Quick facial thinking
I have always found it remarkable that the average person can identify probably thousands of individuals by face “Face Smarts,” (SN: 10/6/12, p. 20) and perhaps hundreds by voice, as well as some just by their gait. Clearly such identification at a distance must have been a crucial survival advantage during our evolution; this unfortunately suggests to me that the larger threat to earlier humans was not lions or tigers and the like, but rather other members of our own species.
Peter Benson, North Oaks, Minn.
Timing human history
“No home for Homo sapiens” (SN: 10/20/12, p. 9) says that the Khoisan separated from the rest of humanity “at least 100,000 years ago.” For much (if not all) of that