What was the most important cause of these dual revolutions and what was the ultimate result of these inequalities?

In his book, Changes in the Land: Indians, Colonists, and the Ecology of New England, historian William Cronon writes that “the replacement of Indians by predominantly European populations in New England was as much an ecological as a cultural revolution” (p. 6). In your opinion, what was the most important cause of these dual revolutions and what was the ultimate result of these inequalities?