10 January, 2013

Overpopulation's social cost, in mice:

CABINET // The Behavioral Sink: On day 560, a little more than eighteen months into the experiment, the population peaked at 2,200 mice and its growth ceased. A few mice survived past weaning until day six hundred, after which there were few pregnancies and no surviving young. As the population had ceased to regenerate itself, its path to extinction was clear. There would be no recovery, not even after numbers had dwindled back to those of the heady early days of the Universe. The mice had lost the capacity to rebuild their numbers—many of the mice that could still conceive, such as the “beautiful ones” and their secluded singleton female counterparts, had lost the social ability to do so. In a way, the creatures had ceased to be mice long before their death—a “first death,” as Calhoun put it, ruining their spirit and their society as thoroughly as the later “second death” of the physical body.