September
Earth’s Living Treasures: Going, Going, … Gone?
Floyd Sandford, Professor Emeritus of Biology
September 4
It has been called the quiet crisis: the dramatic increase in the extinction of living things in modern times. Extinction is a consequence of the inability of living species to adapt to ever- changing conditions on our planet. Scientists estimate that over the last 3.5 billion years 95 to 99 percent of all species that once existed have become extinct, many of them perishing in five mass extinction events caused by natural phenomena like asteroid impacts, extreme temperature changes, rising or falling sea levels or widespread volcanic activity. While extinction as a natural ongoing process may be the ultimate fate of all species, the dramatic increases in extinction rates in recent times — a mere geological blink of an eye — can be traced to the activities of a single species: humans. This one-week forum presented by Professor Emeritus of Biology Floyd Sandford will consider how humans are contributing to the impoverishment of earth’s biodiversity in a human-influenced sixth mass extinction. Though life forms from plants to insects to amphibians are being impacted, this forum will focus on the quiet crisis among mammals —the species with which humans have the most in common.
Dinosaurs: What We Think We Know and Why
Jon Mitchell, Assistant Professor of Biology
September 11, 18, 25, and October 2
This four-week forum presented by Assistant Professor of Biology Jon Mitchell will highlight the science, mystery, meaning and beauty of dinosaurs. It will explore what we know about when, where and how dinosaurs lived their lives. The first session will introduce the basics of how we find and study dinosaur fossils, including some basic background in geology and how the study of geology has influenced larger historical events like the Industrial Revolution and the Cold War. As part of the presentation, Dr. Mitchell will share his experiences digging dinosaur fossils in unusual places. Week two will focus on dinosaur evolution. We will survey the different kinds of dinosaurs, what they looked like, and how they changed over time. This will involve an introduction to phylogenetics, which is the science underlying how we reconstruct the “tree of life” and how related animals are to one another. In week three, we will examine what we do and do not know about what different dinosaurs ate and how they lived. We will see how scientists variously use fossilized dinosaur dung, organs, footprints, isotopes and other strange and unexpected pieces of evidence to test their conclusions about dinosaur lifestyles. The final session will discuss trends and patterns in the fossil record of dinosaurs and what they tell us about the processes of evolution in general and dinosaurs in particular.