the fertile crescent is different from much of the middle east because it
Fertile Crescent As crucial as rivers and marshlands were to the rise of civilization in the Fertile Crescent, they were not the only factor. The area is geographically important as the "bridge" between Africa and Eurasia, which has allowed it to retain a greater amount of biodiversity than either Europe or North Africa, where climate changes during the Ice Age led to repeated extinction events when ecosystems became squeezed against the waters of the Mediterranean Sea. The Saharan pump theory posits that this Middle Eastern land-bridge was extremely important to the modern distribution of Old World flora and fauna, including the spread of humanity.