Figure 5 Topography and Drainage

Natural Systems and Human Life

Peru is a complex amalgam of ancient and modern cultures, populations, conflicts, questions, and dilemmas. The land itself offers great challenges. With 1,285,216 square kilometers, Peru is the eighteenth largest nation in area in the world and the fourth largest Latin American nation. It ranked fifth in population in the region, with 22,767,543 inhabitants in July 1992. Centered in the heart of the 8,900-kilometer-long Andean range, Peru's geography and climates, although similar to those of its Andean neighbors, form their own peculiar conditions, making the region one of the world's most heterogeneous and dynamic. Peru's principal natural features are its desert coast the forty great snow-covered peaks over 6,000 meters in altitude, and the mountain ranges they anchor Lake Titicaca, which is shared with Bolivia, and at 3,809 meters above sea level the world's highest navigable lake and the vast web of tropical rivers like the Ucayali, Marañón, and Huallaga, which join to form the Amazon above Peru's "Atlantic" port of Iquitos (see fig. 5).

The Costa, Sierra, and Selva (selva--jungle), each comprising a different and sharply contrasting environment, form the major terrestrial regions of the country. Each area, however, contains special ecological niches and microclimates generated by ocean currents, the wide range of Andean altitudes, solar angles and slopes, and the configurations of the vast Amazonian area. As a consequence of these complexities, thirty-four ecological subregions have been identified.

Although there is great diversity in native fauna, relatively few animals lent themselves to the process of domestication in prehistoric times. Consequently, at the time of European arrival the only large domesticated animals were the llamas and alpacas. Unfortunately, llamas and alpacas are not powerful beasts, serving only as light pack animals and for meat and wool. The absence of great draft animals played a key role in the evolution of human societies in Peru because without animals such as horses, oxen, camels, and donkeys, which powered the wheels of development in the Old World, human energy in Peru and elsewhere in the Americas could not be augmented significantly. As far as is known, the enormous potential in hydrologic resources in preconquest times was tapped only for agricultural irrigation and basic domestic usage. Through the elaborate use of massive irrigation works and terracing, which appeared in both highland and coastal valleys in pre-Chavín periods (1000 B.C.), the environment of the Andes was opened for intensive human settlement, population growth, and the emergence of regional states.

The development of Andean agriculture started about 9,000 years ago, when inhabitants began experimenting with the rich vegetation they utilized as food gatherers. Each ecological niche, or "floor," begins about 500 to 1,000 meters vertically b45 y above the last, forming a minutely graduated and specialized environment for life. The central Andean area is, thus, one of the world's most complex biospheres, which human efforts made into one of the important prehistoric centers of plant domestication. Native domesticated plants number in the hundreds and include many varieties of such important crops as potatoes, maize (corn), lima beans, peppers, yucca or manioc, cotton, squashes and gourds, pineapples, avocado, and coca, which were unknown in the Old World. Dozens of varieties of fruits and other products, despite their attractive qualities, are little known outside the Andean region.

Conquest of the Aztec alliance in Mexico and the Inca Empire (Tawantinsuyu) in the Andes gave impetus to one of the most important features of the colonial process, the transfer of wealth, products, and disease between the hemispheres. Andean plant resources, of course, contributed significantly to life in Europe, Africa, and Asia. Although attention has usually focused on the hoards of Inca gold and silver shipped to Spain and thus funneled to the rest of Europe, the value of Andean potatoes to the European economy and diet probably far exceeded that of precious metals. By the same token, the Spanish conquerors introduced into the New World wheat, barley, rice, and other grains vegetables like carrots sugarcane tea and coffee and many fruits, such as grapes, oranges, and olives. The addition of Old World cattle, hogs, sheep, goats, chickens, and draft animals--horses, donkeys, and oxen--vastly increased Andean resources and altered work methods, diets, and health. The trade-off in terms of disease was one-sided measles, malaria, yellow fever, cholera, whooping cough, influenza, smallpox, and bubonic plague, carried by rats, arrived with each ship from Europe. The impact of these diseases was more devastating than any other aspect of the conquest, and they remain major scourges for the majority of Peruvians.

Data as of September 1992