THE Official Magazine of the OCEANOGRAPHY SOCIETY

OceThe Officiala Maganzineog of the Oceanographyra Spocietyhy

CITATION Dybas, C.L. 2013. Ripple marks—The story behind the story.Oceanography 26(3):10–13, http:// dx.doi.org/10.5670/oceanog.2013.69.

DOI http://dx.doi.org/10.5670/oceanog.2013.69

USAGE Permission is granted to copy this article for use in teaching and research. Republication, systematic reproduction, or collective redistribution of any portion of this article by photocopy machine, reposting, or other means is permitted only with the approval of The Oceanography Society. Send all correspondence to: [email protected] or The Oceanography Society, PO Box 1931, Rockville, MD 20849-1931, USA.

downloaded from http://www.tos.org/oceanography Ripple Marks The Story Behind the Story by Cheryl Lyn Dybas

Ancient Eye on Humanity South Africa’s Blombos Cave Is a Window to Our Past—and Perhaps Our Future

It didn’t happen quite like this, but this “At home” is a perch high above the sea on a rocky ledge along the South African Will do for now: imagine how a clan coast east of Cape Town. “Just here” is an indentation on that cliff, a cave some Of folks—let’s say the first on earth—began 35 meters above sea level and 100 meters from the coast. One day to dream themselves beyond this place. Called Blombos Cave, it’s a time capsule sealed tens of thousands of years And some walked off and some did not, some came ago. The cave lies near Cape Agulhas, where the Atlantic and the Indian Oceans To coasts where some built boats and some did not flow into one another. The past and present—and perhaps the future— And some went pretty far away, to hot merge here as well. Or cold or different weathers. Some were changed. The cave’s opening, an almond-shaped eye, faces the sea. Once, it was shuttered by windblown sand from nearby dunes. But 20 years ago, archaeologist Christopher And some made bread and some made war, and all Henshilwood of the University of Witwatersrand, South Africa, and the University Forgot the place they had wandered from, of Bergen in Norway removed Blombos’ eye-patch. And made up names for what they had become What Henshilwood found would change our understanding of human his- And named their patch of earth and built their wall. tory—and the likely date when our species began to use symbols to communi- cate information. Now stand with me, just here. Let’s say we’ve come To know ourselves, and know ourselves at home. Room with a View—of the Distant Past Henshilwood first became interested in the cave in 1991. The archaeologist had —“Just Here, Blombos Cave,” Antony Dunn long searched the South African coastline for ancient artifacts. He hit pay dirt at Blombos, which, fittingly, lies on ground he owns. Empty shells of abalones, peri- winkles, mussels, and limpets were in the cave, the remains of edible shellfish.

(below) Blombos Cave entrance. Humans had been there…long, long ago. Photo credit: Magnus Haaland

10 Oceanography | Vol. 26, No. 3 Henshilwood’s grandfather bought the Dawn of the Modern Mind two- and three-inch-long engraved pieces of oceanfront property in 1961 as a fishing Homo sapiens was anatomically modern at rock, known as ochre, uncovered in the cave. retreat. He was among the most recent in a least 200,000 years ago. But when did we The ochre was scraped and ground to create long line of owners. The cave’s history goes begin to think as we do today? When did flat surfaces, then marked with cross-hatches back at least 140,000 years, when ancient humans open the earliest equivalent of a and lines to create complex geometric pat- humans fished and foraged for shellfish in Twitter account? terns. The pieces were found in deposits of the local waters, retreating within to fashion The cave may hold the answers. “The most ash and sand near hearths. “They were likely bead necklaces, mix bright red paint in shells, impressive single site for early evidence of fashioned with symbolic intent, the meaning make elaborate stone points used to spear symbolism is Blombos Cave, with a record of which is now unknown,” says Henshilwood. animals for food, and engrave reddish-brown stretching well beyond 70,000 years ago,” The next clue was in shells with holes in stones known as ochre. writes anthropologist Chris Stringer of the them, openings made, it would turn out, by When excavations at Blombos Cave began Natural History Museum in London in his human hands. in 1992, the entrance was obscured by dune 2012 book Lone Survivors: How We Came Diamonds are a girl’s best friend, or so the sand. Some 20 centimeters of undisturbed to Be the Only Humans on Earth. saying goes. The number of carats a diamond windblown sediments were draped across The Middle Stone Age began around or other precious gem contains is a status Later Stone Age deposits. The Later Stone 280,000 years ago and ended about symbol in today’s world. Our jewelry, our Age extends from about 50,000 years ago to 50,000 years ago. No one believed that the clothes, our cars. All advertise our resources, historical times. “When we entered the cave humans of that long-ago time had the ability and, perhaps, our social allegiances. for the first time, there had been no distur- to think in abstract patterns or to translate When did this human desire for adorn- bance of its contents after its last occupation that into symbols. ment begin? Was there a long-ago ancestor by humans,” says Henshilwood. It’s long been thought that symbolic behav- who found something shiny on the ground, Named for the white, bristly blombos ior originated in Europe. Scientists based that and started a fashion landslide? bush that covers clifftops along this stretch view on the culture of the cave-painting Ice Findings in Blombos Cave show that of coast, Blombos Cave has an interior area Age Europeans during the Upper Paleolithic, personal ornamentation started more than of about 55 square meters. Its long, low which started some 40,000 years ago. Sites 70,000 years ago. Researchers discovered entrance is 10 meters across, seven meters such as Chauvet Cave in the Ardeche region beads made of shells in sediment deposited deep and little more than a meter high. The of France, for example, showcase Ice Age during the Middle Stone Age. The shells are hollow gapes open in the shape of a cat’s eye. animals painted 35,000 years ago. among the earliest appearances of symbolic “If we use our imaginations, we can almost “When people are surprised at the objects in the archaeological record, and see the cave’s former inhabitants—our ances- stunning paintings of Chauvet,” says Jean mark an important step in the emergence of tors—at work,” muses Henshilwood, who Clottes, emeritus archaeologist at the French modern social behavior in early humans. first crawled into Blombos’ dark interior on Ministry of Culture, “I tell them about Henshilwood and others discovered hun- hands and knees. “They would be our envy, Blombos Cave. Modern humans—whether dreds of Nassarius kraussianus—“sea snail” or cooled by ocean breezes and with a beautiful in Europe or in Africa—had the same abili- tick shell—beads in Blombos Cave sediments view of the sea. Blombos Cave was ‘prime real ties tens and tens of thousands of years ago, dated to about 75,000 years ago. “The shells estate’ in the Middle and Later Stone Ages.” and Blombos offers proof.” had been transported a good distance from Indeed it does, believe Henshilwood and the environment in which they lived and had colleagues. Their first inkling came from clear evidence of human alteration,” he says. (below) Blombos Cave excavations in progress. Photo credit: Magnus Haaland Nassarius kraussianus dwells in estuaries, so the mollusks must have been carried to the cave from the nearest watercourses 20 kilo- meters down the coast.

(left) Map showing location of Blombos Cave at the tip of South Africa. Credit: Magnus Haaland

Oceanography | September 2013 11 The shells were strung together as neck- or of identifying oneself to members transferred to the abalone shells and gently laces or bracelets, had holes made by tools, of another group. stirred. A bone was likely used to turn the and marks around the openings like those in Not so different from another modified mixture and to transfer it out of the shell. items threaded on a string. “Wear patterns on natural object whose origins are in Africa: The recovery of the 100,000-year-old the shells imply that they were suspended,” the diamond. toolkits adds evidence for humans’ early says Henshilwood. “Some were covered in technological and behavioral developments: red ochre.” Ochre is a form of iron ore. Its red Shell Game: deliberate planning, production of pig- pigment was likely used as a decorative paint. One Shell Leads to Another mented compounds, and use of containers. Sand grains surrounding the artifacts were Blombos Cave’s tick shells, Henshilwood It also demonstrates, says Henshilwood, dated using a technique known as opti- would later discover, lay a few sediment layers that the people of the time had an elemen- cally stimulated luminescence. The results above other empty shells: those of abalones. tary knowledge of something we would show that the sediments were buried some These remnants of the marine world mark later call chemistry. 75,000 years ago. Thousands of individual what may be the most important Blombos grains of sand were dated to look for mixing Cave discovery to date: the abalones stored Ochre Paint Factories… between Middle and Later Stone Age layers. an ochre-rich paint mixture, possibly used for and Stone Tool Sharpening No blending was detected. decoration or skin protection. The date? One Workshops The finding indicates that shell beads in hundred thousand years ago. Shells, whether tick shells or abalones, and Africa became hot items at least 40 millennia “Ochre may have been applied with engraved ochres aren’t Blombos Cave’s only before the appearance of similar jewelry in symbolic intent as a decoration on bodies claims to fame. Europe. The shells infer that people alive and clothing during the Middle Stone Age,” A highly skilled way of sharpening and 75,000 years ago acted much like modern says Henshilwood. He and an international retouching stone artifacts was developed humans. “There have been questions about team of scientists discovered an ochre- there at least 75,000 years ago. Blombos Cave the links between anatomically modern processing workshop in Blombos Cave. Its inhabitants used a technique known as pres- humans and behaviorally modern humans,” toolkits included ochre, bone, charcoal, sure flaking. It involves taking implements says Henshilwood. “The people of Blombos grindstones and hammerstones. “The shaped by hard stone hammers, striking them Cave may have looked like us, but did they discovery is an important benchmark in the with wood or bone hammers, and finally behave that way?” evolution of complex mental processes,” says shaping the edges with a bone flaker. The engraved ochres and shell beads Henshilwood. “It shows that humans had The method is an accurate means of suggest they did. Use of items like beads to the conceptual ability to find, combine and controlling the sharpness, thickness, and signal information about the wearer requires store substances that may have been used to overall shape of bifacial—two-sided—tools skills unique to modern humans, including enhance social practices.” like spearheads and stone knives. Before well-developed language and an ability to The scientists, including Francesco d’Errico the Blombos Cave discovery, the earliest understand abstract concepts. Ornaments of the University of Bordeaux in France evidence of pressure flaking was from Upper made of modified natural objects, scientists and Karen van Niekerk of the University Paleolithic cultures in France and Spain some say, are the quintessential such items. of Bergen, believe that the manufacturing 20,000 years ago. “Once symbols were adopted by our ances- process involved rubbing pieces of ochre on Scientists—including Henshilwood, tors,” says Henshilwood, “communication slabs to produce a fine red powder. Ochre Paola Villa of the University of Colorado could rapidly develop. We were able to ‘trans- chips were crushed with hammerstones/ Museum of Natural History, and Vincent mit’ individual and group cultural values.” grinders made of silcrete (quartz grains Mourre of L’Institut national de recherches What the shell beads signified remains cemented by silica), then combined with unknown. The beads may have been a means heated crushed mammal-bone, charcoal, of conveying shared access to resources, stone chips and a liquid. The slurry was

12 Oceanography | Vol. 26, No. 3 CHERYL LYN DYBAS (cheryl.lyn.dybas@ archéologiques preventives in France— Where Have All the gmail.com), a contributing writer for Oceanography, is a marine ecologist and speculate that pressure flaking may have Cave-Dwellers Gone, policy analyst by training. She also writes been invented in Africa and used sporadically Long Time Passing? about science and the environment for there before its widespread adoption in After about 70,000 years ago, the Still Bay Natural History, Canadian Geographic, Europe, Australia, and North America. culture, to which Blombos Cave’s inhabitants Africa Geographic, BioScience, National The researchers analyzed 159 silcrete belonged, abruptly vanished. Where did these Wildlife, Scientific American, and many points and fragments, 179 other pieces, and technologically advanced early people go? other publications, and is a contributing more than 700 flakes from a layer in Blombos From conditions that were relatively editor for Natural History. Cave linked to the Still Bay industry, a Middle benign—warm and intermittently rainy—at Stone Age tool manufacturing style that about 76,000 years ago, say Henshilwood started roughly 76,000 years ago and may and Jessica Thompson of the University of have lasted until 72,000 years ago. Queensland in Australia, colder, perhaps expansion into Europe.” Blombos’ pressure flaking is important, the drier conditions and falling sea levels would To find out, Henshilwood, d’Errico, and archaeologists believe, as it shows that mod- have affected the hunter-gatherer-fishers of other scientists are midway into a project ern humans in South Africa had a sophisti- Blombos Cave. called TRACSYMBOLS, slated to run from cated repertoire of tool-making techniques Did climate change force our Homo sapiens 2010 to 2015. Its aim is to test the hypothesis at a very early time. It is a clear example, they ancestors to look for better hunting and that many of the cultural developments of say, of an ability to develop new ideas and fishing grounds? early Homo sapiens are related to climate techniques widely viewed as advanced, or Was the sophistication of these Middle variability. The scientists are reconstructing modern, behavior. Stone Age people the spark for a great climate, vegetation, and natural fire-related What would be next for the long-ago migration out of Africa, one in which changes in Europe and in southern Africa, residents of Blombos Cave, with their Homo sapiens acquired a position of world and comparing the ecological niches sophisticated spear points, containers, dominance among the competitors of the exploited by human populations during the and ornaments? time—Neanderthals in Europe and Asia, relevant climate phases. scattered populations of Homo erectus in the “Discovering the role of climate in shaping Far East, and tiny people, Homo floresiensis, the cognitive evolution of Homo sapiens is a on the Indonesian island of Flores? priority,” says Henshilwood. “It seems likely that the advanced technol- ogies and social structures of Homo sapiens Past is Prologue? that evolved in Africa,” says Henshilwood, If climate turns out to be a major factor, state “played a key part in the success of our Henshilwood and d’Errico in their 2012 book Homo Symbolicus: The dawn of language, imagination and spirituality, it “will serve to remind us that cultural innovations are not (above) Abalone after removal inscribed in our genes—climate change does of cobble with ochre. Photo not only affect what we can or cannot do, credit: Grethe Moell Pedersen but it also specifically defines who we were (right) Christopher Henshilwood and what we have become.” excavating in Blombos Cave. On a planet that is growing hotter and Photo credit: Magnus Haaland hotter, Homo sapiens is again at a crossroads. Will we continue to adapt and flourish as our ancestors ultimately did…or, like the Still Bay society, disappear into the sands of time?

(background photo) Blombos Cave. Photo credit: Magnus Haaland

Oceanography | September 2013 13