National Geographic : 2006 May
VOICES EDWARD 0. WILSON these colonies can prevail over solitary individuals. That was the solution. And actually that isn't too far from the way we see it today. The most recent theories will be spelled out in detail in a book that Bert Holldobler and I are now finishing and hope to have in print soon called The Superorganism. Why that title? The colony is the next level of biological organization. The colony, by group selection, has developed traits that could not be possible otherwise-communication, the caste system, cooperative behavior. It's a unit of activity and of evolution. One colony against another is what's being selected. This hap pens to be close to Darwin's idea but in modern genetic terms. How does this kind of social behavior get started? It has to do with defense against enemies. Naturalists have discovered more and more groups that have altruistic workers and soldiers-ants, termites, certain beetles, shrimp, and even a mammal, the naked mole rat. What's consistently the case is that these animals have a resource, usually a place to live with food, that's very valuable. If you're a solitary indi vidual and you build a chamber like that, somebody could chuck you out. The idea is that these lines are going to find it advantageous to develop sterile castes for maintaining and protecting the colony. So this is a story about community and home. I've learned my lesson about jumping from ants or sponges to humans! But it does, in my opinion, call for another look at human origins. Anthropologists now pretty much agree that a major factor in human origins was having a habitation, a campsite, which allowed for some specialization, where some stayed and looked after the site and the young and so on, while others ventured out to bring food back. And the pressures from predators must have been pretty intense. But we don't have sterile castes. No, we have a division of labor. That is very true. And that's a fundamental difference between us and insects and these other creatures, and that's why we have to be very careful about drawing analogies. Because human beings are so flexible and intelligent, we can divide labor without physical castes. That system has worked pretty well for ants. They dominate ecosystems. In tropical forests, from one study, ants alone make up four times the weight of all the land vertebrates put together-amphibians, reptiles, birds, mammals. The weight of all the ants in the world is roughly the weight of all the humans, to the nearest order of magnitude. They are the principal predators of small animals, the principal scavengers in much of the world, and the principal turners of the soil.