The findings come from analyses of dust blown west from Africa and dropped into the Atlantic Ocean. Researchers sifted through 30,000 years of dust and ocean bottom muck retrieved with ocean drilling ships. The changing levels of windblown dust in the ocean sediments provide scientists with clues to Africa's climate and how it has changed over time. Simply put, a lot of dust means drier conditions and less dust means a wetter environment. So the people that were living on Sahara desert at the time either died from the weather changing or they survived from living in a different way than before. Getting food differently and started to wear different clothing.