June

Talk Title: The origin of coral symbiosis: the skeletal record

Dr Jarosław Stolarski

Date: Wednesday, 07.06.2017 , 13:00, Cent Lecture Theatre 0142

Institute of Paleobiology, Polish Academy of Sciences, Warsaw, Poland.

Abstract.

The coral-algal symbiosis is an iconic example of mutualistic interactions between two organisms in which each derives benefits: the zooxanthellae (dinoflagellate algae) provide most/all the energy needs of the coral host metabolism, enhance nitrogen recycling and calcification. In return, the coral provides the zooxanthellae with nutrients and with rather stable (protected from predation) living conditions. Symbiosis is recognized as crucial for the success of today’s reefs and explains an old Darwin’s paradox about the flourishing of the coral reefs in nutrient poor (oligotrophic) environments. However, it is not well understood how the symbiosis started in ancient corals, whether these were dinoflagellate algae that were symbiotic partners, was the symbiosis established one time only or independently, several times in coral history, and what was the (paleo)environmental context of this evolutionary event? In this talk I will explore those aspects of the symbiotic relationships that can be interpreted from the mineral skeleton that only can be found in the coral fossil record. Lessons from the geological past provide fascinating insight into how important and resistant was symbiosis for corals that across millions of years experienced major fluctuations in temperatures and dramatic changes of ocean geochemistry.