Zander, Richard H. .
Ancestor-descendant relationships in systematics using virtual fossils.
Ancestor-descendant relationships are being gradually eliminated in phylogenetic classifications by emphasis on sister-group relationships through enforcement of strict holophyly. This includes repositioning, lumping, and splitting of taxa. Some of these taxa are good taxa, and are evolutionarily unique and discordant elements when lumped with a paraphyletic taxon, or they have essentially random diagnoses after splitting (a multiple comparisons problem in statistics) that do not corroborate the split. Paraphyly and heterophyly (phylogenetic nonmonophyly) on molecular trees may imply deep, shared ancestral links between extant taxa. These links are virtual fossils diagnosable at the lowest rank that is inclusive of the exemplars. Examples are given. The now common and unfortunate excision of ancestor-descendant relationships results in a special-purpose classification largely of interest only to phylogeneticists because their methods can only generate sister-group relationships. Modifying classifications according to strict phylogenetic monophyly scrambles a potential source of ancestor-descendant information.
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Evolutionary inferences from non-monophyly on molecular trees.
1 - Missouri Botanical Garden, Po Box 299, St Louis, Missouri, 63166-0299, USA
Presentation Type: Oral Paper:Papers for BSA Sections
Location: Wasatch B/Cliff Lodge - Level C
Date: Wednesday, July 29th, 2009
Time: 1:00 PM