Scientific evidence suggests that modern humans Homo sapiens evolved on the Cape south coast, somewhere between Saldanha Bay and East London. This founder group was part of a population that comprised an estimated mere 20 000-10 000 individuals scattered across the whole of Africa. Indeed, had there been conservationists then, they have would classified humans as an endangered species.
Sometime during a prolonged ice-age period when conditions over most of Africa were considerably colder and drier than present, a tiny population of these hunter-gatherers – estimated from ancient DNA to amount to no more than around 600 breeding individuals – survived somewhere on the continent, and went on to be the ancestors of all of humanity. That “somewhere” appears to be on the coastline of the then exposed Agulhas Bank. The “sometime” was between 200 000 and 140 000 years ago.
The Agulhas Bank or Palaeo-Agulhas Plain, the continental shelf (rust-brown) that was exposed to a greater or lesser degree during the long ice age period when modern humans evolved on the Cape south coast. Also shown are the major archaeological sites that have yielded evidence of modern human behaviour between 200 000 and 50 000 years ago. PP = Pinnacle Point near Mossel Bay. Graphic courtesy of Eric Fisher (Arizona State University).
Our human lineage was confronted with the problems of surviving under difficult and harsh conditions. Fortunately, the ice-age environment of the Cape South Coast was differentiated by the persistently warm Agulhas Current from the rest of Africa. The coastal environment, which included the then exposed Agulhas Bank or Palaeo-Agulhas Plain, which was a consequence of lower sea levels during glacial times, provided an array of resources that were capable of sustaining humans.
A fossilised trackway of a human footprint made on a sand dune more than 100 000 years ago. The footprint, the oldest known one of a modern human, is preserved in cemented sand dune at Brenton-on-Sea, near Knysna. Photo: Charles Helm.
This included an abundance of shellfish, fish, and marine mammals; a mosaic of fynbos, grassland and thicket vegetation which offered year-round access to edible bulbs, fruits and wood for fuel and weapons. In addition, abundant potable water together with a fertile, grassy coastal plain that supported a migratory system of large mammals including wildebeest, zebra and several extinct giant grazers provided an additional source of protein.
Foraging and harvesting these resources, would have required considerable intelligences not previously fully manifested in the human lineage. Harvesting of shellfish along the wave-battered Cape coast requires knowledge and an understanding of the tidal rhythms, sea conditions and the zonation and location of different species. Gathering bulbs and berries requires knowing which species provide the best nutrition, and when and where they are most abundant (the Cape has the richest bulb flora worldwide, so efficient foraging must have required considerable plant-identification skills to distinguish edible from poisonous, tasty from astringent, and nutritious from insipid). Hunting of plains game required co-operative skills and reasonable weaponry to bring down fleet-footed and large animals.
Caves in coastal settings, such as the famous Klasies River cave (left) provided shelter adjacent to a rich marine intertidal resource. A relatively young (ca 4000-year-old) midden comprising mainly alikreukel (Turbo samarticus) shells near Blombos Cave. Photos by Richard Cowling
In short, the human brain must have undergone a massive rewiring to master the technical and social skills required for survival on the windswept plains of the ice-age south Cape coast.
The hugely diverse bulb flora of the Cape coast provided foragers with a year-round supply of carbohydrate. On the left is bobbejantjie (Babiana sp), so named because it’s underground corms are a favoured food of the chacma baboon (photo: Jan de Vynck). On the right is a woman of Khoe-San ancestry harvesting bulbs in the Still Bay area using a traditional digging stick (photo: Elzanne Singels).
Archaeological evidence provides insightful glimpses into this cognitive and cultural evolution. In addition to producing evidence of shellfish harvesting, research at Blombos Cave near Still Bay yielded engraved ochre dating back some 70 000 years, evidence of the symbolic creativity inherent in art.
This research debunked the myth that the human cultural revolution occurred in Europe, sometime after modern humans migrated out of Africa. Curtis Marean’s research group, which has been excavating Pinnacle Point for more than a decade, pushed this date for cultural innovation back to 165 000 years ago. They also unearthed seashells that had been used as ornaments for decorating cave sites, dating to 110 000 years ago. And most intriguingly, they showed that as early as 160 000 years ago, humans were able to beneficiate silcrete sediment, using a complex process of heat treatment, in order to produce the finely crafted stone tools required for more effective and efficient hunting, fishing, cutting and cleaning.
All these innovations required complex cognitive skills, such as novel associations between unrelated phenomena that yield new products of artefacts and most importantly language and co-operative behaviour and sharing of resources amongst themselves. In short, the hallmarks of human culture that set us apart from all other hominins.
The exciting implications of this research is that modern humans Homo sapiens evolved on our coastline from a tiny founder population that migrated into the rest of Africa and then, into Eurasia between 40 and 45 000 years ago then to the Americas. The notion that all of humankind has its origins on our coastline is a compelling and powerful metaphor for a nation so painfully divided along racial lines.
Furthermore, the fact that this rewiring of our brains was likely underpinned by the need to comprehend and exploit the diverse marine and land biotas of the Cape palaeoscape is a testament of the fundamental role of biodiversity in ensuring our persistence as a species. These are powerful narratives for social and environmental sustainability in a world facing unprecedented crises.
The Greater St Francis area is blessed with a wealth of archaeological features showcasing the evolution of hominins (Homo erectus and H sapiens) over the past million years. Shown here are the palisade of fish traps at Thyspunt (top), a Middle Stone Age workshop for making stone tools in the Cape St Francis Nature Reserve (bottom, left), and a Middle Stone Age shelter under a fossilised kershout-milkwood forest (note the remnant tree stumps) with numerous stone tools on the surface of an ancient, reddish soil (photos: Robin Moulang (top) and Richard Cowling (bottom).