International Society for History, Philosophy, and Social Studies of Biology

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MONDAY, JULY 6  /  19:00 - 20:30  /  Salle Marie Gérin-Lajoie
Phylogenetic Analysis Using a Novel Theoretical Morphospace for Fungi Shows Multiple Origins of Multicellularity Achieved by Multiple Routes

David Crawford** (University of Bristol, United Kingdom)

The project combines a novel theoretical morphospace with a contemporary phylogeny to map origins and routes of multicellularity in fungi. The morphospace decomposes fungal morphology according to numerous characters, some shared with theoretical morphospaces constructed for other groups (e.g., karyokinesis [a]synchronous with cytokinesis, or uni-/multinucleate cells), and some not (e.g., yeast-hyphal dimorphism, or [un]walled hyphal bodies). I discuss the resulting trait map in terms of transitions to multicellularity, transtions in individuality, and hierarchical transition theory more generally. I focus on three major results: (1) The fungi evolved multicellularity multiple times via two different hierarchical transition types - transition via isolation and transition via integration; (2) Many routes to multicellularity in fungi involved losses and/or gains of major morphological characters and sometimes the loss of one form of multicellularity preceding the gain of another form (e.g. routes from filamentous to yeast to filamentous multicellular forms); and (3) The fungi possess remarkable developmental and morphological plasticity that enables lineages to adapt even their basic hierarchical organization to ecological or macroenvironmental changes.