1.   The human ancestors, in other words, were not even drop-outs, they were throw-outs.

2.   The unique character of the clicking sounds in their language has persuaded some researchers that the Khoisan people are directly descended from the most primitive human ancestors.

3.   An alternative theory, known as regional continuity, holds that the earliest human ancestors arose in Africa and spread around the world more than a million years ago.

4.   As human ancestors foraged in the Pleistocene, mental organs formed under the pressure of natural selection, Pinker said.

5.   As Leakey reported in the journal Nature last week, her team had discovered what is probably the oldest direct human ancestor ever identified.

6.   At the time, the discovery established that human ancestors had begun walking upright much earlier than previously thought, long before the evolution of larger brains.

7.   But nothing is more evocative of human ancestors as living, walking people than a trail of footprints.

8.   But nothing is more evocative of human ancestors than living, walking people than a trail of footprints.

9.   But the scientists already know enough, they say, to be excited about what the fossils may tell them concerning the anatomy and evolution of early human ancestors.

10.   --DR. OWEN LOVEJOY, a paleontologist, on the discovery of fossils of the oldest human ancestors.