Human foot bones from Klasies River main site, South Africa.

The caves at Klasies River contain abundant archaeological evidence relating to human evolution in the late Pleistocene of southern Africa. Along with Middle Stone Age artifacts, animal bones, and other food waste, there are hominin cranial fragments, mandibles with teeth, and a few postcranial remains. Three foot bones can now be added to this inventory. An adult first metatarsal is similar in size and discrete anatomical features to those from Holocene burials in the Cape Province. A complete and well-preserved second metatarsal is especially long and heavy at midshaft in comparison to all Holocene and more recent South African homologues. A large fifth metatarsal is highly distinctive in its morphology. In overall size, these pedal elements resemble specimens from late Pleistocene sites in western Asia, but there are some differences in proportions. The fossils support earlier suggestions concerning a relatively high level of sexual dimorphism in the African Middle Stone Age population. Squatting facets on the two lateral metatarsals appear to indicate a high frequency of kneeling among members of this group. The new postcranial material also underlines the fact that the morphology of particular skeletal elements of some of the 100,000-year-old Klasies River individuals falls outside the range of modern variation.

New human teeth from Middle Stone Age deposits at Klasies River, South Africa.

Since 1984, the main site at Klasies River has been re-investigated. Human remains, animal bones and stone artefacts have been collected from the LBS, SAS and other stratigraphic members, and these discoveries help to establish the antiquity of anatomically near-modern populations practicing a Middle Stone Age way of life on the southern coast of Africa. Several teeth found in the lower SAS levels in 1989-1991 can be matched in recent South African populations. Two complete upper molars representing one individual have crowns that are relatively short mesiodistally. These specimens are small in comparison to black South African homologues, but MD and BL dimensions fall close to the averages for San burials. This evidence confirms that several of the Klasies individuals have very small molars, while others have cheek teeth that are close to the upper limits for size variation in recent Africans. The new material is in keeping with the view that sex dimorphism within this Middle Stone Age population may be pronounced.

Southern Africa and modern human origins.

This paper argues that southern Africa was a remote part of the Old World in the late Pleistocene (125-10 ka ago). Because of this isolated position there was continuity without significant replacement in the resident population. Isolation and the relatively recent spread of agriculture to the region has allowed a section of this population to survive into the present. They are the Bushmen (San). Studies of geographic patterning in conventional genetic markers and mitochondrial DNA indicate that the Bushman clade has a long evolutionary history in southern Africa. Estimates of more than 100 ka for the continued presence of this population in the region are supported in archaeological investigations of sites with long sequences such as Klasies River main site and Border Cave. Human remains dating to the earlier part of the late Pleistocene have been recovered from these sites and the samples form a morphological series with the Klasies River remains possibly 20 ka older than those from Border Cave. There is no fossil record for the later Pleistocene, however, at a period when selection for a gracile morphology may have been pronounced. The cultural associations in the earlier late Pleistocene are with the Middle Stone Age. Expressions of cultural 'style' and the occurrence of similar artefact design types in the Middle and Later Stone Ages can be interpreted with reference to the ethnographic present. Temporal continuity can be shown in the geographical distribution of stylistic markers and this suggests participation in a shared cognitive system.(ABSTRACT TRUNCATED AT 250 WORDS)