Look at the map. Which ecosystems show where early civilizations developed because the area allowed people to grow crops even during times with little rainfall? Select all that apply.

-Desert

-RainForest

-Savanna

-sahel

The Ecosystems that show where early civilization occurred are Savannah and Rain forest Ecosystems because the areas allowed  people to grow crops even during the time of little rainfall.

Explanation:

Savannah Ecosystem actually started as rainfall inadvertently reduced around the tropics during the olden days especially between 66 million to 25 million years ago according to various resources available. The most dominant vegetation in the Savannah nowadays are grasses apart from the covered trees. Even the grasses must have appeared about 50 million years ago although there may be some possibility that some Ecosystems like Savannah may have existed earlier than that. From various online resources, it is evident that the first human to appear on earth may have appeared in the SAVANNAH REGION of Africa after which he ensure various resources in the environments were modified before moving and spreading to other continents.

However, the Rain forest region is the ecosystem that usually occur in high annual rainfall areas all around the earth.The trees are of broad leaves and always evergreen. The ares are mostly with one river or the other e.g Nile River, Amazon River, Congo River. This Ecosystems must have been in existence for over 500 million years according to various researches thus giving credibility to the fact that it is among the two Ecosystems that ensure early civilization all year round just like Savannah Region with low level of rainfall then.

c.) biotic: snails; abiotic: temperature climate

b. ensure mutual protection from communism.

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