Alumni & Friends
She Begs to Disagree
Gerta Keller (B.S.,’73) remembers her first talk at a major scientific conference, when she shared her research on the mass extinction event that killed the dinosaurs. “There was near pandemonium [in the room] with many scientists lining up behind a microphone to denounce me for the data I presented,” she recalls. “It was very surprising that the mere presentation of scientific data could trigger such a violent reaction and personal attacks.”
That’s not the typical audience reaction at a science meeting, but in 1985 Keller was disputing the “beautiful and popular” hypothesis that a massive meteorite impact near the Yucatan Peninsula years ago had wiped out 60 to 75 percent of all plant and animal species. Since then, the Princeton University geoscientist and her colleagues have compiled a painstaking record from rock layers and microscopic fossils around the world that they say undermines the idea that cosmic impact is the extinction’s smoking gun. It’s more likely, they suggest, that a huge outpouring of volcanic gases in India was responsible for the mass die-off 65 million years ago.
The personal attacks haven’t stopped, although Keller has learned to put them in perspective. “I’m dedicated to the search for the real cause of mass extinctions simply because I want to know, because it helps us understand the history of life and maybe understand what lies in store for the future,” she says. “But this kind of idealism is not always welcome in science.”
Upheaval interests Keller, whether it’s dissenting from her colleagues or learning more about the dramatic turnovers of life that have punctuated the earth’s history. She left her home in Switzerland as a teenager, and spent a tumultuous youth traveling around the world where she weathered hepatitis and almost died as an unlucky bystander in an Australian bank robbery. In 1968, she came to San Francisco and began life again as a student.
“This was during the flower children days of Haight-Ashbury, an exciting time to be in the U.S.,” she remembers. She came to SF State to major in anthropology, but she switched to geology soon after taking a class with Professor Hans Thalmann. “He was a kind, laid back professor going with the time — and a great teacher.” He convinced her that geology would keep her on the road, she says, “because there are always rocks you can study any- where you want to go, and someone will pay you to study them.”
Keller’s studies have taken on new urgency, she says, as modern- day ecologists look to her work on past extinctions to help them predict future species devastation. “We are now in a time of very rapid climate warming, ocean acidification and species extinctions that far exceed the tempo of any mass extinctions in the past,” she notes. “That should give us pause.”
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