Science Struck
Science Struck: Facts About the Cenozoic Era and Its Life Forms
Describes the different periods, epochs, and stages of the Cenozoic Era and the events that took place in them. Looks at geology and tectonic plate movements, climate, flora and fauna, and the emergence of mammals as the dominant life...
Khan Academy
Khan Academy: Collective Learning (Part 4)
In the final essay of a four-part series, David Christian explains how advances in communication and transportation accelerated collective learning.