From lakes and grasslands with hippos and giraffes to a vast desert, North Africa's sudden geographical transformation 5,000 years ago was one of the planet's most dramatic climate shifts.
The transformation took place nearly simultaneously across the continent's northern half, a new study finds. The results will appear in an upcoming issue of the journal Earth and Planetary Science Letters.
http://www.livescience.com/28493-when-sahara-desert-formed.html
It was during the William Taft's<span> presidency that Congress passed the 16th Amendment to levy an income tax on the American people, and the 17th amendment, which allowed election of United States senators by popular vote.</span>
A society by which most food in gained by foraging
