OEB Special Seminar

Stephanie Pierce
Harvard University, Department of Organismic and Evolutionary Biology

"Major Transitions in Vertebrate Evolution: Perspectives From the Fossil Record"

Abstract: The evolution of the animal tree of life is punctuated by the origin of novel body plans and other adaptations that enabled diversification into new ecological niches. These ‘innovations’ often arise during major evolutionary transitions: events which document the reorganization of one type of animal into something radically different. Living animals can provide important clues about the nature of major transitions; however, the species bridging transitional boundaries are now extinct. Therefore, to accurately reveal how animals have changed from one form to another, I integrate studies of modern animals with a detailed analysis of the fossil record. In this seminar, I will introduce you to two major evolutionary transitions my lab is investigating: 1) the water-to-land transition in tetrapods (four-footed vertebrates), a critical evolutionary event that allowed tetrapods to occupy new ecosystems previously inaccessible to vertebrates; and 2) the reptile-to-mammal transition, which elucidates the evolution of one of the most charismatic groups of animals alive today. Within, I will discuss the questions my lab seeks to answer and the techniques we are using to reanimate the remains of long extinct animals.