Message - 7th IAL Symposium

The 7 th International Association for Lichenology Symposium 2012
(2I-O8) Submission ID: IAL0277-00001
GOOD-BYE MORPHOLOGY, OR THREE CHEERS FOR NUANCE? MOLECULAR
PHYLOGENETICS AND A POSTERIORI MORPHOLOGICAL ANALYSIS
IN TWO CRUSTOSE LICHEN GENERA
Spribille T. 1 , Grube M. 2
1 Division of Biological Sciences, University of Montana, Missoula, Montana, United States
2 Institute of Plant Sciences, University of Graz, Graz, Austria
Recent advances in molecular phylogenetic analyses of lichen mycobionts have revealed that many
taxa traditionally assumed to represent single, widespread species in fact consist of multiple, genetically distinct
lineages. Consistent with a current popular trend across biological disciplines, these have been interpreted by
many authors as “cryptic species”. While some authors have highlighted the usefulness of molecular markers for
elucidating relationships in morphologically subtle groups, others suggest that the morphological approach itself
is problematic and leading lichenologists potentially to overlook large nodes of diversity. Detection of diagnostic
signal in a morphological character set requires systematic testing of congruence of a wide range of traits with
identified clades. In molecular studies of mycobionts in two morphology-poor crust lichen genera, Mycoblastus
and Xylographa, we recently detected numerous previously overlooked monophyletic groups that by most
current measures would be called cryptic species. In some cases our results quadruple or quintuple the number
of species relative to classical concepts. We tested the null hypothesis of no congruence between phenotype
and genotype by scoring traditional and non-traditional morphological and chemical traits against the resulting
molecular clades. In both genera, we found nearly all lineages could be reliably recognized using phenotypic
characters alone. Far from being problematic, reliance on morphology underlies nearly all hypothesis-testing in
current lichen molecular phylogenetics from the proposal stage to final publication. Molecular phylogeneticists
have a unique opportunity to support and be supported by field lichenologists in ongoing efforts to elucidate
specific problems such as photobiont effects on morphology and convergent body plan evolution in symbiosis.
Together they can make meaningful contributions to lichen conservation that go well beyond the lab bench.
27
2I-O