Mysteries of Mankind

00:00:02 The earth does not easily yield its secrets.

00:03:09 A caveman.

00:05:47 undertook one of the most persistent efforts

00:07:58 into argon gas at a known rate over time.

00:10:05 for many scientists to accept.

00:12:19 Leopards are natural predators of chimpanzees.

00:15:07 What is most exceptional about a skeleton

00:17:14 possibly members of the same band.

00:19:25 by the thing I'm working on that it is not so much a thing

00:21:51 spewing ash across Tanzania's Serengeti Plain.

00:24:15 The emotional impact of the footprints is universal

00:26:17 Clothing holds the transmitter in place on the animal's back.

00:28:19 studies diet, using a scanning electron microscope and computer graphics.

00:30:23 a light plane from Nairobi brings expedition leader Richard Leakey

00:32:24 a species on the path that eventually led to modern humans.

00:34:01 about creationism versus evolution are going to have to get off the fence

00:36:25 we don't look anything like a hyena or a lion.

00:38:56 Into a scanning electron microscope, or SEM

00:40:53 after Homo erectus.

00:43:31 But there are more questions than answers.

00:45:46 who will probably use better techniques of excavation or better approaches.

00:47:57 Farming and the rise of great cities would await a later time.

00:50:36 Dr. Cann has studied Americans of European

00:52:29 To begin filling in the numerous blanks