Bryological and Lichenological Section/ABLS
Forrest, Laura L. , Long, David G. , Hollingsworth, Michelle L. , Villarreal A., Juan Carlos , Clark, Alexandra , Tosh, James , Hollingsworth, Pete .
Into the Tropics: a brief history of complex thalloid liverworts.
Evidence from a range of organisms suggests that the tropics are neither exclusively museum for, nor cradle of, biodiversity, but instead act as both: taxa originate in the tropics and expand out toward the poles (tropics as cradle) while still maintaining a tropical presence (tropics as museum) (Jablonski, Roy & Valentine 2006, Science 102-106). But how far back in the tree of life does this general pattern hold true? Although controversy remains as to which extant land plant lineage was the first to diverge, phylogenetic and palaeontological data agree that liverworts are a very ancient group, and that their major lineages may have evolved on a very different world (e.g. lacking soils and trees). A phylogeny for 87 accessions of complex thalloid liverworts generated from DNA sequence data from 1 nuclear, 2 mitochondrial and 8 chloroplast loci (total aligned characters included in the analyses: 10,930; parsimony informative characters: 2,757) was used to investigate plantsí present-day habitats. Liverworts with predominantly tropical habitats (e.g. Cyathodium, Monoclea, Dumoritera) are always derived from non-tropical lineages, while many of the earlier-diverging liverwort lineages contain weedy plants of marginal or ephemeral habitats (e.g. Lunularia, Blasia, Sphaerocarpos). Are these modern habitat preferences indicative of the type of habitat that was available when these lineages first evolved? We are in the process of generating a dated molecular phylogeny that may allow us to answer this question.
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1 - University of Connecticut, Ecology and Evolutionary Biology, 75 N. Eagleville Rd., Storrs, CT, 06269-3043, USA
2 - Royal Botanic Garden Edinburgh, 20A Inverleith Row, Edinburgh, Scotland, EH3 5LR, United Kingdom
Presentation Type: Oral Paper:Papers for Sections
Location: 554A/Convention Center
Date: Monday, August 2nd, 2010
Time: 3:30 PM