Why did some European attempts to establish colonies in the New World fail?

How did Europeans interpret the New World through some of their earliest visual depictions?

What arguments did Bartolome de Las Casas make in favor of more humane treatment of Native Americans as he exposed the atrocities of the Spanish conquistadors in Hispaniola?

In what ways did the arrival of Europeans to America bring about unforeseen and unintended consequences for the people and environments of both the New World and the Old?