Building Blocks: Mass Extinctions
The ultimate example of an environmental change leading to the termination of a species is what's known as a mass extinction.
Building Blocks: Ancient Fossils, Modern Technology
As scientists work to answer vexing questions about the origins of life, they examine the fossilized remains of the primitive life forms which at one time populated early Earth. The challenge in doing this is not only a function of the age of the fo...
From Days Before Time: Early Inhabitants of North America
Long before Europeans venture out into the waters of the Atlantic to see what lay beyond the boundaries of their continent; tribes of Native Americans inhabit the land now known as North America. At first the animals and plants of the land provide t...
Building Blocks: Role of Evolution in Early Life
The ability to adapt to changing or difficult conditions is clearly necessary if an organism is to be biologically successful.