Sunday, August 21, 2011
The alignment of Eurasia had a huge impact on the expansion of the human race. As it is expected, Eurasia's east-west axis made the spread of crops easier. Moving east-west versus north-south has the advantage of having virtually the same lines of latitude, which have similar day lengths and climates. Plants that were domesticated to grow in climates like that of the Fertile Crescent will have a greater chance of prospering in the areas to the east and west of origin. Moving from north-south would have dramatically different results. Plants made to grow in the warmer climate of Mexico would not grow as well as in the cold climates of Alaska. "The plant would also lack genes for resistance to diseases of northern climates, while uselessly carrying genes for resistance to diseases of southern climates," (184). North-south axis varies in climate so much that plants grown in southern latitudes have no chance of germinating in northern latitudes. Humans migrating from Mexico to Alaska would have a difficult time keeping their crops alive. Plants would undoubtedly die of frosts before they had fully matured and were able to produce food. Without enough food to sustain themselves, they would surely begin to die out. And without crops and grains, domesticating animals would be out of the question. Lack of animals means lack of wool, milk, leather and, of course, meat. However, east-west axis provides a similar enough climate and latitude to enable "germination, growth, and disease resistance of plants" to adapt to more easily (184). The east-west alignment was the most important factor in determining civilizations because without the ability to produce enough food to support a large group of people while migrating, humans would not survive, hence civilizations would not exist. Eurasia was an ideal place for a beginning civilization. Because of the Fertile Crescent and all the prosperity that it brought, plants, animals and humans were able to spread out. There is enough land to the east and west with similar enough climate and day lengths that humans were able to adjust with ease. Crops grew just as well in other areas similar to the Fertile Crescent. This is the base enabling humans to maintain large amounts of livestock. And with food comes the a writing system. If people spent all their time hunting and gathering, no one would have time to create a writing system. Overall expansion is the most important. It gives humans more land to prosper in.