Answer: It shows the evolution of mutations. Throughout the lifetime of animals and humans depending on their way of life and how they life it they will slowly mutate into a different animal to be able to life that way..
Explanation: Example- Whales use to have legs and walked around the earth. But also loved to swim and play in water. Over time they began to adapt and mutate into what we know f whales now. With no legs, they have large fins to help them swim in the oceans.
Basically your answer is Evolution of the Animal
About the geologic time scale divisions
The geologic history of the Earth is broken up into hierarchical chunks of time. From largest to smallest, this hierarchy includes eons, eras, periods, epochs, and ages.
Cells do need food. In a process known as cellular respiration, cells convert biochemical energy (oxygen as food) from nutrients into adenosine triphosphate (ATP), and then release waste products.
hope this helps.. :D