National Geographic : 2007 May
T IS JUST POSSIBLE that John Rolfe was responsible for the worms-specifically the common night crawler and the red marsh worm, creatures that did not exist in the Americas before Columbus. Rolfe was a colonist in Jamestown, Virginia, the first successful English colony in North America. Most people know him today, if they know him at all, as the man who married Pocahontas. A few history buffs understand that Rolfe was one of the primary forces behind Jamestown's eventual success. The worms hint at a third, still more important role: Rolfe inadvertently helped unleash a convulsive and permanent change in the American landscape. Like many young English blades, Rolfe smoked-or, as the phrase went in those days, "drank"-tobacco, a fad since the Spanish had first carried back samples of Nicotiana tabacum from the Caribbean. Indians in Virginia also drank tobacco, but it was a different species, Nico tiana rustica.Virginia leaf was awful stuff, wrote colonist William Strachey: "poor and weak and of a biting taste." After arriving in Jamestown in 1610, Rolfe talked a shipmaster into bringing him N. tabacum seeds from Trinidad and Venezuela. Six years later Rolfe returned to England with his wife, Pocahontas, and the first major shipment of his tobacco. "Pleasant, sweet, and strong," as Rolfe's friend Ralph Hamor described it, James town's tobacco was a hit. By 1620 the colony exported up to 50,000 pounds of it-and at least six times more a decade later. Ships bellied up to Jamestown and loaded up with barrels of tobac co leaves. To balance the weight, sailors dumped out ballast, mostly stones and soil. That dirt almost certainly contained English earthworms. And little worms can trigger big changes. The hardwood forests of New England and the upper Midwest, for instance, have no native earth worms-they were apparently wiped out in the last Ice Age. In such worm-free woodlands, leaf litter piles up in drifts on the forest floor. But when earthworms are introduced, they can do away with the litter in a few months. The problem is that northern trees and shrubs beneath the forest canopy depend on that litter for food. Without it, water leaches away nutrients formerly stored in the litter. The forest becomes more open and dry,los ing much of its understory, including tree seedlings. Whether the night crawler and the red marsh A coastalIndian depicted in 1585 by voyager and artistJohn White resembles the Powhatan hunters the English encountered atJamestown in 1607. Though the region appearedsparsely inhabited to the settlers, more than 15,000 Indians were using nearly every squarefoot to farm, hunt,fish, andgather. Charles C. Mann is the best-selling author of 1491: New Revelations of the Americas Before Columbus.