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\nThe main and imminent danger from overpopulation and its effects is the destruction of the ecosystem. This means a disruption of climate, sea rises, pollution, species extinction.\n<\/p>
\nAnother effect is a depletion of resources — primarily food and water. And, as Jared Diamond noticed, the killings in Rwanda were not just due to ethnic hatred, but also due to a scarcity of subsistence land. [See, Jared Diamond, “Malthus in Africa: Rwanda’s Genocide,”<\/a> Collapse<\/i>, 2005]\n<\/p> \nAdding overpopulation and scarcity of resources to war and violence, the result is massive migrations of people into Europe and into the United States.\n<\/p> \nToday, on facebook, I was reminded of experiments done with mice and rats in overpopulated conditions (with adequate food and water) on behavior patterns which lead to extinction. I remember reading in the Scientific American<\/i> in 1962, John Calhoun’s article “Population Density and Social Pathology.”\n\n<\/p>\n The one that today caught my attention is the experiment of John B. Calhoun<\/a>; variously called “mouse utopia,” “behavioral sink,” and “universe 25.” Here is the account of the experiment:\n<\/p> \n