The central nervous system by sending messages from the brain through the nerves that go to your spine.
<span>The mountains were once seas. The land was forced up by tectonic motion when the mountains were formed. The Sahara also used to be a sea and has a valley full of the fossilized remains of an extinct species of whale. It is generally agreed upon that two plates colliding caused the uplift that created the mountainous zone. Same for the Himalayas.</span>
Answer:
Hey there!
A population increase follows a period of scarcity.
With more people, the food and water resources get scarce, and isn't always enough for everyone.
Let me know if this helps :)
I don't know exactly what you mean but the size of a group affects its defense because there is a larger group. Therefore, more people would be protecting it, adding more to its defense.
