When the Europeans arrived, carrying germs which thrived in dense, semi-urban populations, the indigenous people of the Americas were effectively doomed. They had never experienced smallpox, measles or flu before, and the viruses tore through the continent, killing an estimated 90% of Native Americans.
Smallpox is believed to have arrived in the Americas in 1520 on a Spanish ship sailing from Cuba, carried by an infected African slave. As soon as the party landed in Mexico, the infection began its deadly voyage through the continent. Even before the arrival of Pizarro, smallpox had already devastated the Inca Empire, killing the Emperor Huayna Capac and unleashing a bitter civil war that distracted and weakened his successor, Atahuallpa.
In the era of global conquest which followed, European colonizers were assisted around the world by the germs which they carried. A 1713 smallpox epidemic in the Cape of Good Hope decimated the South African Khoi San people, rendering them incapable of resisting the process of colonization. European germs also wreaked devastation on the aboriginal communities of Australia and New Zealand.

What It Means

This is a placeholder explanation generated by the low-overhead model. It interprets "When the Europeans arrived, carrying germs which thrived in dense, semi-urban populations, the indigenous people of the Americas were effectively doomed. They had never experienced smallpox, measles or flu before, and the viruses tore through the continent, killing an estimated 90% of Native Americans.
Smallpox is believed to have arrived in the Americas in 1520 on a Spanish ship sailing from Cuba, carried by an infected African slave. As soon as the party landed in Mexico, the infection began its deadly voyage through the continent. Even before the arrival of Pizarro, smallpox had already devastated the Inca Empire, killing the Emperor Huayna Capac and unleashing a bitter civil war that distracted and weakened his successor, Atahuallpa.
In the era of global conquest which followed, European colonizers were assisted around the world by the germs which they carried. A 1713 smallpox epidemic in the Cape of Good Hope decimated the South African Khoi San people, rendering them incapable of resisting the process of colonization. European germs also wreaked devastation on the aboriginal communities of Australia and New Zealand." in the context of "Jared Diamond, "Guns Germs and Steel" (1997) in "The Story Of... Smallpox – and other Deadly Eurasian Germs" Guns Germs and Steel Variables. Smallpox, PBS." to mean that wisdom is timeless.