Gill to explore why ferns flourished after asteroid strike that doomed dinosaurs
Ferns have staying power.
The vascular plants have existed for about 350 million years, even surviving nuclear winterlike conditions — global dimming, cooling and acid rain — 66 million years ago that wiped out dinosaurs and 75% of other animals and plants on Earth.
Jacquelyn Gill, a University of Maine paleoecologist, will explore fern resilience with an all-female research team that includes scientists from the University of Florida (lead institution), University of Wyoming, University of California Santa Cruz, and the Natural History Museum of Los Angeles County.
NASA’s Exobiology program is awarding $1,193,212 for the three-year project, of which Gill will receive $343,380. The scientists will conduct interdisciplinary research in the context of NASA’s “ongoing exploration of our stellar neighborhood.”
The team’s findings could prove significant on a grand scale.
Gill and colleagues may uncover information that will be valuable for living in changing and challenging climate conditions on Earth, as well as for recovering from a mass extinction, and living on planets that are currently uninhabitable.
They’ll begin by examining how ferns recolonized soon after a large asteroid or comet struck Mexico’s Yucatan Peninsula around 66 million years ago.
The fossil record contains a visible impact boundary layer, which separates information about what the natural world was like before and after the asteroid/comet strike.
The devastation and abrupt climate change after the strike reshuffled the structure of Earth’s vegetation for thousands of years.
While the strike is associated with dinosaurs going extinct, Gill says its impact on plants — which form the foundation of ecosystems across the planet — also was far-reaching.
In fact, for thousands of years after the impact, Gill describes the area as “fern world,” as forests were leveled and most flowering plants were wiped out.
Ferns produce male and female sex organs and self-fertilize. And their dust-like spores disperse long distances and can enter the jetstream.
Surprisingly, until now, attributes that made ferns so resilient in the harsh post-impact environment haven’t been explicitly investigated.
“Are they the first to colonize a new landscape, or is there something special about their biology that helps them survive harsh environments?” asks Gill.
This summer, the team will go in the field and visit museums. Along with paleontologists at the University of Wyoming and the Natural History Museum of Los Angeles County, Gill will analyze ancient spores and leaves, and their chemistry and shapes. Her research will establish the parameters for the growth experiments that the team’s fern biologists will conduct.
Scientists who specialize in modern flora will grow both ferns and seed plants in chambers that mimic conditions similar to those that existed after the impact — darkness, acid rain, dust, high CO2, and heavy metals in soils.
They’ll then evaluate the plants’ functional traits, including efficiency of carbon and light capture in mature leaves.
Emily Sessa, associate professor of biology at the University of Florida, submitted the abstract titled, “Surviving a Mass Extinction: Lessons from the K-Pg Fern Spike” to NASA.