome through the use of simultaneous analysis, where the overwhelming numbers of molecular sequence data can become the primary determinants of relationships among extant taxa, helping to buffer the resultant trees against instability due to inclusion of fossil taxa with large amounts of missing data. While not a panacea, when this approach is successful, it allows for better resolution of the phylogenetic positions of fossil among extant taxa and for better prediction of the sequence and timing of character evolution. This study will explore both the benefits and limitations of the simultaneous analysis approach with specific reference Saxifragales, including Cretaceous, Tertiary, and Recent taxa within the order.
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1 - University of Kansas, Ecology and Evolutionary Biology, Haworth Hall, 1200 Sunnyside Avenue, Lawrence, Kansas, 66045-7534, USA
Presentation Type: Symposium or Colloquium Presentation
Location: 134/Performing Arts Center
Date: Tuesday, August 1st, 2006
Time: 2:30 PM