Answer:
there is no sun
Explanation:
plants and organisms need the sun to produce there food.
There was no unified state that could grow all parts of life equally so they had to depend on trade in order to get goods that they needed from each other since they couldn't develop all parts of production or manufacture. Ones would for example have a developed pottery industry while the others would have mastered making Olive oil so they would trade in order to get what they needed because they couldn't make it on their own.
