The origin of the Amazon remains an enigma. An asteroid and an inland sea could hold the key.
On September 5th, the , a date that commemorates the magnitude of the world’s largest tropical rainforest. But beyond its present state, the big question remains: how was this biome born? The latest research combines to propose a much more unexpected origin than we imagine.
### An asteroid that changed everything
, the same asteroid that ended the dinosaurs 66 million years ago could also be the starting point of the current . The analysis of 50,000 grains of fossilized pollen and 6,000 leaves shows that the impact altered the dominant flora: the gymnosperms, unable to adapt, gave way to angiosperms, plants with flowers and fruits that thrived in the new environment.
That cataclysm opened a cycle of accelerated speciation, in which new species found niches to grow and diversify. From that transformation
### When the Caribbean Sea bathed the jungle
adds a second chapter. During the Miocene, less than 10 million years ago, the Caribbean Sea penetrated more than 2,000 kilometers inland, creating an immense mosaic of wetlands, saline swamps, and estuaries. This scenario forced organisms to adapt to extreme conditions and fostered
Fossils of plankton, mollusks, and marine fish found in the region support this hypothesis. Even , like the river dolphins of the Amazon, could be heirs of that time when the jungle was also a sea.
### The laboratory of life
Today, according to Christopher Dick, a biologist at the University of Michigan, the comparison is eloquent: in Eastern North America there are about 300 tree species; in a single hectare of the the same 300 can be counted.
Scientists agree that there is still much to discover. is not a single narrative, but a mix of global catastrophes, marine invasions, and millions of years of evolution that made possible the planet’s most vast crucible of life.
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