land into cultivation, with potatoes being the main source of carbohydrates. Llamas and alpacas were domesticated. While llamas could carry burdens of up to 50 kilos, they were not harnessed for agricultural work. Both were sources of dietary protein. In areas not suitable to sedentary agriculture, there were usually small bands of people, often extended kin groups, who pursued hunting and gathering on a gendered basis. There were no domesticated large animals suitable for domestication that could be used as beasts of burden or transportation. When the Spaniards introduced horses in desert and semiarid regions, they were acquired by many indigenous groups, transforming their ways of life. Environmental transformations, ca. 1500-1825 Indigenous peoples had shaped the environment and utilized its resources, but Europeans even more significantly changed the environment with large-scale resource extraction, especially mining, as well as the transformation of agriculture to cultivation of crops to feed urban populations and the introduction of livestock, used for food, leather, wool, and tallow. Deforestation increased at a rapid pace and water resources were appropriated by Europeans. Disease and demographic collapse With the deliberate importation of Old World plants and animals and the unintentional spread of diseases brought by the Europeans (smallpox, measles, and others) changed the natural environment in many parts of Latin America. European diseases devastated indigenous populations. The demographic catastrophe of natives on islands first settled by the Europeans prompted their exploration of others in the Caribbean and slave raiding, with consequences for the overall demography of the Caribbean. Then as Europeans explored and settled further, the demographic catastrophe was further replicated in the sixteenth century. Recently, scientists have been considering whether the population loss had an impact on carbon dioxide levels, which might well have led to the "Little Ice Age." Commodities and the environment in the early colonial era Placer mining of gold in the Caribbean did not have a major impact on the natural environment, but it did have a devastating impact on the indigenous populations. Europeans sought indigenous labor for placer mining to the exclusion of other activities, including tending crops. The Europeans initiated slave raiding elsewhere in the Caribbean. Venezuela and the islands of Cubagua and Margarita Island was found to have rich deposits of pearl oysters. Natives of the region had long harvested them, and traded them with Europeans. The Europeans’ demand for pearls increased and the careful and selective indigenous methods gave