Jonathan Wilson, Haverford College – Re-Animating Extinct Plants

Planetary history can hold keys to preserving species when the climate changes.

Jonathan Wilson, assistant professor of biology and environmental studies at Haverford College, examines how plant fossils can help current plants survive for generations.

I received my B.A. in Computer Science and Earth and Planetary Sciences from Johns Hopkins University in 2003 and a Ph.D. in Earth and Planetary Sciences from Harvard University in 2009.  After two years as an O K Earl Postdoctoral Scholar in Geology and Postdoctoral Scholar in Geobiology at Caltech, I joined the Biology Department at Haverford in 2011 as an environmental biologist.  I enjoy field-based work, whether geological or botanical in nature, and try to spend my summers near some combination of plants, rocks, and trout.

Re-Animating Extinct Plants

There’s a famous quote often misattributed to Yogi Berra: “It is difficult to make predictions, especially about the future.”
How can we arrive at better estimates of the way climate change will impact ecosystems? There’s only one Earth, after all, so a global experiment is impossible—and undesirable.
The answer is by turning to planetary history. There’s a rich archive of environmental conditions preserved in fossils. Plant fossils, in particular, are key sources of environmental information— aspects of plant anatomy, including leaf size, leaf shape, and wood structure, record and respond to environmental change in a predictable, biophysical way. The same aspects of form and function that distinguish an oak forest in Spain from a tropical grove in Brazil can be inverted to derive environmental information from plant leaf and stem fossils.
Our research applies fluid dynamics models to fossilized plant cells extracted from geological material to determine extinct plants’ water transport and photosynthetic rates. Through this process, we can quantify the performance and limits of extinct plants. We’ve found plants that lived hundreds of millions of years ago that could transport water and photosynthesize at magnitudes comparable to living plants—but using entirely different anatomical structures that left them more vulnerable to environmental change, such as droughts. This vulnerability may have amplified climatic changes during the Carboniferous period—extinction and replacement of these forests may have transformed the carbon and water cycles of that era. It’s a cautionary tale for the impacts of drought stress and deforestation in our own era.
One way to make better predictions is to look to the past, and the history of plant life holds important clues about the planet’s future.