Microbes defied deadly asteroid
© MARK GARLICK/SCIENCE PHOTO LIBRARY
Microbes made themselves at home in the Chicxulub crater mere days after the asteroid impact that wiped out three quarters of life on Earth.
The asteroid infamously associated with the demise of the dinosaurs struck Mexico 66 million years ago, creating a dust cloud so thick that plants couldn’t grow for several years. Microbial life, however, made a surprisingly rapid return.
A team led by researchers from Curtin University in Australia used organic carbon ratios from a sediment core taken from the middle of the crater to study how microbial communities evolved after the impact. They identified biomarkers of cyanobacteria, which were washed into the crater by a tsunami triggered by the impact. The bacteria survived there even before sunlight levels returned to normal, thanks to nutrients from the surrounding earth.
These findings reveal how nutrient and oxygen supplies can shape the recovery of microbial life in such challenging environments.
- Geology 48, 328−332 (2020). doi: 10.1130/G46799.1