Human evolution

The world’s oldest mattresses have just turned up in South Africa

The Economist, Dec 10th 2011 | http://www.economist.com/node/21541380

SETTING up home in the modern world means acquiring some furniture—particularly a bed. And things were not so different 77,000 years ago, according to the latest research on the behaviour of early man in South Africa. Caves in that country have yielded a lot of discoveries about how Homo sapiens made the transition to modernity. That he liked to sleep on a comfortable mattress is the latest.

That, at least, is the conclusion of a study just published in Science by Lyn Wadley of the University of Witwatersrand and her colleagues. The bedroom in question is in a natural rock shelter called Sibudu, 40km (25 miles) north of Durban. As is often the case with such shelters, it was not occupied continuously. Dr Wadley has found evidence for at least 15 different occasions when it acted as a home, with periods in between when it was abandoned. Each occupation left debris behind, though, and as this accumulated, the cave floor gradually rose.

These insecticidal leaves would have discouraged fleas and other biting arthropods—and possibly mosquitoes, too. Dr Wadley thus thinks that what she has found are mattresses on which the inhabitants of Sibudu slept. They may also have walked and worked on them, in a way similar to the use of tatami in modern Japanese houses.The most interesting layer is the oldest. It is this stratum that dates from 77,000 years ago. Among the things Dr Wadley’s team found in it were sheets of plant matter several square metres in area, themselves divided into layers. The lower part of these layers, compressed to a thickness of about a centimetre, consists of sedges, rushes and grasses. The upper part, just under a millimetre thick, is made of leaves from Cryptocarya woodii, a tree whose foliage contains chemicals that kill insects.

Other evidence, too, suggests pests were a problem. More recent mattress-like layers of plant matter at Sibudu, dating from between 73,000 and 58,000 years ago, show signs of having been burned. That was probably a regular procedure, again undertaken to get rid of unwanted creepy crawlies.

The upshot is another piece of evidence of how, around this period, humans were creating a range of hitherto unknown artefacts. Adhesives, arrows, sewing needles, ochre-decorated pictograms and jewellery made from shells are all contemporary with Dr Wadley’s finds. And stone tools became more delicate and sophisticated during this period. It was also a time when humanity went through several drastic shrinkages of population, which probably applied selective pressures that forced the pace of evolution. The origins of modern, consumer-good-loving humanity might thus be illuminated by this scene of ancient domestic bliss.