Ecological Imperialism

"If we seek the roots of the success of European imperialism, we must be off to the Middle East, to Abraham, to Gilgamesh and the cultural ancestors of all of us who eat wheaten bread, smelt iron, or record our thoughts alphabetically… We – you who read and I who write this sentence – are part of that continuity; these words are in an alphabetical form of writing, a very clever Middle Eastern invention produced by peoples even more directly influenced by the Sumerian example than we are. The Sumerians and the inventors of the alphabet, and you and I, no matter what our genetic heritage, are in one category: heirs of post-Neolithic Old World cultures. All Stone Age peoples, including the few living, and all pre-Columbian Amerindians, however sophisticated, are in another. The indigenous populations of the Neo-Europes were in the second category until Europeans arrived from beyond the seams of Pangaea. The transition from one category to another was a harrowing one, and many individuals and even peoples faltered and failed."

"Between 1920 and 1930, well over 50 million Europeans migrated to the Neo-European lands overseas. That number amounts to approximately one-fifth of the entire population of Europe at the beginning of that period. Why such an enormous movement of peoples across such vast distances? Conditions in Europe provided a considerable push--population explosion and a resulting shortage of cultivable land, national rivalries, persecution of minorities--and the application of steam power to ocean and land travel certainly facilitated long distance migration. But what was the nature of the Neo-European pull? The attractions were many, of course, and they varied from place to place in these new-found lands. But underlying them all, and coloring and shaping them in ways such that a reasonable man might be persuaded to invest capital and even the lives of his family in Neo-European adventures, were factors perhaps best described as biogeographical."

"The members of the portmanteau biota had at least the same advantage as had the first humans and their associated organisms that crossed into the New World from Eurasia: the advantage of moving into virgin territory and, with luck, leaving a lot of enemies behind. Back in the Old World, most particularly in the densely populated areas of civilization, many organisms had taken advantage of contiguity with humans and their plants and animals to become their parasites and pathogens. These freeloaders often were slower to emigrate to the Neo-Europes than were humans and the organisms that humans intentionally brought with them. For example, Europeans brought wheat to North America and created the first of their several wheat belts in the Delaware River valley in the eighteenth century where the plant thrived in the absence of its enemies. Then its old nemesis, the Hessian fly, unjustly blamed on George III's mercenaries, who supposedly brought it across the Atlantic in their straw bedding, arrived and obliged farmers of the valley to find a new staple."

Ecological Imperialism: The Biological Expansion of Europe 900-1900 by Alfred W. Crosby (1986)