The Huck Institutes of the Life Sciences
PennState University
Presentation Title
Mass extinctions and our role in causing them
Abstract
During the last 60,000 years, more than 70% of the large-bodied animals, or megafauna, that lived in North America went extinct Despite decades of research, the reasons for this tremendous loss of biodiversity remain unresolved. Two sources of environmental change in particular are often held responsible: global climate change, specifically that associated with the peak of the last ice age around 21,000 years ago, and the first appearance of large numbers of humans in North America around 14,000 years ago. To address this question, we extract and sequence genetic information from the bones, teeth and other remains of species that went extinct, including mammoths, horses, lions and woolly rhinoceros, as well as species that survived, such as bears, bison, muskox and caribou. These genetic sequences contain within them a precise record of what happened to these populations, making it possible to find out when populations were growing or shrinking, when animals were moving across vast areas of geographic space in search of suitable habitat, and how quickly the extinction happened once the decline began. By comparing the evolutionary history of these different species, we hope to better understand both the process of extinction and our role as humans in shaping the ecosystem in which we live.
Biographical
Beth Shapiro is an evolutionary biologist who specializes in the genetics of ice age animals and plants. A pioneer in the young field called “ancient DNA,” Beth travels extensively in the Arctic regions of Alaska, Siberia and Canada collecting bones and other remains of long-dead creatures including mammoths, giant bears, and extinct camels and horses. Using DNA sequences extracted from these remains, she hopes to better understand how the distribution and abundance of species changed in response to major climate changes in the past, and why some species go extinct while others persist. The results could be used to help develop strategies for the conservation of species that are under threat from climate change today.
Professor of Biology at Penn State University and a research associate of the Denver Museum of Natural History, Shapiro has been widely honored for her research. She was recently named a Searle Scholar, Packard Fellow, and a National Geographic Emerging Explorer. In 2009, she received a MacArthur “genius” award.
Further Information
Shapiro Laboratory Website
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