New research at a rock shelter on the edge of the Kalahari Desert in South Africa disputes the assumption that modern human origins and complex behaviors were limited to coastal environments. An unusual collection of artifacts, more than 100,000 years old, suggests this inside homo sapiens they were as innovative as their coastal cousins.
There is a widespread belief that the origins of modern humans and modern human knowledge can be located in southern Africa. Because many of the archaeological sites related to early human activity are located on the coast, experts assumed that homo sapiens they also evolved their symbolic and technological behavior in that region. But a new study published in the journal The nature paints a very different picture.
One of the stone tools excavated from Ga-Mohana Hill North Rockshelter. (Credit: Jayne Wilkins)
The oldest evidence for modern people in the Kalahari desert
An international team of scientists explored Ga-Mohana North Rockshelter, a site overlooking the Kalahari Desert Savannah and more than 600 km (370 miles) inland. The study’s lead author, Dr Jayne Wilkins of Griffith University’s Australian Center for Human Evolution Research, explained the significance of the discovery in a University of Innsbruck press release, saying:
“Our findings in this shelter show that models that are too simplified for the origins of our species are no longer acceptable. Evidence suggests that many regions of the African continent were involved, with the Kalahari being only one […] There have been very few well-preserved archeological sites in South Africa that can tell us about the origins of Homo sapiens far from the coast. A rock shelter on the hill Ga-Mohana which is above an expansive savannah in the Kalahari is one of these sites. ”
According to the press release, the scientists’ work also provided “the oldest evidence for modern people in the Kalahari desert in Africa.”
Archaeological excavations on Ga-Mohana Hill North Rockshelter were early evidence for the complex homo sapiens behaviors were recovered. (Credit: Jayne Wilkins)
Looking at “Miniature Clocks”
An analysis of the site and the artifacts found at the stone shelter provides evidence that the behavioral patterns of homo sapiens on the spot it was made parallel to what was happening on the coast 100,000 years ago. The main evidence comes from a collection of calcite crystals and fragments of ostrich eggshell, which researchers believe could have been used as a container for storing water.
Using optically stimulated luminescence (OSL), the team determined the age of the various archaeological strata in which the artifacts were found and gave the objects 105,000 years old. Michael Meyer, head of the OSL Laboratory at the Institute of Geology at the University of Innsbruck and the geologist who conducted the OSL analysis, explained the technique:
“This method exploits the signals of natural light that accumulate over time in quartz and feldspar sedimentary grains. You have to think of each grain as a miniaturized clock. Under controlled laboratory conditions, we can read this natural light or the so-called luminescence signal, which in turn informs us about the age of the archaeological sediment layers. The more light, the older the sediment. ”
The researchers also noted that the climate of the Kalahari Desert was much wetter – as evidenced by the tuff formations (a type of limestone) found around the rock shelter. Uranium-thorium dating of these features provides an age of between 110,000 and 100,000 years – at the same time that ancient people lived on the site.
A collection of Kalahari crystals – symbols of a very ancient sacred palace?
At first, the collection of 22 calcite crystals presented something mysterious, because, unlike the ostrich shell pieces, the researchers could not see an obvious utilitarian purpose for them. Then they decided it was a clue. Dr. Wilkins said, “Our analysis indicates that the crystals were not placed in deposits by natural processes, but were deliberately collected objects, probably related to spiritual beliefs and rituals.”
Crystals collected early homo sapiens in the southern Kalahari 105,000 years ago. (Credit: Jayne Wilkins)
Co-author of the study, Dr. Sechaba Maape of the University of the Witwatersrand agrees and said that “This is remarkable given that the site continues to be used for ritual activities today.” The archeological team is aware that Ga-Mohana Hill still has a spiritual significance for the local communities and they say that it is trying to limit its impact on the local use of the rock shelter site. “Leaving no visible marks and working with the local community is essential to the sustainability of the project,” said Dr. Wilkins, who is also important. Homo sapiens in the Kalahari. ”
Archaeological site of a stone shelter in the Kalahari Desert of South Africa. More than 100,000 years ago, people used the so-called Ga-Mohana Hill North Rockshelter for spiritual activities. (Credit: Jayne Wilkins)
The article, entitled “Innovative homo sapiens behaviors 105,000 years ago in a wetter Kalahari, ”the journal said The nature.
Top image: Calcite crystal being excavated from 105,000-year-old deposits at Ga-Mohana North Rockshelter in the Kalahari Desert in South Africa. Source: Jayne Wilkins
By Alicia McDermott