Britain's Industrialization     The Industrial Revolution was an extended period of economic growth and change brought about by the application of mineral energy and t...

Insect Colony Movement     In general, colonies of social insects such as bees or ants move either to change nesting sites when the current site deteriorates in quality,...

Early Food Production in Africa   Farming appeared in Africa by 5000 B.c.E. Eventually, several different styles of food production developed. These variations were caused by ...

How Fossils Map the Past     Only a tiny fraction of the organisms that have lived during the geologic past have been preserved as fossils.Normally the remains of an ani...

Parental Care by Frogs Only an estimated 10 percent of anuran (frog and toad) species provide any kind of parental care. But within this 10 percent there is very great diversity ...

Jazz   Jazz music, an art form original to the United States, originated in the southern city of New Orleans at the turn of the twentieth century. It combined the elements of ...

Erratics and Drift   In the nineteenth century, scientists theorized that glaciers (ice sheets) covered much of Earth's surface during an ancient very cold period known as the...

Mars's Disappearing Atmosphere   For about the first billion years of its life, Mars was probably a watery planet. There are signs of past water in surface features, such as d...

The Early Iron Age     During the Bronze Age (roughly 3300-1200 B.C.E. in the Middle East), civilizations were limited in their use of iron. Most iron occurred not in ...

重复时间 2024-06-18 2024-09-28 2025-02-22 Equestrian Portraits in the Eighteenth and Nineteenth Centuries     It was common for European rulers from the eighteenth ...