13.11.2018: Toby SPRIBILLE (Edmonton): Lichen or not: recognizing the Limits of fungal DNA studies in bringing order to complex symbioses. HS 32.01, Institut für Biologie, Bereich für Pflanzenwissenschaften, Holteigasse 6, 17:00 Uhr.
Ever since the recognition that lichens are a chimera of at least two organisms, lichen biologists have disagreed on whether one partner or multiple partners are responsible for coding for the characteristic lichen thallus form of each species. Eventually a rule was adopted bestowing this power solely on the fungus, and tethering the naming of the lichen to that partner alone: the lichen-as-fungus paradigm. The biological evidence to support this was never unequivocal, but a rule was a rule. Now countless name changes are being implemented to retrofit the naming of lichen symbioses to a 68-year-old set of untested assumptions owing to fungal DNA evidence. I will briefly explore three aspects of emerging lichen biology that question the lichen-as-fungus paradigm: first, evidence that lichen symbioses "speciate" faster than their ascomycete fungal components; second, evidence that lichen fungi, like lichen algae, can be promiscuous with respect to the lichens they occur in; and finally, emerging evidence that single-celled microbes are involved in shaping the lichen symbiotic outcomes we traditionally think of as lichen species. Future lichen symbiosis research will have to decide between sticking with an old rule set or asking "what is the biological reason this lichen looks and acts the way it does?"