Ziya Tong quotes:

Scientists believe that the invention of clothing in Africa was a key factor in allowing our ancestors to migrate into colder climates and to spread across the globe.

Actually, scientists don't know exactly how lice jumped from gorillas to our human ancestors. They speculate that we may have eaten them or perhaps slept in their nests.

Most of what we know about human evolution comes from these: the fossilized bones of our ancestors. With their help, we've traced our evolution from small furry creatures to the big-brained beings we've become today. But bones can't tell us everything.