Directors Seminar: The rise of algae in Cryogenian oceans and the emergence of animals

The transition from dominantly bacterial oceans to more complex eukaryotic ecosystems was one of the most profound revolutions in our planet’s history. It changed the distribution of nutrients in the oceans, and dramatically transformed ecosystems. However, we remain oblivious about when this transition occurred.

Jochen will present molecular fossil evidence from a recent Nature paper demonstrating that complex life rose surprisingly late, and that eukaryotic algae conquered the oceans in the hot interlude between the first and second Neoproterozoic Snowball Earth glaciation, 659 Myrs ago. This ‘Rise of Algae’ was responsible for the emergence of our earliest animal ancestors.

Jochen  is a palaeobiogeochemist at the Research School of Earth Sciences, Australian National University. He is fascinated by arcane biological processes in Precambrian oceans, the early evolution of eukaryotes and the emergence of the first animals. To find clues about ancient life, he studies molecular fossils of biological lipids (biomarkers) that can be preserved in sedimentary rocks for billions of years.