More than 100,000 years ago, the ostrich eggshells and crystals collected by humans in the interior of South Africa revealed the cultural evolution of early humans and demonstrated technological innovations off the coast of South Africa at that time. Pliny the Elder of ancient Rome once said, “Ex Africa semper aliquid novi”-there is always something new in Africa. Wilkins et al[1]An example of this is the report on “Nature” about materials excavated in a rock shed in inland northern South Africa. The objects they found indicate that our current view of the birth of early human cultural innovation has to be changed. In the 1980s, researchers put forward new ideas about the origin of our species-Homo sapiens. These new ideas are based on newly developed technologies, such as optical luminescence dating (OSL), which can accurately date ancient sites as far as 50,000 years (50,000 years is the upper limit of radiocarbon dating). These views are also rooted in the study of genetic diversity. The evidence comes from mitochondria, the organelles that provide energy in cells. Mitochondrial DNA is inherited from the maternal line. Some mitochondrial DNA does not code for proteins, and tracking the rate of change of mutations accumulated in this DNA over time can provide a “molecular clock.”A study on existing human mitochondrial DNA concluded that we all have a certain nearest common ancestor, nicknamed “mitochondrial Eve” (mitochondrial Eve), she may be African, living 200,000 years ago[2]. By 1988, researchers were still arguing[3]Whether the question of the origin of modern Homo sapiens has been answered, some people subsequently put forward the theory called “Out of Africa 2”. The theory believes that our direct ancestors evolved in Africa alone, and some of their offspring left the African continent at some time after about 50,000 years ago, distributed across the world, and interbred with ancient humans (close relatives of humans) in Eurasia. Important sites related to modern human fossils in Africa have been re-dated, and innovative technologies have been discovered in some early sites. This shows that about 200,000 years ago or even earlier, Africans belonged to modern humans in anatomical and cultural sense. But usually they mainly rely on stone tools, the same as those made by their ancient human cousins (Neanderthals and Denisovans) in Eurasia at the same time. In sub-Saharan Africa, this technology is considered the Mesolithic Age (MSA). In Eurasia and North Africa, similar types of artifacts belong to the so-called Middle Palaeolithic.Both technologies can be traced back to approximately 300,000 to 30,000 years ago[4].Current evaluations of archaeological, fossil, and genetic data confirm these views[5]It also supports Africa’s outstanding role in the later stages of human evolution. Archaeological evidence shows that signs of modern humans outside of Africa are related to the beginning of the late Paleolithic period (about 50,000 to 40,000 years ago). It is defined as a series of technological innovations: movable art, and eventually cave paintings and carvings; the original non-stone tools (such as bone or horn); the earliest known jewelry; and the occurrence of lifestyle and resource acquisition Evidence of major changes. These evidences that were once regarded as “human revolution” are a qualitative leap in cultural evolution and can only be related to modern people in the true sense. Unsurprisingly, the researchers tried to find similar evidence in sites from the Middle Stone Age and Middle Paleolithic Age in Africa. Now that modern people of anatomical significance have lived there, where is the evidence corresponding to the late Paleolithic period? But throughout Africa, archaeological evidence is fragmentary. There are some late Paleolithic elements, but they sometimes disappear, appear and disappear in one area, and only reappear in other places after thousands of years. Part of the problem is that only a small number of African regions have been studied in detail, mainly at the northern and southern ends of the continent with a temperate climate (Figure 1). Other places that have been investigated in depth are places where researchers have reason to expect to find ancient relics, such as where fossils and stone tools have been exposed due to erosion of the natural landscape. These important locations are located in the Gregory Rift Valley in Ethiopia, Kenya and Tanzania[6]And South Africa’s dolomite limestone caves, the latter is known as the cradle of mankind[7]. But these two areas contain records of the very early stages of human evolution. Mesolithic records are most commonly found in rock sheds and caves. Figure 1 | Some African archaeological sites related to the Mesolithic Age. Certain sites mainly located in coastal areas (cross-hatched) have a long history of excavation, and they help reveal the evolution of early human populations. In contrast, the surveys of the listed inland points are only the past three decades.Research on these inland sites reveals important technological innovations in the Mesolithic Age (MSA) from 300,000 to 30,000 years ago[8-14]. Wilkins et al[1]The report found fragments and crystals of ostrich eggshells (OES) in the rock shed on Ga-Mohana Mountain, which indicates that humans had collected unusual objects at least 105,000 years ago (105 ka). All these findings show that MSA’s innovations are diverse in time and space, and illustrate the necessity of investigating and studying other parts of the African continent. LSA: Late Stone Age; after 40,000 years ago. People have been reluctant to investigate new areas, probably because it is easier to continue working where results have already been produced, and there is no need to go to other places at the risk of nothing. Figure 1 shows that the MSA site is far from the traditional research area that has been surveyed in the past 30 years.The evidence from the excavation work is surprising[8-15], From early ostrich eggshell beads and carved shell containers, to spear-shaped bones and stone tools, and possibly even bows and arrows . However, a single African site has never discovered all the technologies of the late Paleolithic period in Eurasia. In South Africa, researchers mainly learn about MSA through coastal sites, including the Cresses River and Blombos Cave.The builders of these sites used a lot of shellfish and fish[15]. This has led some people to conclude that marine food has played an important role in the evolution of human brain and behavior, and in general terms have resulted in the true modern human population. But what can we know about the inland Africa in the Mesolithic Age? Wilkins and others reported that there were some unexpected discoveries at a site on Ga-Mohana Mountain (Figure 1)-on the edge of the Kalahari Desert 665 kilometers from the coast. Some of these items are presumably used for decoration, and may represent an early ritual symbolic act . The author reports a long list of archaeological discoveries, including a limestone layer called travertine, which was dated using uranium-thorium analysis.In addition, the travertine allowed the author to reconstruct the past environment, showing the existence of multiple wet and lush “green Kalahari” periods, reminiscent of the Sahara[16]And arab[17]There was a period of lush greenery. Wilkins et al. used optical luminescence dating to date some sediments. A sedimentary layer on the Ga-Mohana Mountain is approximately 105,000 years old and contains 42 charred ostrich eggshell fragments and 22 calcite crystals. This may be a material storage warehouse with no signs of deliberate changes to the contents (burning is considered to occur naturally). The author reports that such crystals have never been found in southern African sites over 80,000 years old. Wilkins and colleagues systematically studied all the reasons these objects might be there. After excluding all possible natural explanations, just as forensic researchers exclude other possible situations in their investigations, they only have one conclusion left- People specially collected such non-practical items . Researchers speculate that they were piled up for some symbolic purpose; this is a sign that their collectors are modern humans in the sense of behavior. Are there similar discoveries in other early African sites? In western South Africa, many charred and carved fragments of ostrich eggshells were unearthed in Diepkloof Cave. They are about 60,000 years old.In the Diepkloof cave[8]And Mount Ga-Mohana, These shells may be remnants of ancient water containers, which are common in the ruins of later times.If so, their main role may also be functional rather than symbolic . Given the age of the objects discovered by Wilkins et al., it may not be surprising that the ostrich eggshell was undecorated (as in the Diepkloof cave) or not made into beads. These situations were about 50,000 years ago in Magubike, Tanzania.[9]Rock Shed and Panga ya Saidi[10,11]It just started to appear; Panga ya Saidi is a group of caves located off the coast of Kenya, with artifacts that span about 78,000 years. Wilkins and colleagues said their findings indicate that it is imperative to investigate sites in the interior of southern Africa. In East Africa, I want to say that we have the opposite problem, because archaeologists have almost never investigated coastal sites from the Stone Age. In fact, Panga ya Saidi may be the first East African coastal site ever discovered that contains a time series spanning such a long Stone Age. The Mesolithic residents there made ostrich egg shell beads and snail shell beads, used ochre as a pigment, and collected resources in a forest environment that was completely different from the grassland. (Grassland is assumed to be the norm in the Mesolithic Age). The purpose of the excavation of Panga ya Saidi is to study the trade links of the entire Indian Ocean, and a large number of Stone Age deposits were discovered by accident. Even the Mesolithic inland sites in East Africa-once thought to be well understood-have unexpected gains.For example, at the Olorgesailie site in Kenya[12], People transport stone materials long distances, and use ocher to make pigments.In Katanda, Democratic Republic of Congo, there is a large catfish living in a river, and people nearby made bone forks and other fishing gear[13]To make use of these rich river resources. In the late Stone Age (LSA; after 40,000 years ago), the ability to pierce a fish with a spear was common, but its appearance in the Mesolithic was unexpected. Mumba Cave in Tanzania[14]It is one of the first excavation sites in East Africa focusing on the Mesolithic Age. The excavation was led by Norwegian archaeologist Margit Kohl-Larsen in the 1930s. At the same time, her husband Ludwig was collecting ancient human fossils in Littleley near Lake Eyasi a few kilometers away; later British archaeologist Mary Leakey and colleagues discovered the footprints of ancient humans in Littleley, 3.75 million years ago.They are produced by bipedal individuals and are the oldest ever discovered[18]. Mumba contains Mesolithic sediments, with late Stone Age sediments above it.There is no sign of any technological mutation; innovative technologies existed in the Mesolithic Age, and these technologies hardly changed in the late Stone Age[14]. Wilkins et al. emphasized, It is necessary to conduct a continent-wide examination of the evidence of innovation in the Mesolithic Age and beyond . Only in this way can we understand the cultural evolution of our recent common ancestors.Homo sapiens[5]The fossil record of Africa shows that there does not seem to be any single technological and social development model over time. Investigation and excavation of little-known areas will help clarify what made our direct ancestors become truly modern humans in the biological and cultural sense. Cover source: Pixabay references [1] Wilkins, J. et al. Nature 592, 248C252 (2021). [2]. Cann, RL, Stoneking, M. & Wilson, AC Nature 325, 31C36 (1987). [3]. Stringer, CB & Andrews, P. Science 239, 1263C1268 (1988). [4]. Willoughby, PR The Evolution of Modern Humans in Africa: A Comprehensive Guide (Altamira, 2007). [5]. Bergstr m, A., Stringer, CB, Hajdinjak, M., Scerri, EML & Skoglund, P. Nature 590, 229C237 (2021). [6]. Gregory, JW The Great Rift Valley (Murray, 1896). [7]. Bonner, P., Esterhuysen, A. & Jenkins, T. (eds) A Search for Origins: Science, History and South Africa’s Cradle of Humankind (Witwatersrand Univ. Press, 2007). [8]. Texier, P.-J. et al. Proc. Natl Acad. Sci. USA 107, 6180C6185 (2010). [9]. Miller, JM & Willoughby, PRJ Hum. Evol. 74, 118C122 (2014). [10]. d’Errico, F. et al. J. Hum. Evol. 141, 102737 (2020). [11]. Shipton, C. et al. Nature Commun. 9, 1832 (2018). [12]. Brooks, AS et al. Science 360, 90C94 (2018). [13]. Yellen, JE, Brooks, AS, Cornelissen, E., Mehlman, MJ & Stewart, K. Science 268, 553C556 (1995). [14]. Bushozi, P., Skinner, A. & de Luque, L. Afr. Archaeol. Rev. 37, 293C310 (2020). [15]. Langejans, GHJ, Van Niekerk, K., Dusseldorp, GL & Thackeray, JF Quat. Int. 270, 80C94 (2012). [16]. Larrasoa a, JC, Roberts, AP & Rohling, EJ PLoS ONE 8, e76514 (2013). [17]. Petraglia, MD, Parton, S., Groucutt, HS & Alsharekh A. Quat. Int. 382, 1C7 (2015). [18]. Leakey, MD et al. Nature 262, 460C466 (1976). The original article was published under the heading Early humans far from the South African coast collected unusual objects in the News and Views section of Nature on March 31, 2021.
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