CULTURAL ROOTS A South African archaeologist digs into his own past to seek connections between change and development.

BY JEFF TOLLEFSON

etal scrapes on hard sand as archaeologist Chris Chris Henshilwood Henshilwood shaves away the top layer of sediment in inspects a on the . After just a few moments, the tip of his South African coast

M J. TOLLEFSON trowel unearths the humerus of a pint-sized tortoise that walked near Blombos. the Southern Cape of many millennia ago. Next come shells from local mussels and snails amid blackened soil and bits of charred wood, all remnants of an ancient feast. It was one of many enjoyed by a distinct group of early who visited Blombos Cave over the course of thousands of years. The Still Bay culture was one of the most advanced Middle groups in Africa when it emerged some 78,000 years ago in a startlingly early flourishing of the human mind. Henshilwood’s excavations at Blombos Cave have revealed distinctive , including carefully worked stone points that probably served as and tips, and bits of rock inscribed with apparently symbolic designs. But evidence of the disappears abruptly in sediment about 71,000 years old, along with all proof of human habitation in southern Africa. It would be 7,000 years

290 | NATURE | VOL 482 | 16 FEBRUARY 2012 © 2012 Macmillan Publishers Limited. All rights reserved NEWS before a new culture appeared, with a markedly 50,000 YEARS Howiesons different toolkit, including crescent-shaped AGO 4 CRUCIBLE OF CULTURE Poort culture blades probably used as . During the latest ice age, human populations ourishes in What drove the coming and going of these in southern Africa went through profound southern Africa. early cultures? At about the time the Still Bay changes that sometimes coincided with major environmental shifts. culture disappeared, the globe — already in the 5 Expansion of middle of a glacial period — began to cool even modern human ~200,000– 50,000 years ago populations in further, causing sea levels to fall (see ‘Crucible First appearance of anatomically Africa and onto of culture’). “Humans are very adaptable,” says modern humans in Africa. other continents. Cooler phase with lowered Henshilwood, “but I think climate must have sea levels. Exposed continental shelf provides played some role in the demise of the Still Bay.” new habitat for humans. 0 If there is a link, it may hold broader impli- 0 ,0

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p 0 e 0 during this period. Blombos r i o Cave, with its detailed archaeological record d of the , could become a key Cape Town East London testing ground. With Francesco d’Errico, an Port Elizabeth anthropologist at the French National Cen- Klipdrift tre for Scientific Research (CNRS) in Bor- Blombos S ta deaux, Henshilwood has assembled a team of rt o f Residents of Blombos 2 Still Bay culture archaeologists, climate modellers and palaeo­ m o Cave processed to inhabits Blombos Cave st climatologists for a five-year, €2.5-million r produce and store the and other sites in ec en . southern Africa. (US$3.3-million) project to look at correlations t ice Engraved ochre shows ag between climate and culture during the eventful e clearest evidence of span of that includes Still Bay, and the early symbolic thought. beginnings of modern human behaviour. “These are very daunting questions indeed, 00,000 but I think they are answerable,” says Henshil­ wood, a native of Cape Town who now works for a full excavation from the US National Sci- 72,000 years ago, his partner and co-excavator, at the University of Bergen in . “If we ence Foundation. In 2002, Henshilwood pub- Karen van Niekerk, sifts through the bottom can get some good climatic data, we can at least lished a study1 in Science documenting pieces strata of sediments, which are roughly 100,000 hazard some guesses.” of , iron-rich rock called ochre, which were years old. Centimetres away, the same layer engraved with cross-hatched patterns. He yielded Henshilwood’s most recent block- PERSONAL HISTORY argued that the 77,000-year-old etchings were buster find2: a toolkit of shells, grindstones and Outside the cave, a cool November breeze examples of symbolic behaviour and repre- crushing stones used to process and store ochre, scours the steep slope to the shore, which sented the earliest known evidence of abstract possibly for use as pigment or for utilitarian pur- Henshil­wood has known since he was a child. thought. These and other findings have chal- poses such as tanning hides or cleaning wounds. His grandfather bought this land on the lenged the once-dominant idea that human It was further evidence that Homo sapiens had Southern Cape as a fishing retreat in 1961 and culture — as exemplified by art such as carv- developed planning skills and sophistication far Henshil­wood spent his holidays searching the ings and — appeared in an explosive earlier than was once believed. hills and for ancient artefacts. transformation during the , Now a postdoctoral researcher at the Uni- Those experiences served him in 1985, some 40,000–50,000 years ago, in north Africa versity of Bergen, van Niekerk has been work- when, out of sheer boredom in his mid-thir- ties, he decided to leave the family department- store business and enrol in an archaeology DID CLIMATE WIPE OUT THE STILL BAY CULTURE? course at the University of Cape Town. In 1991, as a PhD student on a scholarship at the OR DID THE PEOPLE MOVE AWAY OR PERHAPS University of Cambridge, UK, he returned to Blombos in search of the same kind of artefacts JUST ADAPT OVER TIME? that he had found as a child. What he discov- ered was much more significant and far older: and Europe. Blombos and other sites suggest ing with Henshilwood since the early days at a series of bone tools and double-sided stone a more gradual cultural and technological Blombos. It’s a good life, she says, “and a lot points that were clearly tied to the enigmatic develop­ment, beginning far earlier, during the of work”. On this day she finishes early and Still Bay period. Middle Stone Age throughout Africa. heads to Henshilwood’s beach house and sci- “It was right over there,” he says, motion- On a visit to Blombos in November, the entific base to help a master’s student, Cornelia ing to the back of the cave. “Nobody cave looks like a war bunker, complete with a Albrektsen, to conduct an experiment using believed us, because nobody had found a generator, lights and sandbags. The team has -made stone and bone tools. They strug- Still Bay site for 40 years.” excavated just enough earth to create a work- gle for the better part of an hour trying to repli- The Middle Stone Age was not part of his space for a crew of five. Hundreds of steel tabs cate the way ancient people might have opened thesis, so Henshilwood covered the site up and mark strata on vertical walls of sediment. While shellfish. Then Henshilwood shows up. moved on. Only in 1997 did he secure funding Henshilwood works on the cave’s top layer, from “Give me one,” he says, grabbing a shell.

16 FEBRUARY 2012 | VOL 482 | NATURE | 291 © 2012 Macmillan Publishers Limited. All rights reserved NEWS FEATURE

Within minutes, Henshilwood pops open sev- beginning with the time spanning the Still Bay eral snails and determines which tools work and cultures. The last step is best. He then departs to clean up for dinner, to overlay the climate and cultural data onto an leaving the stunned crew to finish the experi- ecological model to analyse the environmental J. READER/SPL ment. “It was really impressive,” Albrektsen space occupied by specific cultures throughout says later. “He was getting all caveman-like.” time. The team can then look for links. Was one During a break in the excavations, Henshil­ , for example, always associated with wood stares out to sea and wonders aloud a particular environment? Do similar cultures whether the Indian Ocean holds answers. occupy similar landscapes or respond to climatic Palaeo­climate records from marine sediment shifts in similar ways? and ice cores suggest3 that around the time the “We can start to test our hypotheses about Still Bay culture disappeared, global tempera- the role of ecology and the environment,” says tures dropped and the polar ice sheets grew. William Banks, who runs the modelling at the Ocean levels fell, and the Still Bay people may CNRS in Bordeaux. have followed the sea onto the continental shelf, Henshilwood and his colleagues have some which would have become a productive plain. friendly competition. Curtis Marean, an archae- If this idea is accurate, most of the evidence ologist at Arizona State University in Tempe, would have been submerged as the ocean came to the cape shortly after Henshilwood, returned over the past 15,000 years. Henshil­ inspired by the genetic evidence of a popula- wood has hiked along more than 240 kilome- tion crash in the Middle Stone Age and thinking tres of coastline in search of caves that might that the cape would have been a good place for hold clues to the fate of the Still Bay. He hasn’t humans to ride out hard times. He partnered found any yet, but he is beginning excavations with Henshilwood on a paper4 examining bone on a site called Klipdrift Shelter, west of Blom- tools from Blombos in 2001 and went on to doc- bos, that could allow him to look at the rise ument the use of pigments5 and heat-treatment of Still Bay’s successor: the Howiesons Poort of stone tools6 164,000 years ago at Pinnacle culture, which appeared 65,000 years ago and Point, less than 100 kilometres east of Blombos. persisted for about 5,000 years. He is also looking to the sea for answers. Marean and a team of researchers have already Archaeological excavations at Blombos Cave have TIME AND TIDE produced an assessment3 of historical sea lev- yielded early evidence of abstract thought. Taking a break from Blombos, Henshilwood els around Pinnacle Point, and now they have visits the new site with Simon Armitage, a received money from the National Geographic Henshilwood acknowledges that compar- mineral-dating specialist at Royal Holloway Society in Washington DC and the US National ing environmental and cultural data may not University of London. Armitage uses a tech- Science Foundation to build a detailed geophys- yield concrete answers. The disappearance of nique called optically stimulated luminescence ical map of the continental shelf. Marean thinks the Still Bay, he says, could have resulted from to determine the last time a sample of dirt that the exposed shelf would have been a diverse climatic change, migration, the arrival of new saw sunlight before being buried. The shrubland ecosystem with edible roots, people or simply cultural evolution over the method requires Henshilwood big game for hunting and marine course of thousands of years. and others to cover Armitage resources. His goal is to recon- Back in the cave, Henshilwood settles down with a thick black tarpau- struct the vegetation, and into a familiar routine: digging carefully through lin and sit on its edge to then use models to analyse the sediments and thinking about the past. He prevent any light from how people might have uncovers the remains of a clam that lives along C. HENSHILWOOD fouling the measure- exploited those resources. sandy beaches and a mussel that prefers rocky ments. While waiting, “We need to develop shores, evidence that the Still Bay people had Henshilwood talks a thick empirical record access to a varied coastline much like the one about the significance and put that into a really he has been exploring all his life. Just behind of the site, which has tight timescale,” says Henshilwood is another hole, carefully filled already yielded a human Marean. “Once we have with sandbags. He dug that in 2007 as a test plot tooth and some artefacts that, we can start debating and found that the sediments inside Blombos with markings that could be the whys.” date back at least 130,000 years, with artefacts engravings. He says the find- Alison Brooks, director of dispersed throughout. “But that’s for another ings may turn out to be more Stone tools from Blombos Cave. the Center for the Advanced day,” he says, glancing at the wall of dirt in front fascinating than the decorated Study of Hominid Paleo­ of him. “Or another year, another decade.” ■ ochre pieces that made Blombos famous. biology at the George Washington University SEE BOOKS & ARTS P.304 Once the site has been dated, the research- in Washington DC, says that Henshilwood and ers will add it to environmental and cultural others are producing much-needed data and Jeff Tollefson covers energy and environment records from southern Africa and Europe. To hypotheses, but she warns against the dangers for Nature in New York. construct a climate record, Henshilwood’s team of oversimplification. Brooks is co-authoring a 1. Henshilwood, C. S. et al. Science 295, 1278–1280 is sampling cave deposits, in search of clues to forthcoming publication that aligns palaeocli- (2002). ancient rainfall and temperatures. They are mate data with archaeological data throughout 2. Henshilwood, C. S. et al. Science 334, 219–222 also testing ocean sediment cores for pollen Africa, and she says that (2011). 3. Fisher, E. C., Bar-Matthews, M., Jerardino, A. & and traces of charcoal that hint at vegetation, each region of the conti- NATURE.COM Marean, C. W. Quat. Sci. Rev. 29, 1382–1398 rainfall and the frequency of fires. nent seems to have has For more pictures (2010). The palaeoclimate data will allow a team at its own story. “There’s a from Blombos and 4. Henshilwood, C. S., D’errico, F., Marean, C. W., Milo, R. G. & Yates, R. J. Hum. Evol. 41, 631–678 (2001). the CNRS to build a high-resolution model lot of complexity here,” other sites, visit: 5. Marean, C. W. et al. Nature 449, 905–908 (2007). of climate in Europe and southern Africa, she says. go.nature.com/2kypzy 6. Brown, K. S. et al. Science 325, 859–862 (2009).

292 | NATURE | VOL 482 | 16 FEBRUARY 2012 © 2012 Macmillan Publishers Limited. All rights reserved