David Dobbs writes: A few years ago, Gene Robinson, of Urbana, Illinois, asked some associates in southern Mexico to help him kidnap some 1,000 newborns. For their victims they chose bees. Half were European honeybees, Apis mellifera ligustica, the sweet-tempered kind most beekeepers raise. The other half were ligustica’s genetically close cousins, Apis mellifera scutellata, the African strain better known as killer bees. Though the two subspecies are nearly indistinguishable, the latter defend territory far more aggressively. Kick a European honeybee hive and perhaps a hundred bees will attack you. Kick a killer bee hive and you may suffer a thousand stings or more. Two thousand will kill you.
Working carefully, Robinson’s conspirators — researchers at Mexico’s National Center for Research in Animal Physiology, in the high resort town of Ixtapan de la Sal — jiggled loose the lids from two African hives and two European hives, pulled free a few honeycomb racks, plucked off about 250 of the youngest bees from each hive, and painted marks on the bees’ tiny backs. Then they switched each set of newborns into the hive of the other subspecies.
Robinson, back in his office at the University of Illinois at Urbana-Champaign’s Department of Entomology, did not fret about the bees’ safety. He knew that if you move bees to a new colony in their first day, the colony accepts them as its own. Nevertheless, Robinson did expect the bees would be changed by their adoptive homes: He expected the killer bees to take on the European bees’ moderate ways and the European bees to assume the killer bees’ more violent temperament. Robinson had discovered this in prior experiments. But he hadn’t yet figured out how it happened.
He suspected the answer lay in the bees’ genes. He didn’t expect the bees’ actual DNA to change: Random mutations aside, genes generally don’t change during an organism’s lifetime. Rather, he suspected the bees’ genes would behave differently in their new homes — wildly differently.
This notion was both reasonable and radical. Scientists have known for decades that genes can vary their level of activity, as if controlled by dimmer switches. Most cells in your body contain every one of your 22,000 or so genes. But in any given cell at any given time, only a tiny percentage of those genes is active, sending out chemical messages that affect the activity of the cell. This variable gene activity, called gene expression, is how your body does most of its work. [Continue reading…]
