Aht#wHotl5 MUSEUM OF NATURAL HISTORY PUBLICATION FOR EDUCATORS ® VOLUME 31 NO. 1 SPRING 2010 WHAT DOES IT MEAN TO BE HUMAN? A BEHAVIORAL PERSPECTIVE by Alison S. Brooks MAR 1 9 Z013 "...// would be impossible tofix on anypointwhen the term "man" ought to be used " (Darwin 1 871 : 230) Anew permanent exhibit at the Smithsonian's Na- tional Museum ofNatural History asks the ques- tion "What does it mean to be human?" Before there were any fossils to inform us about the roads taken and not taken on our evolutionary journey, 18 th and 19 th century scholars wresded with the anatomical similarities between humans and apes, especially, as Darwin noted, the African apes. Many of the human distinctions these early scholars cited were behavioral, including language, tool-making and technology-dependence, culture, use of fixe, a sense of shame, burial of the dead, and a sense of the sacred. Even today, our anatomy alone may not suf- fice to define our genus Homo. Indeed in 1 964 one of the oldest members of our genus, Homo babilis, was defined as Homo to a large extent on the basis of the tools found in association with its bones; the evolutionary or generic status of the bones themselves remains controversial. As in the museum's new exhibit, new approaches to under- standing our past and defining our species emphasize the role of changing human behavior and its relationship to and possible role in changing our anatomy. This paper offers a brief summary of key discover- ies in the fossil record followed by a discussion of be- havioral characteristics defining modern humans and their emergence through time. This is followed by a descrip- tion of the evidence documenting the development of archaic, Neanderthal, and modern humans, tracing the evolution ofkey behaviors from 600 kya to 40 kya (thou- sands of years ago). Finally, the evidence for the role of Africa in the gradual evolution of distincdy modern hu- man behaviors is argued as the paper concludes. The Fossil Record of Human Evolution Charles Darwin in his 1871 book, The Descent ofMan, located the likely origination ofhumans in Africa due to the geographic distribution and comparable anatomy of the chimpanzee and gorilla. Other early scholars, how- ever, thought that our two most distinctive anatomical features, our large brains and our two-legged gait, had evolved together and that these changes had happened in Europe. In Darwin's time, only a few fossils of Nean- t 4 Smithsonian * National Museum ofNatural History VnthroNotes Volume 31 No.l Spring 2010 derthals, our closest extinct relatives, had been recoveredfrom European sites. The 1 891 finding inJava of Pithecan-thropus erectus (now Homo erectus), an upright biped with acranial capacity of only 900cc, argued that both of theseideas were false; bipedalism came first and not in Europe.Only much later in 1924 were the first African fossils ofhuman ancestors recovered at Singa (Sudan) and Taung(South Africa). The ca. 2-2.5 million-year-old Taung speci-men of a small child with a chimpanzee-sized brain be-came the type fossil ofAustralopithecus (Dart 1925), a genusthat is probably ancestral to our own {Homo). Like the Pith-ecanthropus discovery, the Taung child's human-like teeth,small brain but upright posture, as indicated by the posi-tion of the skull on top of the spine, suggested that braindevelopment lagged behind new ways of getting around.Most scholars in the 1 920s, and some much more re-cently, continued to argue that major changes in the humanevolutionary past occurred in Eurasia. But since the 1920s,Pliocene and Pleistocene age (5.3 — 0.01 million years agoor mya) fossil specimens belonging in the hominin lin-eage—representing more than 6,000 individuals—havebeen recovered at an accelerating pace from Europe, Asia,Africa, and Australia. Africa has yielded the oldest mem-bers of the human lineage ("hominins"), the oldest stonetools, the oldest members of our genus Homo, and theoldest members of our species Homo sapiens. Multiple ge-netic studies of modern human mitochondrial Y-chromo-some and nuclear DNA conclude that the greatest vari- ability, the most ancestral lineages, and the likely region oforigin are all African, proving that Darwin was right inassigning us an African origin.The emergence of a richer fossil record raises anewthe question, what do we mean by human? Are the earliesthominin fossils from 7-3 mya whose skeletons reflect somelevel of bipedal locomotion human? (See accompanying article on the development of bipedalism.) Does the ge-nus Homo begin with the appearance of stone tools 2.6mya, or with the first reduction in molar size around 2.3mya, or with the first signs of brain enlargement in Ethio-pian and Kenyan fossils from 1.9 mya? Should we onlybestow the word "human" (or the generic/evolutionarystatus of Homo) on fossils with the human-like suite ofcharacteristics reflected in the relatively complete skeletonof the 1 .5 mya "Turkana Boy." Found in northern Kenya,this fossil had a brain almost 2/3 the size of ours, smaller teeth than in previous hominins, and modern body sizeand limb proportions reflecting fully-committed bipedalwalking and running. Should we limit the definition of "fullyhuman" only to members of the species Homo sapiens, de-fined morphologically by large brains in relation to body size, small teeth, gracile skeletons, chins, minimal browridges, vertical foreheads, and faces tucked under brain-cases in such a way as to facilitate speech? Or perhaps onlyto those members of our species who demonstrated ad-vanced abilities for symbolic behavior, innovation, and socialcomplexity?A Behavioral PerspectiveLike the expanding fossil record, studies of great apes inthe wild have documented many human-like behaviors,blurring humans' behavioral distinctiveness. All the greatapes make and use simple tools, and their tool use andother behaviors vary among populations, suggesting thatgroups invent and hand down different behaviors fromone generation to the next, a rudimentary form of 'cul-ture.' While spoken language is still a major defining featureof humans, many humans use other forms of communi-cation, and some apes have proven capable of learningfrom humans or even from each other to communicateusing elements of sign language. Psychologists focus onthe expression, in humans, of such characters as "empa-thy" and "problem-solving abilities." However, in almostevery case, at least one of the great apes (or some otheranimal) has shown this feature in some form. An absolutedistinction between humans and non-human animals hasthus far proved elusive.What can the fossil and archaeological records tell usabout the evolution ofhuman behavior? Even before thereare any tools or archaeological sites, the fossils themselvesreflect behavior in the shape of bones, the position andstrength of muscle markings, the form of the teeth, thepatterning of reinforcing structure inside the bone and itschemical composition, as well as in signs oftrauma over alifetime. The long arms, curved fingers and toes, and up-wardly-oriented shoulder joint ofAustralopithecus reflect alife still lived partially in the trees. Small canines suggest anew, less confrontational approach to male-male relation-ships and social organization, whilechemical studies oftheteeth suggest that later ones may have begun to exploit thesame foods that make up large parts of the human diet —meat and tubers. The reconstructed environments of the Page 2 AnthroNotes Volume 31 No. 1 Spring 2010 sites themselves also tell a story—of early use by homininsof a wide range of environments both in and out of theforest.Between 2.6 and 2.3 million years ago in Ethiopia andKenya, along with Australopithecus and some fossils withslightly smaller teeth and shorter faces attributed on thatbasis to Homo, we begin to find material remains in theform of flaked stone tools and bones that were cut andbroken open to access meat and marrow. Such archaeo-logical sites are formed through human activities, althoughit has been shown that chimpan2ees also leave archaeologi-cal traces of their behavior.The fossil and archaeological records are limited in whatthey can say about the origins of humans, as they requiredefinitions ofhumanness that are amenable to recovery inthe material record. For example, one cannot recover fos- sil languages, at least not until the development of writing.But one can recover traces of symbolic behavior, or mor-phological traces of changes in brain or vocal tract mor-phology that suggest an ability for language. Ideologies orthe capacity for abstract thought are not preserved, butone can recover traces of practices that seem to conformto ideas about spirituality—burial of the dead and cave art.Problem solving and creative innovation cannot be directlyobserved in the past, but one can document increases intechnological sophistication and rates ofinnovation. Socialnetworks and societies in which humans live are abstrac-tions that must be inferred from physical evidence even inliving populations. But through geochemical analysis ofwhere raw materials came from, one can trace the move-ment of materials like stone and beads over very long dis-tances and thereby infer human networks' size and distance.In addition, from patterns ofvariability in the materialrecord, it is possible to infer whether or not people distin-guished themselves from their neighbors through theirmaterial culture, and what the size ofthe distinctive group-ings might have been. Signs of empathy may also be evi-dent in the survival of individuals with crippling injuries ormajor deficits, who could not have survived long on theirown.Defining Human BehaviorFrom the perspective ofmodern humans, behavioral defi-nitions ofhumanness include what can be considered "liv-ing in our heads," enabling us to transform the natural world. Multipurpose tools, such as hand axes, used to chopwood, butcher animals, and make other tools , dominatedearly human technology for more than a million years. Leftto right: Africa (1.6 million years old), Asia (1.1 millionyears old), and Europe (250,000 years old). Photo courtesyHuman Origins Program.Humans think up cultural solutions to scarcity, risk, and thequest for food, shelter and mates, resulting in an astound-ing diversity of cultural forms and the transformation ofvast areas of the earth's surface. Since humans' teeth andtheir two-legged gait are utterly inadequate for defenseagainst natural predators, humans are totally dependent oninvented technologies. Rather than living in a physical herdor a pack, humans live in what have been called "imaginedcommunities," populated by individuals never physicallyencountered—distant relatives, compatriots, ancestors, and spiritual beings. Humans use symbols extensively to repre-sent themselves, their social groups, and their thoughts. Hu-mans have the ability to imagine the feelings and lives ofothers as both separate from and similar to their own—ina way that leads to extraordinary capacities for altruismand sympathy, even for individuals they may never meet.One way to describe the capabilities of modern hu-mans is to separate out at least six different faculties:Abstract thinking, the ability to act with reference toconcepts not limited in time and space. A chimpanzee canbe taught to use symbols correctly to solicit a reward, butnot to go to the grocery store with a shopping list andremember that she forgot to write down the bananas. Page 3 [nthroNotes Volume 31 No.l Spring 2010 Planning depth: the ability to strategize in a group con-text. Social carnivores share this ability in the immediatefuture, but lack our ability to plan for next year, or forcontingencies that may never happen.Problem-solving through behavioral, economic, and technologi- cal innovation: Many animals are good problem solvers, butmodern humans solve problems that have not yet arisenand devise entirely new ways of living in the process.Imagined communities: Our present communities, fromfamily to nation, may include people we have never met, spirits, animals, and people who have died and the not-yet-born. These communities exist in our heads and never meetface-to-face as a group.Symbolic thinking: Especially with regard to informa-tion storage, this involves the ability to reference both physi-cal objects/beings and ideas with arbitrary symbols, and toact on the symbol even if the person who planted it is nolonger present. It is both the arbitrariness of such symbolsand their freedom from time and space constraints thatdistinguish our symbolic behavior from that of animalsand constitute the foundations ofhuman language.Theory of mind: The ability to recognize oneself as aseparate intelligence but at the same time to read the emo-tions and thoughts of others (empathy). Apes and evendomestic carnivores possess this to a degree, but onlymodern humans can respond to humanity in individualsthey will never meet.The Early Record: 2.6 - 0.6 mya If all these are key human abilities, when did they first ap-pear? It is difficult to say, not only because the record issparse and patchy, but because the capability may or maynot be expressed for hundreds or thousands of years afterit appears and may depend on the development of otherfactors or historical events. The capability for inventing com-puters may have existed in the late Pleistocene, but couldnot be expressed without the appropriate cultural and tech-nological milieu. The limited evidence for these character-istics' early expression suggests, however, that the total pack-age was not assembled over a short period. Problem-solving and technologicalinnovation. The first stonetools date to 2.6 mya from Ethiopia, slightly later in Kenya.There is little evidence for abstract thinking in these arti-facts as they consist of simple flakes directly related to theform of the raw material, although the ability to chooseappropriate raw materials and to derive multiple flakes from a single block is far beyond what even the smartest apescan be taught to do. The rate of change or innovation isinitially very slow; new forms such as bifacially workedsymmetrical handaxes appear only after the first 900,000years; and tools remain static for more than 1 mya afterthat. Nevertheless, such tools made it possible for earlyhumans to shift from the largely frugivorous diet of thegreat apes to a diet with substantial carnivory and exploita-tion of new foods such as underground tubers. By 1.9-1.6mya, our early ancestors also could expand into the NearEast, Indonesia, and China, far beyond their original rangeand adapt to the new environments and faunas there. Tech-nology also seems to have made possible a shift in foodpreparation from teeth to tools, so that teeth became smallerwhile body size increased. Early human diets were prob-ably omnivorous, with meat obtained largely by scaveng-ing. Fire was controlled by 0.8 mya or earlier, facilitating anew diet, the use of caves, hunting, new technologies, andsocial time at night.There is no evidence from this time for imaginedcommu- nities or symbolic thinking. Stone and other materials appearto have largely derived from within about 15 miles (25km) of the site. Technologies are very similar from Indiato England and from France to South Africa.Empathy, which appears very early in modern childrenbefore competent speech, may already be reflected in avery early human skull from Dmanisi in the Caucasus at1 .9 mya. The individual had lost almost all his teeth a consid-erable time before death, a condition rarely found in wildprimates. Survival of this toothless individual required ei-ther a new, very soft diet or the assistance of others.The early appearance of these features does not meanthey were as fully expressed as in modern humans or eventhat the full capacity existed as in ourselves. But it doesindicate that the human capacities do not arise suddenly infull-blown form but rather develop over time from lesshuman antecedents.Late Archaic Humans and Neanderthals:600 kya to 40 kyaBeginning before 600 kya (thousands of years ago), mostfossils in Africa, Europe, and the Near East present essen-tially modern brain sizes, although their teeth and faces are still large. In Africa, this shift may coincide with a new stonetechnology (Levallois), requiring a greater degree of ab- Page 4 AnthroNotes Volume 31 No. 1 Spring 2010 stract thought to imagine the flakes whose shapes werepredetermined by the shaping of the cores. Evidence ofan increase in technological innovation, larger social net-works or symbolic behavior, however, is minimal until ca.400 leva, although new evidence ofan occupation of south-ern England ca. 700 kya years ago suggests the ability tomeet the challenges of a much more temperate environ-ment. Ocher's increased use in Africa by 240 kya or earliermay suggest body painting or alternatively a more utilitar-ian function. Wooden spears or javelins from Germanyand numerous remains of large animals imply a more com-plex hunting technology, which may have facilitated theoccupation of much higher temperate latitudes.Neanderthals, who occupied Eurasia as far east asUzbekistan between ca. 250 and ca. 35 kya (or even later ina few 'refuge' areas) were significantly more like modernhumans in their behavior than their predecessors. Theyburied their dead, but without clear evidence of gravegoods or associated symbols, used black and red mineralpigments found as powder, lumps and "crayons," madestone-tipped spears, and were competent hunters of largegame. Their fossil remains bear traces of both interper-sonal aggression, in the form of a knife wound, and em-pathy, as elderly and handicapped individuals survived formuch longer periods than previously. Although Neander-thals occupied Europe for at least 200 kya, their technol-ogy shows very little innovation or regional differentiationuntil the last 15 to 20,000 years of this time. The Neander-thal brain was similar in size to ours when adjusted fortheir larger body mass, but the relationship of the tongueand soft palate to the laryngeal space suggest that they may still not have been capable of all the complex speech soundsmade by modern humans. Personal ornaments are onlyfound at the most recent Neanderthal sites, after 50 kya,dating to a time when anatomically modern humans werealready on the periphery of Europe. Does this mean theNeanderthals possessed a capacity for innovation and sym-bolic behavior, or only a facility for imitation?Modern Humans, Homo sapiens:An African OriginInto the 1 970s itwas thought that modern humans evolvedin Europe. But with the advent of new fossils and betterdating techniques, it has become clear that the oldest ana-tomically 'Homo sapiens'fossils were African. The oldest fossil These 30,000-year-old shells from Cro-Magnon, France,represent some of the earliest evidence of humans wearingjewelry. Some shells have traces of ocher, a clue they werecolored with pigment. Photo courtesy Human OriginsProgram. attributed to Homo sapiens in Africa is more than five timesas old as the oldest Homo sapiens in Europe. At the sametime, genetic studies demonstrate that all living humans sharea 'recent' African common ancestor who lived between100 and 200 kya. One group of African genetic lineagesshares a common ancestor with all non-Africans that isconsiderably younger, perhaps 40-80,000 years ago. Al-though at first these results were disputed, repeated geneticanalyses have confirmed our African origin. DNA sequenceshave been recovered from Neanderthals who lived as farapart as Spain and Siberia. The resulting sequences sharesimilarities with one another but indicate at least three re-gional populations and contain many sequences not sharedwith living humans, suggesting at least 400 kya of separateevolution.The rapid appearance of modern-looking people inEurope was not a punctuated "human revolution" or "greatleap forward." It was an invasion of people with longtropical limb proportions. Asia has a more complicatedbut equally punctuated history, also suggesting invasion andultimate dominance by outsiders. Indeed the first "out-of-Africa" migrations ofHomo sapiensv/ere, to the Near East,with modern humans appearing first at Skhul and Qafzehin Israel between ca. 110 and 90 kya, an initial wave thatdoes not appear to have spread beyond this region until50-60 kya. Modern humans then disappear from the Le-vant, as Levantine fossils from 90-50 kya are all Neander-thals. Modern humans expand again at or before ca. 50kya. Page 5 InthroNotes Volume 31 No.l Spring 2010 II '*«l» 1 i "Rapid appearance of modern-looking people in Europe wasnot a great leap forward." Modern Humans: Revolution or GradualEvolution?The earliest Homo sapiens in Europe and Asia, ca. 40kya and later, were almost certainly capable of the samerange of behaviors as we are, as indicated by their cavepaintings, sculptures, musical instruments, beads and otherjewelry, trade networks, technological innovations, regionaldiversity, economic flexibility, and ability to colonize theentire globe. There is considerable debate about earlierhumans in Africa who were physically similar to us in manyways. Some scholars argue that they were physically mod-ern but behaviorally primitive. To these scholars, modernbehavior came about suddenly, a "Human Revolution" tiedto a rapidly spreading genetic mutation for language.In a 2000 paper, Sally McBrearty and I argued other-wise, that the capabilities for these behaviors began to beexpressed and therefore existed even before modern physicalappearance, with a gradual assembly of the kinds of be-haviors we see later. This assembly was not unilineal butgeographically and temporally sport}7, with many reversals.Archaeologists look especially for technological in-novation and complexity as proxies for problem solving;for long-distance exchange and economic intensification asproxies for both planning depth and imagined communi- ties; for regional styles that change over time as proxies forsymbolic thinking and/or imagined communities; and forbeads, images, and notational pieces along with burial ofthe dead as proxies for abstract and symbolic thinking andtheory of mind. For all of these material expressions ofbehavioral capabilities, there are modern, even living groupswithout them. While demonstrably capable of producingsuch items, these groups clearly lack the impetus or thehistory to do so, so absence may not be a good marker ofnon-modernity. But absence of all of these over long ar-chaeological stretches of time cannot be characterized as "modern behavior."Since 2000, the rapidly accumulating record of hu-man behavioral evolution in Africa has confirmed, ratherthan contradicted, our basic model ofan earlier and moregradual accumulation of complex behaviors expressed inmaterial culture. Beads, decorated ocher and ostrich egg- shell, innovative technologies involving hafted projectiles,and even the possibility of complex projectile weaponssystems, have all been argued for Middle Stone Age (MSA)peoples predating 60 kya. Furthermore, new dating andstudy of previously excavated materials have shown thatburials of H. sapiens with grave goods are found both inSouth Africa and in the Near East, dating to 66-90 kya and90-100 kya, respectively. These burials suggest that sym-bolic behavior characterized at least some of the earlymembers of our species long before the main "Out ofAfrica" event suggested by genetic dating.But after more than a million years with little change intechnology, the African record suggests that well beforethe first appearance ofHomo sapiens, even before 285 kya,behavior had begun to change. New technologies producedstandardized stone flakes and long thin blades, ocher pro-cessing increased, and many sites have small quantities — up to 5%—of stone material derived from sources a con-siderable distance away, as much as 125 miles (200 or morekm)— the first sign of an expanded social network. Thebehavioral changes reflected in these finds are not suddenor directional. The evidence for them is interspersed with sites containing the old symmetrical large cutting tools, orsimple flake technologies, or lacking evidence for ocher orexotic stone. But the general trend is towards more com-plex behaviors with time. Importantly, by ca. 267 kya, sev-eral sites in South and East Africa include carefully madestone points, designed for hafting onto spear shafts. Page 6 AnthroNotes Volume 31 No. 1 Spring 2010 New TechnologiesMore dramatic changes in behavior occur after the ap-pearance of Homo sapiens. From South Africa to Egyptand from the western Sahara to Ethiopia, evidence forcomplex technologies and new tools increases especiallyafter 100 kya. In Ethiopia, the first Homo sapiens at about195 kya are associated with advanced flake technologiesbut the older symmetrical large cutting tools continue atsome sites in the Horn of Africa. Before 90 kya, stonepoints are large or thick, and were likely hafted onto thrust-ing spears used in close encounters with prey. But after 90kya, the points become tiny and light. Possibly these verysmall later points, which could not have delivered a lethalblow to a large animal, were hafted on the ends of spearthrower darts or arrows, and even associated with the useof poison.As earlv as 130 kya, another set of technological inno-vations appears to have focused on fishing. In the easternDemocratic Republic of Congo (Zaire) our team discov-ered a series of what appeared to be Middle Stone Agelocalities along the river. Excavations at three sites revealedmammalian fauna and lithic artifacts but also a series ofbarbed bone points associated with thousands of fishbones. The dates for these sites have varied, but lumines-cence dating suggests an age of 80-90 kya, and there is noevidence for an age less than 60 kya. Again, this is a com-plex technology that appears to have been outside Nean-derthal competency.Small projectile armatures in a complex weapons sys-tem could have given the edge to later modern humans,allowing populations to expand both within and outsideAfrica at the expense of the Neanderthals and other ar-chaic populations. Neanderthals had many injuries frompersonal encounters with large dangerous animals, but latermoderns had very few. Neanderthals also had many moresigns of dietary stress in their bones and teeth than the earlymoderns who succeeded them.Long-Distance ExchangeAt several sites in East and Central Africa, some stone toolsmade by early modern humans use stone that does notcome from the local area. Throughout East Africa there isa preference in many sites for obsidian, a fine black volca-nic glass with very specific chemical characteristics. In manyareas, such as the Aduma area in the Mddle Awash region of Ethiopia, obsidian sources do not occur in the immedi-ate vicinity of the sites, and the obsidians themselves arevaried and appear to derive from multiple sources. Whenthe chemistry of the obsidian can be matched to specificsources, as at Mumba in Tanzania, it suggests that obsidianwas being moved more than 125 miles (200 km) in somecases. This suggests the existence of trading networks, or "imagined communities." Distant trading networks wouldbenefit from the use of symbols to identify members ofsuch a community, so it is not surprising that ocher andother minerals were also processed for pigment at some sites such as Twin Rivers in Zambia, as early as 240 kya.Other indicators ofimagined communities are the regional "styles" of projectile points that possibly identify social entities in space.Symbolic BehaviorSo far, we have demonstrated the presence of technologi-cal innovation, economic intensification, long distance ex-change, and regional styles in the behavioral repertoire ofearly modern humans. But is there hard evidence for sym-bolic behavior? In 2002, an extraordinary piece ofengravedocher was described from Blombos cave in South Africa.It and a second similar piece clearly suggest that ocher hadmore than a utilitarian function. Many other pieces ofocher,bone, and eggshell with engraved geometric or linear de-signs are known both from this site and from other south-ern African sites, including fragments of decorated ostricheggshell containers from ca. 65 kya at the Atlantic coastal site of Diepkloof.Beads and other body ornaments are unequivocal evi-dence for symbolic behavior and for fully human status, asthey have little utilitarian function. In traditional huntingsocieties, beads provide the basis of exchange networksthat served to tie distant people together in a mutual sup-port network, particularly useful when times are bad. Indi-viduals deliberately build these networks up as they growinto middle age and acquire major responsibilities for rais-ing and marrying off children or for supporting elderlyparents. As they age and their needs decrease, individualsbegin to reduce the size of these networks.Beads and personal ornaments such as rings or head-pieces also serve as markers of social identity or statusworldwide. Examples include wedding bands, the color-ful collars of the Maasai, and diamond necklaces of soci- Page 7 inthroNotes Volume 31 No.l Spring 2010 ety women (or men). Despite extensive excavation, nobeads are known from Europe before ca. 50 kya. EarlyAfrican sites have yielded a few ostrich eggshell beads inearly sites—an unfinished one from South Africa(Boomplaas) dated to ca. 60-80 kya, and several from Tan-zania (Mumba) dated direcdy to between 45 and 52 kya.In 2004, a series of perforated shell beads from the coastof South Africa, dated to 76 kya, made headlines as theoldest evidence for personal ornaments. Even older shellbeads have been described from sites in North and EastAfrica, as well as in sites of early modern humans in theNear East.The evidence for human burial practices with graveofferings indicative of symbolic behavior within Africa islimited, due in part to the relative dominance of open airexcavations where bone preservation is poor, and in partto probable cultural practices of burial away from living sites. Two relatively elaborate cave burials at early dates,however, confirm the antiquity of this practice among mod-ern humans at opposite ends of their early geographicrange: an elaborate modern human burial at Qafzeh inIsrael dated to 100-130 kya, a time when both modernhumans and African faunas expanded into the Levant andthe burial of a child at Border Cave in South Africa datedto 66-90 kya. The child burial is associated with what ap-pears to be ocher and has a large perforated Conns shell inits chest area. The nearest source for the shell is the IndianOcean ca. 50 miles or 80 km away. The Qafzeh individualwas associated with 71 pieces of red ocher, and also witha perforated bivalve shell. These two sites constitute theearliest clear evidence for symbolic burial with grave goodsand red ocher, practices that suggest a belief in the survivalof a spirit after death.Emergence of Humanness: A Gradual ProcessThe accelerating rate of technological innovation was astepwise process, not a sudden event related to language.By 70 to 60 kya, well before the out-of-Africa event thatled to Neanderthal extinction, anatomically modern hu-mans in Africa, and occasionally in the Levant, had lightcomplex projectile weaponry, fishing and bone fishingspears, long distance exchange networks, ocher, deliberateburial with grave goods, regionally distinctive point styles,symbolic engravings and personal ornaments. Within Af- rica, there was probably a complex web of inter-regionalmigration and local extinction that makes the record patchy and discontinuous. In addition, demographic and climaticfactors may affect the degree to which any of these mod-ern human capabilities are expressed. Ethnographic stud-ies suggest, for example, that symbolic expression, subsis-tence practices, and regional networks intensify under con-dition of resource stress.Neanderthals, on the other hand, before 50 kya, hadhafted spear points, used a large amount of black coloringmaterials, and practiced simple burials without offeringsor ocher. There is little evidence in this early time range forNeanderthal fishing and none for bone tools, musical in-struments, cave art, or personal ornaments. After 40-50kya, when modern humans were already on the Neander-thals' periphery or perhaps in their midst, Neanderthalsdeveloped or adopted some of the same traits—particu-larly the beads and stone technologies. But they still lackedsmall light projectile armatures (points) and rarely if everwent fishing. And the really long distance raw materials areonly marginally present towards the end of their existenceat the northeast edge of their range in Eastern Europe andCentral Asia. In both regions we would expect human ter- ritories to be very large and populations sparse.Why was Howo sapiens able to replace Neanderthals inEurasia after 50 kya but not before? There seem to bethree possibilities: 1) a sudden genetic mutation, 2) techno-logical superiority, or 3) more sophisticated social networks.These networks, supported by a greater use of symbols oreven language, would have buffered humans against risks.A fourth hypothesis is that invading Africans brought withthem epidemic diseases to which the Neanderthals had no resistance.In any event, Neanderthals survived long enough toleave archaeological and/or fossil traces in several sites insouthern Europe that are contemporary with sites of earlymodern humans in Europe over a period of at least 6000-7000 years. Co-existence in the Near East may have oc-curred over an even longer period. New work on the nuclearDNA genome of Neanderthals even suggests that mod-ern populations in Eurasia (but not in Africa) carry a smallpercentage (1-4%) of Neanderthal genes, implying thatNeanderthals and modern humans interbred in the NearEast, before modern humans expanded to the rest ofEurasia. (This and other new genetic studies bearing onhuman evolution and migration will be covered in a futureAnthroNotes article) . Page 8 AnthroNotes Volume 31 No. 1 Spring 2010 ^"hile the answer to the question ofwhy Homo sapienswas able to replace Neanderthals is almost certainly morecomplicated than any of these three simple hypotheses of-fered above, and may involve combinations of them andothers, the evidence against a revolutionary genetic event isstrongwhen you consider Africa. That continent is charac-terized by the earlier appearance oftechnological and eco-nomic complexity, as well as of complex symbolic behav-ior. The patterning of change both during and at the endof the Middle Stone Age period of early Homo sapiens isalso very different from that consistent with a genetic revo-lution, as it is both spotty and gradual. Such gradual pat-terning is much better explained in earlier anatomicallymodern humans bv assuming the existence in earlier ana-tomically modern humans ofmodern behavioral capabili-ties that are variably expressed when conditions call forthem. NXTien either climate change or population growthcreated effective crowding, in an otherwise sparsely inhab-ited landscape, such pre-adaptation could have becomeexpressed in modern behavioral capabilities.ConclusionCurrently available data suggest that our ancestors pos-sessed some basic capacities for technological innovationand symbolic behavior before the line leading to Neander-thals in Europe diverged from the line leading to Ana-tomically Modern Humans (AMH) in Africa, a split whichgenetics and archaeology concur in dating to between 400and 800 kya. These more human capacities became moreelaborately expressed earlier in Africa because of its largerpopulation, more diversified landscape, and greater po-tential for interregional interaction. As a result, by 60 kya,AMH entering Eurasia were able to expand and replaceNeanderthals, who responded initially with increased ex-pression of some of these capabilities on their own, butwere ultimately unable to prevail. In the future, new datafrom the fossil and archaeological records but also fromthe evolutionary history ofthe brain, its faculties, and genesthat affect behavior may shed further light on the questionofwhat it means to be human. Alison Brooks at Olorgesailie, Kenya. ReferencesAmbrose, S. 2001. "Paleolithic Technology and HumanEvolution." Science 299 (5509): 1748-53.Anton, S.C., and C.C. Swisher III. 2004. "Early Dispersalsof Homo from Africa." Annual Review of Anthropology 33:271-96.Barham, L.S. 1998. "Possible Early Pigment Use in South-Central Africa." CurrentAnthropology'39: 703-20.Bouzouggar, A., etal. 2007. "82,000-Year-Old Shell Beadsfrom North Africa and Implications for the Origin ofModern Human Behavior." Proceedings of the NationalAcad-emy ofSciences 104: 9964-69.Brooks, A.S. 2010. "What is a Human? AnthropologicalPerspectives on the Origins of Humanness." In M. Jeeves, ed., RethinkingHuman Nature. Eerdmans. In press. (continued on next page) Page 9 inthroNotes Volume 31 No.l Spring 2010 Brooks, A.S., eta/. 2006. "Projectile Technologies of theAfrican MSA: Implications for Modern Human Origins."In E. Hovers and S. Kuhn eds., Transitions before the Transi-tion: Evolution and Stability in the Middle Paleolithic andMiddleStoneAge, pp. 233-55. Kluwer Academics/Plenum.Green, R.E. etal. 2010. 'A draft sequence of the Neandertalgenome." Science'328: 710-722.Henshilwood, C.S., etal. 2004. "Mddle Stone Age beadsfrom South Africa." Science 304: 404. (See supporting onlinematerial for pictures). See also Journal of Human Evolution48, no. 1 (2005): 3-25.Henshilwood, C.S,et al. 2002. "Emergence of ModernHuman Behavior: Engravings from South Africa." Science295: 1278-80.Lieberman, P., and R. C. McCarthy. 2007. "Tracking theevolution of language and speech: Comparing vocal tractsto identify speech capabilities." Expedition 49 (2): 1 5-20.Lordkipanize D, etal. 2005. "Anthropology: The EarliestToothless Hominin Skull." Nature 434: 717-18.Marean C.W., et al 2007. "Early Human Use of MarineResources and Pigment in South Africa during the MddlePleistocene." Nature 449: 905-08.McBrearty, S., and A. Brooks. 2000. "The Revolution ThatWasn't: A New Interpretation of the Origin of ModernHuman Behavior." Journal of Human Evolution 39: 453-563.McDougall, L, F. H. Brown, and J. G. Fleagle. 2005. "Strati-graphic Placement and Age of Modern Humans fromKibish, Ethiopia." Nature 433: 733-36.Mercader, Julio, etal. 2007. "4,300-Year-Old ChimpanzeeSites and the Origins of Percussive Stone Technology."Proceedings of'the National'Academy ofSciences 104 (9): 3043-48.Pearson, Osbjorn M. 2001 . Postcranial Remains and Mod-ern Human Origins. EvolutionaryAnthropology 9 (6): 229-47. Pettitt, Paul A. 2001. "The Neanderthal Dead: ExploringMortuary Variability in Mddle Paleolithic Eurasia." BeforeFarming 1: 1-19. Potts, Richard and Christopher Sloan. 2010. What does itMean to be Human?National Geographic. Roche, H.A., etal. 1999. "Early Hominid Stone Tool Pro-duction and Technical Skill 2.34 Mya in West Turkana,Kenya. Nature 399: 57-60.Semaw, S., M. etal. 2003. "2.6 Million-Year-Old Stone Toolsand Associated Bones from OGS-6 and OGS-7, Gona,Afar, Ethiopia." Journal of Human Evolution 45: 1 69-11 . Sherwood, C. C, E Subiaul, and T Zawidzki. 2008. "ANatural History of the Human Mnd: Tracing Evolution-ary Changes in Brain and Cognition." Journal of Anatomy212 (4): 426-54.Vanhaeren, M., etal. 2006. "Mddle Paleolithic Shell Beadsin Israel and Algeria." Science 312: 1785-88. For a more complete list of references, emailanthroutreach@si.edu. Alison S. Brooks is Professor of Anthropology at GeorgeWashington University and Editor of 'AnthroNotes." Australopithecus afarensis. Starting with a cast skull, artistJohn Gurche builds layers of muscle, fat, and skin to createhyper-realistic busts of human ancestors featured in thenew David H. Koch Hall ofHuman Origins at theSmithsonian's National Museum of Natural History. Page 10