Liu, Yang , Budke, Jessica , Goffinet, Bernard .
Phylogenetic inference rejects sporophyte-based classification of the Funariaceae (Bryophyta): a rapid radiation suggests rampant homoplasy in sporophyte evolution.
The Funariaceae, which include the model organisms Physcomitrella patens and Funaria hygrometrica, comprise 15 genera, three of which accommodate approximately 95% of the 250-400 species. Historically, generic concepts are based on the morphological complexity of the moss sporophyte. The boundary between two of the major genera, Entosthodon and Funaria, has fluctuated with authors emphasizing alternate diagnostic characters. We sampled ten loci across the three genomic compartments to reconstruct the relationships within the Funariaceae and assess whether supraspecific taxa defined by traits of the sporophyte represented monophyletic lineages.
The sporophyte-based circumscription of two of the speciose genera of the Funariaceae is rejected. Entosthodon and Physcomitrium,as well as some of their subgenera, are resolved as polyphyletic, and even the three species of Physcomitrella are confirmed to have diverged from distinct ancestors. By contrast, exemplars of Funaria,that are morphologically diagnosed by a compound annulus, comprise a single clade. Each of these hypotheses is robust, withstanding a series of tests formonophyly of the genera.
These observations suggest that sporophytic features alone, often considered to bemore conserved and hence phylogenetically more informative than vegetative traits can also be highly homoplastic. Within the Funariaceae, none of the novel clades seem a priori to be defined by a uniquely derived character state, when considering the characters historically used to distinguish lineages. The core clade of the Funariaceae (i.e., Funarioideae minus Funaria),which may ultimately include much of the species diversity, is estimated to have diversified rapidly in the Miocene. The combination of polyphyly of supraspecific taxa defined by sporophytic traits, rampant homoplasy of these traits and the rapid radiation of the core Funariaceae, reveals that characters of the sporophyte, such as the peristome architecture, length of the seta, and symmetry of the capsule are phylogenetically labile and that the genetic networks underlying their expression may have been under a rather loose control.
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1 - University Of Connecticut, Ecology & Evolutionary Biology, 75 North Eagleville Road, Storrs, CT, 06269-3043, USA
2 - University Of Connecticut, Department Of Ecology & Evolutionary Biology, 75 N. Eagleville Rd. U-3043, Storrs, CT, 06269, USA
3 - University Of Connecticut, Department Of Ecology & Evolutionary Biology, 75 N. Eagleville Road, U-3043, STORRS, CT, 06269-3043, USA
Presentation Type: Oral Paper:Papers for Sections
Location: Lindell B/Chase Park Plaza
Date: Monday, July 11th, 2011
Time: 8:45 AM