<P> As noted, the change of requiring the encomendado to be returned to the crown after two generations was frequently overlooked, as the colonists did not want to give up the labor or power . The Codice Osuna, one of many colonial - era Aztec codices (indigenous manuscripts) with native pictorials and alphabetic text in Nahuatl, there is evidence that the indigenous were well aware of the distinction between indigenous communities held by individual encomenderos and those held by the crown . In 1574, the Viceroy of Peru Diego Lopez de Velasco investigated the encomiendas . He concluded there were 32,000 Spanish families in the New World, 4,000 of whom had encomiendas . They oversaw 1,500,000 natives paying tribute, and 5 million "civilized" natives . </P> <P> The phrase "sin indios no hay Indias" (without Indians, there are no Indies--i.e. America), popular in Spanish America especially in the 16th century, emphasizes the economic importance and appeal of this indentured labor . It was ranked higher than allocations of precious metals or other natural resources . Land awardees customarily complained about how "worthless" territory was without a population of encomendados . </P> <P> The native people of Mexico experienced a series of outbreaks of disease in the wake of European conquest, including a catastrophic epidemic that began in 1545 which killed an estimated 5 million to 15 million people, or up to 80% of the native population of Mexico, followed by a second epidemic from 1576 to 1578 killing an additional 2 to 2.5 million people, or about 50% of the remaining native population . Recent research suggests that these infections appear to have been aggravated by the extreme climatic conditions of the time and by the poor living conditions and harsh treatment of the native people under the encomienda system of New Spain . </P> <P> Raphael Lemkin (coiner of the term genocide) considers Spain's abuses of the Native population of the Americas to constitute cultural and even outright genocide including the abuses of the Encomienda system . He described slavery as "cultural genocide par excellence" noting "it is the most effective and thorough method of destroying culture, of desocializing human beings ." He considers colonist guilty due to failing to halt the abuses of the system despite royal orders . He also notes the sexual abuse of Spanish colonizers of Native women as acts of "biological genocide ." Yale University's genocide studies program supports this view, citing the decline of the Taíno population of Hispaniola in 1492 to 1514 as an example noting their population declined from 1,000,000 to 100,000 to only 32,000 a decline of 68% to over 96% . Those numbers are largely based on the accounts of Las Casas and the letters that wrote during the epidemics . Darcy Ribeiro considers that native exploitation was the fuel of the productivity of the Spanish Colonies and, H.F. Dobyns estimated 95% . </P>

Legal rights to native labor as granted by the spanish crown