The Rise of Complex Life

The modern world teems with complex life—the animals, plants, fungi, seaweeds, and a dazzling array of single-celled organisms known as the protists. All of these are part of the eukaryotic clade, descended from a common ancestor that lived more than 1 billion years ago. In this talk, I will provide an overview of early eukaryote evolution and the environmental context in which they evolved. I will present new research that sheds light on the habitats in which eukaryotes lived and how they might have survived the extreme “snowball Earth” glaciations that entombed the planet in ice 720–635 million years ago (Ma). Finally, I will highlight the outstanding questions that remain, including what drove their rise to dominance during the late Neoproterozoic Era (~600 Ma).