Water
Weathering and erosion, along with thegravity-driven effect called mass wasting, are the fundamental processes by which rock is broken down and removed, collectively called denudation. The most important agent in both weathering and erosion is water, in both its liquid and solid states.
Bacterial cells grow and divide rapidly. In order to do this, bacteria take in nutrients through their Cell Membranes.
Your brain sends signals to your body to release hormones that make you tired. This is done as a routine, and trying to sleep at different times will mess it up.
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When the organism become bipedal, they walk with 2 legs so there are 2 arms that were unused. Some of them try to use that hand by grabbing stick or stone, leading to tools. They start to think more to develop tools and their brain capacity become increased.
The ability to use stone tools will help in food digestion since it can break the food easier. This reduces the needs for bigger teeth/jaw.