Neogene
The beginning of humankind 20 mya
Life forms begin to spread out.
The climate had begun to dry and cool, causing most animals to either adapt or die. Because of the decreasing food sources, animals began fighting and depleting food. Naturally animals began spreading out, and adapting to the new climates.
The earth looked nearly the same.
The earth was in the process of settling to it's current state, so it looked very similar to how it does now. Mountains were still developing and some plates were closer to each other than how they are today.
The climate
Sea levels plummeted as the Ice Caps grew and thickened, both Due to the climate get cooler, though it wasn't nearly as cold as today's climate, it definitely was cold for the animals, who were forced to spread out.
Evolution
Evolution is gradual change over a long period of time, making small mutations more and more prevalent until it's rare to not have the mutation. Humankind experienced a lot of evolution during the Neogene. Evolution has much relevance and is widely accepted amongst the scientific community.