Select which actions had unintended consequences from the Colombian Exchange
Europeans bring wheat to the Americas. Wheat becomes a successful crop.
Some sailors had smallpox and come in contact with Natives who contract the disease and die after infecting their relatives.
Spanish conquistadors bring horses with them. Some horses escape or swim to shore after a ship sinks. Plains Indians become expert horsemen and buffalo hunters
Europeans take potatoes with them and they become an important source of nutrition in Europe
