The Same Asteroid That Killed the Dinosaurs Likely Made Earth's Rainforests

The adage goes something along the lines of "You win some, you lose some," right? When it comes to the third rock from the Sun, that means the same asteroid that wiped out the planet's dinosaur population likely served as the catalyst behind the growth of the world's rainforests.

A new study published by the Smithsonian Tropical Research Institute (STRI) and the Chicago Botanic Garden's Negaunee Institute for Conversation Science and Action suggests the Earth's plant coverage was relatively sparse until the Chicxulub impact, the name for the event of the asteroid that eventually caused the extinction of dinosaurs.

“Forests disappeared because of the ecological catastrophe... and then, the returning vegetation was mostly dominated by flowering plants,” STRI's Mónica Carvalho wrote in the study.

“Our study follows a simple question: How do tropical rainforests evolve?” Carvalho added. “The lesson learned here is that under rapid disturbances—geologically speaking—tropical ecosystems do not just bounce back; they are replaced, and the process takes a really long time.”

The study first started 20 years ago with the group studying over 56,000 fossils — 6,000 leaf and 50,000 pollen — from Colombia and surrounding areas. According to the scientists involved, nearly half of the species ceased to exist after the asteroid crash-landed on the planet, allowing ferns and other flowering plants to take over the forests.

In the study, scientists reveal three hypotheses for the rise of the rain forest, the first being a world without dinosaurs meant fewer animals would trample through the ecosystem while eating flowers, leaves, and other forestation. Naturally, this would allow the plants to grow unchecked.


The second idea suggests the impact of the asteroid itself is responsible for thrusting the tropic's coniferous population into extinction, while the third posits the asteroid's collision set off a chain of events that fertilized the rainforest soil and allowed new foilage to grow. After impact, tsunamis would have carried various debris and sediment that would settle over time. That combined with the ash in the atmosphere could have produced the perfect environment for the plants to take over.

“The changes we are seeing today in relation to climate and deforestation are so rapid that we haven't really seen them in any other scenario in the history of the planet,” Carvalho warned. “Extinction is something that occurs really fast.”