Keynyn Brysse: Evidence, interpretation, and communication: Lessons from the interdisciplinary mass extinction debates

The Science Technology and Society Program at the University of Alberta is pleased to present:
Keynyn Brysse, Postdostoral Research Associate, Princeton University
Evidence, interpretation, and communication: Lessons from the interdisciplinary mass extinction debates
Wednesday, October 19, 3:00, Tory Building 8-22

On June 6, 1980, an article entitled “Extraterrestrial cause for the Cretaceous-Tertiary extinction: experimental results and theoretical interpretation” was published in Science. Its authors – physicist Luis Alvarez, his son, geologist Walter Alvarez, and nuclear chemists Frank Asaro and Helen Michel – presented evidence that an asteroid or comet had hit the Earth 65 million years ago, and argued that it caused the mass extinction known to have occurred at that time.

Scientists of many fields embraced the Alvarez impact hypothesis and began searching for further physical evidence of the impact. Some scientists argued that the physical evidence suggested a volcanic eruption instead of an impact, whereas others (primarily vertebrate paleontologists) argued that the biological evidence points to neither volcanism nor an impact as the (sole) cause of the K-T mass extinction. Vertebrate paleontologists had several sound scientific reasons for skepticism, including fossil evidence documenting a pattern of victims and survivors more complex than could be explained by either impact or volcanism. Paleontologists also resented the intrusion into their domain by disciplinary outsiders who did not appreciate the complexity of the fossil record and the pattern of the history of life.

I have identified several sources of communication problems in this debate between experimental scientists (including the Alvarez team) and historical scientists (such as paleontologists). In my talk I will explore these problems and their implications, including different ways of framing research questions, and differing ideas regarding what counts as relevant evidence in answering questions about the K-T extinction.  The debate over the cause(s) of the K-T and other mass extinctions forms a rich case study of interdisciplinary scientific debate, in which not only the answers, but the standards of evidence, and even the questions that can and should be asked, are shifting and contested territories.


Keynyn Brysse is a historian of paleontology. She holds a B.Sc. in Honors Paleontology and an M.A. in History from the University of Alberta, and a Ph.D. in History and Philosophy of Science from the University of Toronto. Her doctoral dissertation examined the recent reclassifications of the Burgess Shale fossils (the remains of ancient and highly unusual marine animals) and their implications for evolutionary biology and paleontology. She is currently working as a Postdoctoral Research Associate for Princeton University, studying the history of ozone depletion science and scientific assessments. Dr. Brysse is particularly fascinated by the responses of paleontologists to the idea that an asteroid impact caused the extinction of the (non-avian) dinosaurs and many other groups 65 million years ago. This subject formed the basis of her master’s thesis, and continues to be a fruitful case study for exploring topics including scientific popularization, discipline formation, and interdisciplinary (non-) communication.

For further information, contact Rick Szostak, Director, STS Program, at rick.szostak@ualberta.ca