Oldest poison pushes back ancient civilization 20,000 years

[CBS]  The late Stone Age may have had an earlier start in Africa than previously thought -- by some 20,000 years. A new analysis of artifacts from a cave in South Africa reveals that the residents were carving bone tools, using pigments, making beads and even using poison 44,000 years ago. These sorts of artifacts had previously been linked to the San culture, which was thought to have emerged around 20,000 years ago.