American Exceptionalism

The concept that the United States is unique in the world, qualitatively different from and superior to all other advanced nations, blessed by God and the Constitution with a singular role to play in the history of the world.

Cassava, Manioc

A tropical root plant native to South America. Cassava, also known as manioc, is rare in its ability to thrive even in nutrient-poor tropical soils. In the wake of the Columbian Exchange, the cassava root was exported to Africa, where it became a staple crop able to sustain large populations that otherwise would not have been able to find enough calories to support themselves. Cassava remains a vital food source even today; it is estimated to be the world's third largest source of carbohydrates for human consumption.

Columbian Exchange

The rapid exchange of plants, animals, and diseases between the Eastern and Western Hemispheres after 1492.

Conquistador

A Spanish term for an explorer. Whoops, did we say "explorer"? We mean someone who steals land, abuses the natives, and generally takes no prisoners.

Divergent Evolution

A type of evolutionary biology in which characteristics that share common evolutionary origins grow more and more different over time.

Domesticated Animal, Domesticated Animals

Animals that have been physically or behaviorally altered to serve human masters through many generations of human control. Domesticated animals include many types of farm animals as well as pets.

Ecosystem, Ecosystems

An interdependent system comprised of a community of living things interacting with their environment. Humans tend to heavily shape the ecosystems they live in.

Infant Mortality

The death rate of children in the first year of life.

Life Expectancy

The number of years an individual in a particular society is expected to live, as indicated by socio-economic statistics. Life expectancy is frequently used as a measure of the relative healthfulness of a particular society.

Manifest Destiny

The concept, popular in the 19th century, that the United States was ordained by God to conquer the entire North American continent. First used by those who supported the annexation of Texas in 1845, the term later justified American settlement of the Great Plains and the West (and then the broadening of the American empire).

New World

A European term for the Western Hemisphere, which seemed brand new following Columbus' "discovery," in contrast to the Old World of Europe, Africa, and Asia—all of which had been known to Europeans for centuries. Of course, nothing about the New World was new to the Native Americans who had been living there for centuries.

Old World

A European term for the Eastern Hemisphere (Europe, Africa, and Asia), which was familiar to Europeans long before the "discovery" of the so-called New World (the Americas) in 1492.

Staple Crops

The primary source of nourishment in a traditional diet. Different societies have had different staple crops at different times; the staple crop of the Aztec Empire was corn, while the staple crop of the Irish peasantry was the potato.

Tectonic Forces

The geologic theory of plate tectonics explains the slow drift of the continents across the earth's lithosphere through millions of years.

Virgin-soil Epidemic, Virgin-soil Epidemics

An outbreak of a deadly disease among a population that has never before been exposed to it. Virgin-soil epidemics are among the most deadly events in human history, because the people who suffer them have no immunities or antibodies to the new diseases attacking their communities. After 1492, American Indian populations suffered virgin-soil epidemics of smallpox, influenza, measles, malaria, yellow fever, and other Old World diseases. The result was the worst population castastrophe in human history; as much as 90% of the pre-Columbian Exchange population of the Americas may have perished.