How did life evolve in Earth’s early years? No one knows for sure but religion and the scientific community have come up with their own conclusions. Here are some facts that have so far been proven by science.
 
#1 - Evolution
As Earth changed, several early life forms, particularly those who weren’t keen on oxygen died off. While others simply adapted and evolved to the changes of our environment. Just look at the horseshoe crab which has survived four extinction phases.

#2 - Plant Life
Life didn’t just magically appear. It evolved along with the planet as it became more habitable. In fact, we wouldn’t even have continents if it weren’t for early plant life that contributed to the readjustments of tectonic plates, forcing material up to surface.

#3 - The Happening
What happened in the film happened 150 million years after the Cambrian period. Plants began breaking down mineral rocks, which eventually seeped into the ocean, creating algae which suffocated sea life and caused a chain reaction that killed marine and plant life.

#4 - Before The Cambrian Explosion
The animals (including humans) came after what is known as the Cambrian Explosion 542 million years ago. But they didn’t just magically appear. Scientists found fossils that suggest that a species with no skeletal structure existed and may have mutated into the forms of life we are today.

#5 - Common Traits
There are several species that share similar physical traits despite being unrelated such as Koalas, which have fingerprints like humans. Reptiles, like lizards, have characteristics similar to ancient dinosaurs and a brontosaurus and a giraffe have long necks to help them reach plants and fruits.

#6 - Fossil Formation
If you’re looking for fossils, the best place to find them is near a body of water or where there was one. Over time sediment covers and preserves the creatures that will become fossils. In other environments, the creature would just decompose.

#7 - Fossilized
Recreating a model of ancient life from fossils isn’t always perfect or precise. That’s because most creatures were only partially fossilized. So scientists get the whole picture by using the physiology of these creatures’ modern descendants.

#8 - Martian Life
The only planet in our system likely capable of having once supported life is Mars. It once had rivers and oceans. We learn a lot about ancient life through fossils. Imagine what the first colonists will discover about Martian life if and when they find fossils there too.

#9 - Survivors
Despite the massive extinction of several ancient species some have actually survived and evolved such as Cyanobacteria, which created oxygen on Earth. Insects such as the Rove Beetles existed 200 million years ago and continue to exist.

Interesting

Another crazy fact is that the planet would be pink if oxygen loving flora didn't exist, as the first plants were anaerobic pink proto-plants...