Because the most important things are not forgotten
Make do with what you have. The Mesopotamians gave us a very valuable building material the brick. Having no locally available stone they used the plentiful supplies of mud and clay found on the banks of the Euphrates to make bricks.
There is also trade, exchange what you have for what you lack. In their case it was agricultural produce. This is how Babylon became a thriving and powerful city.
Finally when you finally become more powerful take the resources from your neighbours by force.
Answer:
Ocean
Explanation:
It is larger and more vast which has allowed for much more diverse life than in any other ecosystem.