IELTS雅阅读真题.docVIP

　　蚂蚁智力　　Collective intelligence:：Ants and brains neurons　　STANFORD - An individual ant is not very bright, but ants in a colony, operating as a collective, do remarkable things.　　A single neuron in the human brain can respond only to what the neurons connected to it are doing, but all of them together can be Immanuel Kant.　　That resemblance is why Deborah M. Gordon, StanfordUniversity assistant professor of biological sciences, studies ants.　　Im interested in the kind of system where simple units together do behave in complicated ways, she said.　　No one gives orders in an ant colony, yet each ant decides what to do next.　　For instance, an ant may have several job descriptions. When the colony discovers a new source of food, an ant doing housekeeping duty may suddenly become a forager. Or if the colonys territory size expands or contracts, patroller ants change the shape of their reconnaissance pattern to conform to the new realities. Since no one is in charge of an ant colony - including the misnamed queen, which is simply a breeder - how does each ant decide what to do?　　This kind of undirected behavior is not unique to ants, Gordon said. How do birds flying in a flock know when to make a collective right turn? All anchovies and other schooling fish seem to turn in unison, yet no one fish is the leader.　　Gordon studies harvester ants in Arizona and, both in the field and in her lab, the so-called Argentine ants that are ubiquitous to coastal California.　　Argentine ants came to Louisiana in a sugar shipment in 1908. They were driven out of the Gulf states by the fire ant and invaded California, where they have displaced most of the native ant species. One of the things Gordon is studying is how they did so. No one has ever seen an ant war involving the Argentine species and the native species, so its not clear whether they are quietly aggressive or just find ways of taking over food resources and territory.　　The Argentine ants in her lab also are being st