Scientists Find Three Kinds of Early Humans Living Together in South Africa

The drimolen fossil site. (Andy Herries)

By Brian Handwek. First published on SmithsonianMag.com

Scientists studying the roots of humanity’s family tree have found several branches entangled in and around a South African cave.

Two million years ago, three different early humans—Australopithecus, Paranthropus, and the earliest-known Homo erectus—appear to have lived at the same time in the same place, near the Drimolen Paleocave System. How much these different species interacted remains unknown. But their contemporaneous existence suggests our ancient relations were quite diverse during a key transitional period of African prehistory that saw the last days of Australopithecus and the dawn of H. erectus’s nearly two-million-year run.

“We know that the old idea, that when one species occurs another goes extinct and you don’t have much overlap, that’s just not the case,” says study coauthor Andy Herries, a paleoanthropologist at La Trobe University in Australia.

Homo erectus cranium with stylized projection of the outline of the rest of the skull. (Andy Herries, Jesse Martin and Renaud Joannes-Boyau)

Three Species, One Place

Australopithecus africanus is the most primitive of this trio. The lineage dates to 3.3 million years ago and combines human features with ape-like attributes including long, tree climbing-arms. Despite these intermediate features, Australopithecus’s exact relation to modern humans remains unknown. The species is thought to have died out around 2 million years ago.

Paranthropus robustus, an offshoot of the human family tree not considered a direct human ancestor, is known for large, powerful jaws and teeth that could pulverize a diet of nuts, seeds, roots and tubers. Paranthropus lived from perhaps 2 million years ago (the remains described in this study are the earliest known) until about 1.2 million years ago.

Homo erectus was the first ancestor of modern humans to have human-like body proportions and the first to appear outside of Africa. The species appeared in what is now the nation of Georgia 1.85 million years ago and survived in some Indonesian enclaves until as recently as 117,000 years ago. It’s generally believed that they first evolved in Africa, and the cranium find described at Drimolen would push back their earliest-known occurrence anywhere in the world by more than 100,000 years.

“It’s an excellent paper, and it looks quite convincing,” says Fred Spoor of the Natural History Museum, London. “It would have been ideal if there was more of the cranium, but I think they make a very good case that it’s Homo and that the closest affinities are probably with erectus. And that would make it quite likely the oldest Homo erectus-like thing.”

The Drimolen excavations and excavated fossils. (Andy Herries)

“I have no doubt that they have something that is of the genus Homo,” adds Rick Potts, a paleoanthropologist and head of the Smithsonian’s Human Origins Program. But Potts notes that the incomplete skull doesn’t show all the telltale features that would characterize it as Homo erectus or some other relative. Furthermore, the cranium belongs to a 2- or 3-year-old child, for which comparisons are scarce. “I’m not 100 percent sure that they have Homo erectus. And that would be one of the really interesting parts of the study, because if they do have Homo erectus then it is the earliest known in the world.”

Out of Africa, or Within Africa?

If Herries and colleagues are correct that they have found Homo erectus, the early dates of the find pose an intriguing question: How did the species arrive in South Africa?

One possibility is that H. erectus originated here and later spread to East Africa and then out of the continent. However, Herries says that the discovery of the oldest-known bones doesn’t necessarily mean H. erectus started in this locale. Perhaps they migrated to the area.

“It seems that Homo erectus and Paranthropus and stone tools all suddenly occur in South Africa at this point,” Herries says. “This suggests that we’ve got movement into the region, and I think it’s really part of this same sort of story. We talk about 'Out of Africa' a lot, but the hominids didn’t know they were going out of Africa. They were just moving.”

Herries and colleagues cite some evidence for non-hominid migrations that may lend weight to this theory. An extinct prehistoric zebra and springbok appear at South African sites during this same time, suggesting some environmental factors spurred their relatively sudden migration into the region from regions further north where they are known to have lived earlier.

It’s a question of putting our ancestors in their place ecologically, Potts says, which drives much of his work on hominin evolution. “We think a lot about what’s going on with other mammals when looking at explanations of human evolution,” he says. “This period around 2 million years ago is one of prolonged, very high climate variability in Eastern Africa. I think that’s just the right conditions for animals to be moving around to track different environments.”

If it was a migrant, H. erectus would have moved into an area that was already occupied by other ancient hominids and shared the same landscape with them for a significant time. “The fact that in a small area in South Africa you have not just three species but three different genera, … at the same time is neat,” says Spoor, who this week published a study modeling the brains of the famed hominid Lucy and her kin. “This will certainly put Drimolen back on the map.”

“We talk a lot about [diverse species coexisting] with Neanderthals, modern humans, and Denisovans, and we can see that with DNA, but we don’t have that ability with this earlier stuff,” adds Herries. “I’m sure it happened and this may be one of the first instances where we can really see it.”

La Trobe University PhD student Angeline Leece in front of fossil bearing brecccia at Drimolen. (Jesse Martin)

A Dating Dilemma

The Drimolen Paleocave System is part of South Africa’s Unesco World Heritage Site called the Cradle of Humankind, a collection of limestone caves near Johannesburg that are one of Africa’s two great sources of hominid fossils. More than 900 have been found, representing at least 5 different species, during excavations that began nearly a century ago.

The big problem in South Africa has been dating all these finds. East Africa’s rift valleys, the continent’s other great hominin fossil source, feature layers of volcanic ash that can be dated by measuring the decay of radioactive elements, thereby dating the fossils within. In many South African caves, by contrast, older, fossil-filled sections have collapsed into lower areas. Modern humans operated mines in the area, too. The result is a confusing and complicated landscape that defies easy reconstruction.

Herries, who specializes in geochronology, says the Drimolen site is a bit different. It’s a small cavern that was deposited during a short period when water sunk into the cave, leaving a large sediment cone in the middle in which the fossils were found. Studies of the cave sediments show that this happened during a short window of time when Earth’s magnetic field flipped, a major help in dating the finds.

“That’s a huge advantage because we know when these magnetic changes occurred in the past,” Herries says. Scientists know when the field flips because the event leaves magnetic patterns in volcanic rock, especially in lava on the ocean floor, leaving a record of these reversals.

By using the known rate at which uranium decays into lead the team dated a tiny flowstone in the middle of the cave, formed by minerals in water that moved across the cave walls and floor, to about 1.95 million years ago—just in time for the magnetic field reversal. “That’s the critical combination that allowed us to date those layers, and date the bits where the crania come from which are slightly older than that.” The team also dated molars associated with the fossils using Electron Spin Resonance techniques with wider margins of error that nonetheless correlate to the same period. “My hope is that people will be convinced that we can date these cave sites in South Africa effectively now. It takes a lot of hard work, and a bit of luck.”

Potts was among those convinced by the dating but found himself even more impressed by the significance of the multi-species fossil find—something that until now was only seen in northern Kenya’s Turkana Basin, where four hominin lineages once coexisted.

“They’ve done a great job demonstrating that while there is this amazing diversity in East Africa (Turkana), there is an amazing but different combination of species diversity in South Africa, with different lineages of hominins hanging around at the same time. Now the number of such sites is doubled. That’s quite important in my view.”

Humans of the Kalahari Desert Region Formed Social Networks

Ostrich eggshell beads were exchanged between ancient hunter-gatherers living in distant, ecologically diverse regions of southern Africa, including deserts and high mountains. (Image courtesy of Brian A. Stewart, Yuchao Zhao, and the University of Michigan Museum of Anthropological Archaeology/John Klausmeyer) via Smithssonian.com

By Megan Gannon. First published at Smithsonianmag.com.

Foragers today who live in southern Africa's Kalahari Desert know that a drought or war can threaten their community's survival. To mitigate these risks, they enter into partnerships with kin in other territories, both near and far, so that if they have a bad year, they can head to another area to gather water and food.

"It's a really good adaptation to a desert environment like the Kalahari, which has huge spatial and temporal variability in resource distribution," says Brian Stewart, an archaeologist at the University of Michigan. "It can be very rainy in one season and in the next absolutely dry, or it can be very rainy in your area and then 10 kilometers away, it's just nothing." According to new archaeological research led by Stewart, this kind of partnership—which acts as a kind of insurance against one side of the partnership having a down year—has been happening for at least 30,000 years old.

In the study, which was published today in the journal Proceedings of the National Academy of Sciences, Stewart and his colleagues examined ostrich eggshell beads found during archaeological excavations at two high elevation rock-shelters in Lesotho, a country enclaved within South Africa. Since the 1970s and 1980s, archaeologists have been finding finished beads made from ostrich eggshells at prehistoric campsites in the area, Stewart says, even though ostriches are notably absent from the region. Based on this fact, and on anthropologists' comparisons with the systems used by modern hunter-gatherers, scientists assumed the ostrich beads to be part of the foragers’ long-distance insurance partnerships. That is, people from many miles away brought the beads and traded them to cement the social ties needed to ensure cooperation when one group of people endured tough times.

"Because of how effective this system is at shoring up risk, it's been used by a lot of archaeologists as a blanket explanation for why people exchange stuff," Stewart says. But, he adds, this idea hadn't really been tested for the archaeological record.

To figure out where the beads from Lesotho were created, Stewart and his colleagues examined their strontium isotope levels. Earth’s crust is abundant with a slightly radioactive isotope of rubidium that, over time, decays into strontium. As a result, different rock formations have different strontium signatures, and local animals can acquire those unique signatures via food and water. In this way, researchers can figure out where a 30,000-year-old ostrich came from.

"Now with globalization and our food moving all over the place—we can eat avocados in December in Boston, for instance—our strontium signatures are all messed up," Stewart says. "In the past, they would have been more pure to where we're actually from."

The study showed that the majority of the beads from the Lesotho rock shelters were carved from the eggshells of ostriches that lived at least 60 miles (100 km) away. A few even came from about 190 miles (300 km) away, including the oldest bead, which was about 33,000 years old. "The really surprising thing was just how far they were coming in from, and how long that long distance behavior was going on," Stewart says.

Archaeologists have documented, in the Kalahari and elsewhere, the deep history of long-distance movements of utilitarian items such as stone tools and ochre pigment, which can be used as a sunscreen or a way to preserve hides. In East Africa, researchers have recorded instances of obsidian tools being carried more than 100 miles (160 km) as early as 200,000 years ago.

"When you have stone or ochre, you don't really know that this exchange is representing social ties," says Polly Wiessner, the anthropologist who first documented the exchange partnerships among the Ju/’hoãnsi people in the Kalahari Desert in the 1970s. "However, these beads are symbolic. This is one of our only sources for such early times to understand social relations."

Wiessner suspects that the closer-range ties—the ones around 60 miles—that Stewart and his colleagues found indeed represent people who pooled risk and shared resources. However, she says, it’s possible that the few examples of beads that came from further away could have been acquired through trade networks.

"Often at the edge of risk-sharing systems, feeder routes extend to bring in goods from other areas by trade or barter and so the recipient does not know people at the source," says Wiessner, who wasn't involved in Stewart’s study but reviewed it for the journal. "It doesn't mean people had face-to-face contact from that far away."

Wiessner points out that people living 30,000 years ago were anatomically modern humans, so she would expect them to have large social networks. Similarly, Lyn Wadley, an archaeologist with the University of the Witwatersrand in South Africa, says, "I think that gift exchange is likely to have a much earlier origin." Wadley, who has studied the social organization of Stone Age hunter-gatherers but wasn't involved in the new study, also found the results convincing.

The new study suggests that the exchange network would have spanned at least eight bioregions, from arid scrubland to subtropical coastal forests. Stewart and his colleagues speculate that the system may have arisen during a period of climate instability, when access to a diversity of resources would have been crucial.

"This is just another piece in the puzzle of the incredible flexibility of our species," Stewart says. "We are able to innovate technologies that just make us so good at adapting very quickly to different environmental scenarios."

Who Were the Mysterious Neolithic People That Enabled the Rise of Ancient Egypt?

Neolithic skull. Author provided.

By Joel D. Irish, Professor and Subject Leader, Anthropology and Archaeology, Liverpool John Moores University; Czekaj- Zastawny Agnieszka, Associate Professor, Polish Academy of Sciences; and Jacek Kabacinski, Research fellow at the Institute of Archaeology, Polish Academy of Sciences. First published on The Conversation.

To many, ancient Egypt is synonymous with the pharaohs and pyramids of the Dynastic period starting about 3,100BC. Yet long before that, about 9,300-4,000BC, enigmatic Neolithic peoples flourished. Indeed, it was the lifestyles and cultural innovations of these peoples that provided the very foundation for the advanced civilisations to come.

But who were they? As it turns out, they haven’t actually been studied much, at least relative to their successors. But our excavations of six burial sites – with some of the analyses recently published – have now provided important insights into their mysterious ways of life.

One reason why we know so little about Neolithic Egypt is that the sites are often inaccessible, lying beneath the Nile’s former flood plain or in outlying deserts.

Excavation site. Author provided

With permission from Egypt’s Supreme Council of Antiquities (SCA) we – members of the Combined Prehistoric Expedition – explore Neolithic sites in Egypt’s western desert. The sites we are currently excavating lie along the former shores of an extinct seasonal lake near a place called Gebel Ramlah.

Though not lush, the Neolithic was wetter than today, which allowed these ancient herders to populate what is now the middle of nowhere. We focus on the Final Neolithic (4,600-4,000BC), which was built on the success of the Late Neolithic (5,500-4,650BC) with domesticated cattle and goats, wild plant processing and cattle burials. These people also made apparent megaliths, shrines and even calendar circles – which look a bit like a mini Stonehenge.

During the final part of the Neolithic period, people started burying the dead  in formal cemeteries. Skeletons provide critical information because they are from once living people who interacted with the cultural and physical environments. Health, relationships, diet and even psychological experiences can leave telltale signs on teeth and bone.

In 2001-2003 we excavated three cemeteries from this era – the first in the western desert – where we uncovered and studied 68 skeletons. The graves were full of artefacts, with ornamental pottery, sea shells, stone and ostrich eggshell jewellery. We also discovered carved mica (a silicate mineral) and animal remains, as well as elaborate cosmetic tools for women and stone weapons for men.

We learned that these people enjoyed low childhood mortality, tall stature and long life. Men averaged 170cm, while women were about 160cm. Most men and women lived beyond 40 years, with some into their 50s – a long time in those days.

Grave artefacts from 2001-2003 excavations. Author provided.

Strangely, in 2009-2016, we dug two more cemeteries that were very different. After analysing another 130 skeletons, we discovered that few artefacts accompanied them, and that they suffered from higher childhood mortality as well as shorter lives and stature. We’re talking several centimetres shorter and perhaps ten years younger for adults of both sexes.

Astonishingly, the largest of these two cemeteries had a separate burial area for children under three years of age, but mostly infants including late-term foetuses. Three women buried with infants were also found, so perhaps they died in childbirth. In fact, this is the world’s earliest known infant cemetery.

Interpreting the findings

So what can this tell us about these peoples, let alone their descendants? As it turns out, a lot. We can use the findings to make interpretationsabout gender, life-stage, well-being, status and other things.

For example, why were there such differences between the two grave sites? They could have been separate populations, but it is unlikely based on overall physical similarities. So perhaps they imply variation by status – with one graveyard being for the elite and the other for workers. This is the earliest such evidence in Egypt.

The sites also shed light on the family structures of the time. The overall sex ratio across all cemeteries is three women to each man, which may indicate polygamy. However, the total number of burials and a lack of reference to individual houses suggests these were extended family cemeteries.

We also believe that attainment of “personhood” – the age children are socialised into being “people” – was from three years, given their inclusion in adult cemeteries.

There is also clear evidence of respect for previously buried people by later mourners reusing the graves to bury their dead. When coming across old skeletons, they often carefully repositioned the bones of these ancestors. In some interesting cases, they even made attempts to “reconstruct” the skeletons by replacing teeth that had fallen out back into the skeleton – and not always correctly (see lead image).

These behavioural indicators, together with the seemingly innovative technological and ceremonial architecture mentioned earlier, such as the calendar circles and shrines, imply a level of sophistication well beyond that of simple herders. Taken together, the findings provide a glimpse of things yet to come in Ancient Egypt.

Conservation of sites

Well preserved vs. wind‐eroded remains at Gebel Ramlah. Author provided.

A key component of our work involves conservation of Egyptian (and world) heritage. We found no evidence of grave looting, unlike for sites in the Nile Valley. The last people to touch Neolithic material at Gebel Ramlah lived during that time. However, wind-related erosion has reached a point where once-buried remains lie on or near the surface.

In fact, the pace of destruction has increased significantly since 2001. Once exposed, the context of these sites can be lost and organic material can get sandblasted to bits. This means that if we hadn’t discovered these remains when we did, they would have soon been lost forever. But sadly this likely means that other sites from the time are literally disappearing.

For that reason, we and the SCA have decided that, when we have studied our material, all will be reburied on site to, hopefully, survive for thousands more years.

Related: Remains of 9,000-year-old Neolithic Settlement Unearthed Outside Jerusalem CNN

Africa's Past Revealed in Journeys of Ostrich Eggshell Beads

First published at The Conversation by Elizabeth Sawchuk Postdoctoral Fellow and Research Assistant Professor of Anthropology, Stony Brook University (The State University of New York) and Jennifer Midori Miller, Postdoctoral Researcher, Max Planck Institute for the Science of Human History.

You can tell a lot about a person by the things they wear, and this has likely been true throughout human history. The earliest kind of decoration was probably ochre, which we know humans have used for at least 200,000 years.

By 75,000 years ago, people begin wearing beads. Since that time, ornaments and other symbols have been central to the way we express our identities and signal our relationships. In fact, this is probably one of the things that makes us human.

Ornament production really took off about 50,000 years ago, when we see the earliest standardised jewellery in the form of small disc beads made from ostrich eggshells. In Africa, ostrich eggshell beads are one of the most common type of archaeological artifacts, particularly from sites dated to the last 10,000 years. They are also found in smaller numbers throughout Asia where 12,000-year-old ostrich eggshell beads have been discovered in China.

Since ostrich eggshell bead jewellery is still produced today, this is one of the longest running cultural traditions in the world.

Photo by Tom Podmore on Unsplash. Modern-Day ostrich strolling along cape point, cape peninsula, cape town, south africa.

But what can these beads tell us about the ancient peoples who made and wore them?

In a recently published paper, we analysed 1,200 ostrich eggshell beads from 22 sites in southern Africa and eight sites in eastern Africa. Although beads are found at many African archaeological sites, they tend to be overlooked in research. Many of the bead measurements for this study were taken from decades-old, unstudied collections and are being reported for the first time. We believe that this research demonstrates the importance of studying existing museum collections and approaching old questions in new ways.

Our aim was to see how ostrich eggshell bead size has changed over the past 10,000 years. Bead size has become an informal way to estimate the age of archaeological sites in southern Africa. Yet beads overall have received relatively little attention compared to other types of artefacts and there is much we still don’t know. Our study increases the number of published bead measurements from less than 100 to over 1000, allowing us to study patterns on a larger scale and gain new perspectives on the African past.

Our findings provide important insights into how ancient peoples responded to change. Topics like migration and the economy dominate today’s new cycle. Yet ancient peoples also faced issues like climate change, cultural contact, and economic shifts. The things that people made and used, like ostrich eggshell beads, can help us understand the impacts of these changes on their lives.

Photo by Team Mfina on Unsplash https://unsplash.com/photos/n_MZ5snB8qk

Herders versus hunter-gatherers

Three decades ago, the archaeologist Leon Jacobson noticed a pattern in ostrich eggshell beads from Namibia. Those associated with hunter-gatherer sites tended to be smaller than those associated with herder sites. Since we know that herding entered southern Africa around 2000 years ago, Jacobson suggested that sites with beads larger than about 7.5mm might be younger than that.

Other studies confirmed the same pattern within the western part of southern Africa. Some researchers also argued that bead size might help distinguish which sites were used by herders versus hunter-gatherers. But this remains contested.

Until now, the idea that ostrich eggshell beads changed with the introduction of herding had only been tested in the southern part of Africa, and with a limited number of sites. We therefore decided to test this with a much larger dataset, and in other places like eastern Africa where herding also spread some 3000 years earlier.

Regional variations

At the southern African sites, we also found that larger beads appeared after 2,000 years ago. However, contrary to previous studies, our data show that these larger beads did not replace long-standing bead traditions. In fact, the vast majority of ostrich eggshell beads continued to be quite small. On the other hand, beads from the eastern African sites were highly variable in size and showed no change when herding entered that region around 5,000 years ago.

Ostrich eggshell beads in eastern and southern Africa seem to tell a different story about herding’s spread. Cattle, sheep and goats are not native to either of these regions and must have been introduced by contact with peoples living farther north.

In both places, groups also made ostrich eggshell beads before and after herding spread.

In eastern Africa, the lack of change in bead size could suggest that local hunter-gatherers adopted livestock, or that incoming herders possessed similar traditions and/or quickly adopted local styles.

In southern Africa, the appearance of larger beads around 2000 years ago suggests the introduction of livestock stimulated a change in bead traditions, or that new styles were introduced at the same time as sheep.

Yet in both places, local bead traditions remained dominant. Curiously, the larger beads in southern Africa fall within the range of eastern African beads, hinting at contact between these regions as suggested by other archaeological evidence and ancient DNA.

Our research findings suggest that the spread of herding into new areas did not lead to the replacement of local peoples and practices. Rather, people responded in more nuanced ways and maintained certain cultural traditions.

This research not only helps us understand the African past, but is important for considering how we as humans use culture to cope with the changes in our world.

<

Lascaux 4, Full-Size Replica Of Ancient Cave Paintings, Opens In Dordogne, France

Often labeled the 'Sistine Chapel of prehistory', France's Lascaux cave paintings may be up to 20,000 years old. Included as a UNESCO world heritage site since 1979, the public has been banned from visiting the Lascaux caves since 1963. The caves were accidentally discovered by a group of boys in 1940, and for a period of time, visitors did tour the site. Archaeologists and art historians then discovered that the amount of carbon dioxide being exhaled by humans caused major damage to the integrity of the paintings, necessitating that they be closed from the general public forever. 

In a wonderful gift to the worldwide public, Lascaux 4, a full-size replica of the ancient cave paintings has opened in the Dordogne region of France. The whole Lascaux cave will be the essential part of Montignac-Lascaux Parietal Art international Centre, devoted to using the latest image technology and virtual mediation to recreate the experience of actually walking through the Lascaux caves. 

Nicolas St-Cyr, artistic decorator of Lascaux-4, officially known as the International Centre for Cave Paintings, is one of the few to have visited the real Lascaux. “It’s very special. You have the feeling you are in the presence of man 22,000 years ago when you see the paintings. These were talented artists, working by the light of animal oil lamps, and it’s like they were done yesterday. I was trembling when I came out.”

I made a fascinating discovery just now. Among the mysteries of the Lascaux caves is the reality that the paintings are almost all of animals. In Lascaux, there is only one man painted on the walls, amidst all the animals. In one of the most beautiful regions on earth, there are no paintings of flowers, trees or countryside. During this period (17,000-20,000 years ago) the predominant food was reindeer, and there are deer -- but no reindeer -- on the walls of Lascaux. 

Because AOC is fascinated with the history of mammoths and also long-buried mammoth ivory in Siberia, I had to ask Google: are there any woolly mammoths painted on the walls of Lascaux? The answer is 'no', but my question is a good one. The nearby Rouffignac cave, with drawings from a similar time period, is best known for the large number of woolly mammoths on the walls.