I was looking at some of my old photographs over the weekend. While my wife was always good at putting hers in albums, mine filled shoeboxes instead. (Another biological difference between the sexes? Bachelors just don't waste time putting photos in books?) So we were going through them, trying to put them in albums and I was having trouble figuring out whether one was older than another. This was way before jpegs, of course, and a couple years before K-Mart started stamping the backs with the date of processing.

Was it 1969 or 1970? Was I two or three? It was frustrating not knowing, for sure, but made less so by something I read last night in The Economist: palaeo-anthropologists are having a hard time dating the world's oldest attempt at art. Are some stone-age shells that were found in Africa 74,000 years old or 91,000? We're talking about a difference of nearly 20,000 years here folks! Forget K-Mart date stamping, forget even asking your grandmother for help.

The shells, which were strung together in the shape of a necklace and painted with ochre, turned up in Morocco recently but have also been found in South Africa, as well. Because of this, some researchers think the shells aren't art, but rather the first form of currency.

From the article:

Stone-age South Africans, like their northern cousins, could have chosen any one of hundreds of shell shapes to make into beads, yet they adopted essentially the same fashion. The immense distance between the two ends of the continent makes an ancient African exchange system appear improbable. Then again, a chance predilection for the same beads is unlikely as well.