Message - 7th IAL Symposium

2A-1-O
Lichen: from genome to ecosystem in a changing world
2A-1: Graphidaceae: progress in understanding the evolution and diversity of
the largest family of tropical crustose lichens
(2A-1-O1) Submission ID: IAL0178-00001
HISTORICAL BIOGEOGRAPHY, ECOLOGY AND SYSTEMATICS OF THE FAMILY
GRAPHIDACEAE (ASCOMYCOTA: OSTROPALES)
Rivas Plata E. 1
1 Department of Biology, Duke University, Durham, Durham, United States
Graphidaceae is the second largest family of lichenized fungi and the largest family of tropical lichens,
with over 1,500 accepted species. Although the family forms the most important component of tropical lichen
communities, it has only recently begun to be studied in detail. Based on revisionary work undertaken by our
study group for the past ten years, there is now a solid systematic concept in place, with over 50 genera currently
accepted (compared to less than 15 only ten years ago). However, several clades within the family still need
further studies. This applies in particular to the Ocellularia clade, the second largest in the family. The objective
of this study was to study aspects of the natural history of Graphidaceae that go beyond a purely taxonomic
revision. The research is focused on the evolution and early diversification of the family, evolution of phenotypic
characters correlated with environmental parameters and their use for classification, and the phylogeny and
classification of the Ocellularia clade. The results indicate that Graphidaceae evolved and diversified about
160–180 mya in the Jurassic, in accordance with the early evolution of modern tropical rainforests. Many of the
characters used in the delimitation of genera evolved in parallel in unrelated lineages, suggesting ecological constraints
as explanation. Molecular phylogeny of the Ocellularia clade detected several previously unrecognized
lineages deserving generic status, and a formal revised classification is proposed.
(2A-1-O2) Submission ID: IAL0016-00001
DILEMMAS IN SPECIES AND GENUS DELIMITATION IN E.G. GRAPHIDACEAE
Aptroot A. 1
1 ABL Herbarium, Soest, Netherlands
In former days, a species was what the monographer judged a good species, and a genus a handy
group of species. Since cladistics was introduced in taxonomy, genus and species delimitations have become
open to more universal discussions. Especially now that sequences have become available for some species
(albeit still for only a minority of lichen taxa), many new classifications are proposed solely on the prerogative that
a taxon should be monophyletic. This dogma needs closer scrutiny. Taxa evolve, and every monophyletic group
can become paraphyletic the moment that one daughter group becomes geographically or otherwise isolated.
On closer examination, nearly all groups were paraphyletic at least part of their history.
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