Manage episode 235767120 series 1229115
What is the most abundant life in the Universe? That’s a bold question, considering we have yet to see undisputed proof that ET even exists. The only model we have, is on Earth. So let’s unpack that, and see what we end up with.
Earth, 4.6 billion years old. That’s our scale. The scale has already been split into four eons.
The first eon is called Hadean. That first eon, lasted from 4.57 billion to 4.1 billion years ago. At 4.53 billion years, a mars sized object hit the earth, forming the moon. At 4.1 to 3.8, water and organic material begin falling to Earth.
It would be during this eon 4.0-2.8 billion years ago, where life on Earth took a foothold, the Archean eon. They were single celled creatures including microscopic microfossils.
At 3.6 billion years, we can see the emergence of cyanobacteria. These little guys begin to produce oxygen in Earths’ great oxygenation event.
2.5 billion years ago, Earths oxygen level begins to significantly rise.
Notice that Earth is almost half as old as it is now, yet populated with these simple life forms, and there’s nowhere near enough oxygen in the air for animals or humans.
Once the oxygen level starts to rise, multi-celled organisms start showing up. The cells have a protected nucleus, which now house DNA.
At 2 billion years ago, photosynthesis begins to produce more oxygen. Creatures start using oxygen to process fat, sugar, and protein.
At a billion years ago, a super continent forms. Life looks like cool sponges and funky worms. Half a billion years ago, the Cambrian explosion gives rise to more complex animals that evolve and diversify rapidly.
490-445 million years ago, we see the first plants and fungi appear on land, then an Ice age. After this time, jawed fish appear, then more complex plants, increasing oxygen, winged insects.
Then 252 million years ago, the Great Dying event wipes out 95% of life on Earth. Then Dinosaurs take over the planet until Bam, a big rock from the sky wipes them out.
With nothing around to eat plants, plants become trees. Forests become the new modern habitat. With all that food around, mammals start getting bigger and bigger. The first primates appear. Those opposable thumb tree swingers eventually hit the ground That’s when the Earth became the Planet of the Apes