About 66 million years ago, the Chicxulub impactor asteroid struck the Earth at Chicxulub Pueblo on the Yucatan Peninsula in Mexico igniting wildfires and a cloud of dust and ashes darkened the skies for years. There is a lot of evidence which shows that the asteroid had been the major reason for the Cretaceous- Palaeogene extinction event which was a sudden extinction of three-quarter of plants and animals of that region.
The researchers from Smithsonian Tropical Research Institute (STRI) led a study that had both theory and practical evidence that showed the rainforest in the region of craters were different before the hit by the asteroid. They have examined thousands of fossil pollen and leaf fossils over many sites in Columbia which show a clear picture of different species of plants and animals that existed millions of years ago. They state that the phase when the dinosaurs became extinct and when the asteroids hit the Earth were around the same time, so they concluded that the asteroids become the major cause for the extinction of many species of plants and animals including dinosaurs.
Leaf fossils and pollen found in that region show that the rainforest before this incident were different. Rainforests were formed by monkey puzzle trees, flowering plants and abundant ferns. Trees grew widely spaced from each other allowing sunlight to reach the forest ground. There were dinosaurs and different species of insects that lived on selected leaves.
The asteroid impact changed it all. Nearly half of plant species in the tropic went extinct and a new type of rainforest began to grow. It had fewer numbers of species, most of which were flowering plants, monkey puzzle trees disappeared and only a few ferns remained. Trees grew competing for light. They formed dense forests in which plants with different growth habits evolved. The forest floor was now darker. Larger dinosaurs were gone and insects fed indiscriminately on all available leaves. Now there are majorly flowering plants in the rainforests and the dense trees and plants have become less. Dinosaurs played a key role in balancing the dense plants but the asteroids changed the entire environment balance.
The impact also caused Tsunamis, wildfires and a massive amount of debris and aerosols that enshrouded the planet, darkening the skies and cooling the atmosphere.
The Amazon rainforest that is believed to be formed from the asteroid’s hit millions of years ago is now again in danger because of different human activities and one of them being deforestation and according to the facts almost 15% of the forest has been destroyed for human activities. Other activities include making roads, highways, oil drilling activities and opening new trade centres.
Asteroids are the biggest risk in the short-term and therefore we should monitor the sky and make sure that there is no big enough object approaching Earth in our life. Millions of years ago when it approached the earth and destroyed many plants and animals, it gradually gave birth to another forest full of plants and shelter for animals and birds. But the activities done by humans in this generation will destroy the land completely and will take millions of years ahead to bring it to its original form.
The research definitely gives us a lead on how the asteroids impacted the environment on earth. The extinction of dinosaurs and other species and rise of Amazon rainforest is linked and there is evidence that proves the research.