The archeology of modern human origins

Two competing hypotheses have long dominated specialist thinking on modern human origins. The first posits that modern people emerged in a limited area and spread from there to replace archaic people elsewhere. Proponents of this view currently favor Africa as the modern human birthplace.^1–5 The second suggests that the evolution of modern humans was not geographically restricted, but invlved substantial continuity between archaic and modern populations in all major regions of the occupied world.^6–7 Based solely on the fossil record, both hypotheses are equally defensible, but the spread-and-replationships scenario is far more strongly supported by burgeoning data on the genetic relationships and diversity of living humans.^8–16 These data impy that there was a common ancestor for all living humans in Africa between 280,000 and 140,000 year ago, and that Neanderthals and other archaic humans who inhabited Eurasia during the same interval contributed few, if any, genes to living peiple. I argue here that the spread-and-replacement hypothesis is also more compatible with a third line of evidence: the spread-and-replacement hypothesis is also more compatible with a third line of evidence: the archeological record for human behavioral evolution.     

Glacial cycling, large mammal community composition, and trophic adaptations in the Western Cape, South Africa

Some of the earliest evidence for modern human behavior has been recovered from the Western Cape Province, South Africa. Archaeological and paleontological sites in the Western Cape are typically described as “glacial” or “interglacial” in aspect based on the numbers of grazers found in the faunal assemblage, as glacial periods are often thought to have been characterized by spreading C₄ grasslands that replaced endemic C₃ shrubland vegetation found in the Western Cape today. Here, we test the hypothesis that glacial and interglacial time periods were associated with a predictable change in large mammal trophic adaptations by analyzing the proportions of grazing larger mammals from 118 levels of 15 Western Cape fossil assemblages sampling marine isotope stage (MIS) 6 to the present time to determine whether there is a change in composition in these communities that might reflect a shift in ecology and habitat. Our results indicate that trophic proportions did not significantly change over time in the Western Cape as a whole, and thus the hypothesis for habitat changes affecting the subsistence ecology of modern humans during the development of modern behavior is not supported. However, our results show that the southwestern subregion of the Western Cape was characterized by the presence of more grazing species through time than the western subregion. Thus, if ecological and population isolation during glacial periods were integral to catalyzing the development of modern behaviors in the Western Cape region of South Africa, then a complex model including the development of possible mosaic habitats is needed.     

The Pleistocene archaeology and environments of the Wasiriya Beds, Rusinga Island, Kenya

Western Kenya is well known for abundant early Miocene hominoid fossils. However, the Wasiriya Beds of Rusinga Island, Kenya, preserve a Pleistocene sedimentary archive with radiocarbon age estimates of >33–45 ka that contains Middle Stone Age artifacts and abundant, well-preserved fossil fauna: a co-occurrence rare in eastern Africa, particularly in the region bounding Lake Victoria. Artifacts and fossils are associated with distal volcanic ash deposits that occur at multiple localities in the Wasiriya Beds, correlated on the basis of geochemical composition as determined by electron probe microanalysis. Sediment lithology and the fossil ungulates suggest a local fluvial system and associated riparian wooded habitat within a predominantly arid grassland setting that differs substantially from the modern environment, where local climate is strongly affected by moisture availability from Lake Victoria. In particular, the presence of oryx (Oryx gazella) and Grevy’s zebra (Equus grevyi) suggest a pre-Last Glacial Maximum expansion of arid grasslands, an environmental reconstruction further supported by the presence of several extinct specialized grazers (Pelorovis antiquus, Megalotragus sp., and a small alcelaphine) that are unknown from Holocene deposits in eastern Africa. The combination of artifacts, a rich fossil fauna, and volcaniclastic sediments makes the Wasiriya Beds a key site for examining the Lake Victoria basin, a biogeographically important area for understanding the diversification and dispersal of Homo sapiens from Africa, whose pre-Last Glacial Maximum history remains poorly understood.     

Une vue d’ensemble sur Melka Kunture,grand complexe de sites pléistocènes dans la vallée supérieure de l’Awash (Éthiopie)

Melka Kunture is a cluster of Pleistocene sites, extending over ?100 km² between 2000 and 2200 m asl, in the upper Awash Valley of Ethiopia. Starting around 2 million-years ago, the archaeological sequence includes sites with lithic productions of the Oldowan, Early Acheulean, middle Acheulean, final Acheulean, Early Middle Stone Age, Middle Stone Age and Late Stone Age. All over the Pleistocene, the climate was rainy and cooler than at the lower elevations of the Rift Valley, allowing the development of Afromontane vegetation. Hippopotamuses are ubiquitous and dominant in terms of biomass, but Alcelaphini are well represented, notably with genus Connochaetes and genus Damaliscus. Hominin fossils have been discovered in association with the Oldowan, the Early Acheulean, the middle Acheulean and the Early Middle Stone Age. Animal tracks and hominin footprints have also been documented, the latter ones in layers dated between 1.2 and 0.7 million-years.     

Extending the chronology of deposits at Blombos Cave, South Africa, back to 140 ka using optical dating of single and multiple grains of quartz

Optically stimulated luminescence (OSL) measurements are reported for both single aliquots (of two different sizes) and single grains of quartz from deposits within Blombos Cave. Ages have been obtained for six sediments from the Middle Stone Age (MSA) occupation levels and for two sterile sands, one underlying the archaeological sediment and one overlying the Later Stone Age occupation levels. The ages for the archaeological sediments were obtained from single-grain measurements that enabled unrepresentative grains to be rejected. The MSA occupation levels have ages that, within error limits, are in stratigraphic order and fall between the OSL age for the oldest dune sand (143.2+/-5.5 ka) and a previously published OSL age for the sterile sand ( approximately 70 ka) that separates the Middle and Later Stone Age deposits. The earliest MSA archaeological phase, M3, from where fragments of ochre were found as well as human teeth, is dated to 98.9+/-4.5 ka, coinciding with the sea-level high of oxygen isotope substage 5c. The cave then appears to be unoccupied until oxygen isotope substage 5a on the basis of four OSL ages for archaeological phase M2, ranging from 84.6+/-5.8 to 76.8+/-3.1 ka; these levels contained large hearths and bone tools. An age of 72.7+/-3.1 ka was obtained for the final MSA archaeological phase, M1, from which deliberately engraved ochre and shell beads were recovered along with bifacial stone points. We conclude that the periods of occupation were determined by changes in sea level, with abundant sources of seafood available in times of high sea level and with the cave being closed by the accumulation of large dunes during periods of low sea level, such as during oxygen isotope stages 4 and 6.     

Taphonomic and paleoecological change in the large mammal sequence from Boomplaas Cave,western Cape,South Africa

Excavations conducted by H.J. Deacon in the 1970s at Boomplaas Cave (BPA) uncovered a stratified sequence of Middle Stone Age (MSA) and Later Stone Age (LSA) deposits spanning the last >65,000 years. This study provides the first comprehensive and integrated taphonomic and paleoecological analysis of the BPA large mammals, with a focus on its implications for understanding human adaptations and environmental changes in southern Africa's Cape Floristic Region (CFR), an area that features prominently in understanding modern human origins. Taphonomic data indicate a complex history of human, carnivore, and raptor accumulation of the large mammal assemblage. The anthropogenic signal is largely absent from the bottom of the sequence (>65,000 years ago), intermediate in MSA and LSA assemblages from ∼50,000 to 20,000 years ago, and strong in LSA deposits post-dating the Last Glacial Maximum (LGM). When viewed in the broader CFR context, the inferred occupation history of BPA is consistent with the hypothesis that both MSA and LSA human populations were concentrated on the submerged coastline from ∼60,000 to ∼20,000 years ago. Intensive occupation following the LGM parallels an apparent increase in regional population densities, which may have been driven in part by rising sea levels. The BPA ungulate assemblage is characterized by the rise and decline of a taxonomically diverse grazing community, which peaks during the LGM. These changes are not correlated with taphonomic shifts, meaning that they are likely driven by environmental factors, namely the expansion and contraction of grassland habitats. Changes in ungulate diversity indicate that effective precipitation was highest during the LGM, corresponding with an intensified winter rainfall system. This is consistent with recent arguments that the LGM in this region may not have been extremely harsh and arid.     

Human remains from Blombos Cave, South Africa: (1997-1998 excavations)

The Middle Stone Age (MSA) layers at Blombos Cave contain abundant bifacial Still Bay points, formal and ad hoc bone artefacts, and an intentionally incised bone piece. These artefacts add weight to arguments that some aspects of modern human behavior developed earlier in sub-Saharan Africa than elsewhere. Four human teeth were recovered from the MSA strata at Blombos during the 1997-1998 excavations. Two are heavily worn deciduous teeth, and two are incomplete permanent premolar crowns. The Blombos di(1)is comparatively large in relation to modern African homologues, falling within the lower part of the observed Neandertal range. The dm(1)and P(3)are comparable to modern teeth and smaller than most Neandertal crowns. The premolars preserve horizontal circum-cervical striae that suggest palliative toothpick use. The di(1)evinces labial scratches that resemble neither the "cutmarks" that have been observed on Neandertal incisors, nor the striae that have been recorded on modern human teeth.     

Human molars from later Pleistocene deposits of Witkrans Cave,Gaap Escarpment,Kalahari Margin

Human molars from travertine deposits of Witkrans Cave (Gaap Escarpment, northern Cape Province, South Africa) are described. The Witkrans molars were discovered in direct association with later Pleistocene faunal remains and a sample of Middle Stone Age artifacts (Peabody, 1954; Clark, 1971; Sampson, 1974; Klein, 1984; Volman, 1984). The morphology and dimensions of the Witkrans molars resemble remains from other localities of similar age in southern Africa (Singer & Wymer, 1982; Grine & Klein, 1985; Grine et al., 1991; Rightmire & Deacon 1991) but exhibit differences from later Pleistocene occurrences in northern Africa (McBurney et al. 1953; Vallois & Roche, 1958; Ennouchi, 1969; Hublin & Tillier, 1981). These results offer further support for the existence of later Pleistocene human populations south of the Sahara which were distinct from contemporaneous peoples of Mediterranean Africa (Howell, 1978; Brauer, 1984; Rightmire, 1984; Klein 1992).     

The gripping nature of ochre: the association of ochre with Howiesons Poort adhesives and Later Stone Age mastics from South Africa

This contribution provides direct evidence for the use of ochre in adhesive recipes during the Howiesons Poort of South Africa. Stone segments from two KwaZulu-Natal sites were microscopically analyzed to document ochre and resin microresidue occurrences. These microresidues show a clear distribution pattern on the tool portions that are associated with hafting. Results from a separate quartz and crystal-quartz sample may indicate that different adhesive recipes were applied to different raw materials. A possible functional application for ochre in association with Later Stone Age mastics is also explored. The evidence and suggestions presented here expand our understanding of the versatility, use, and value of pigmentatious materials in prehistory; it is not viewed as an alternative or replacement hypothesis for its possible symbolic role during the late Pleistocene.     

Hominid molars from a Middle Stone Age level at the Mumba Rock Shelter, Tanzania

Three hominid molars were recovered from a depth of 7.0-7.1 meters in the Mumba Shelter at Lake Eyasi, northern Tanzania. Geological context of the finds and archaeological data indicate that people with a Middle Stone Age technology were using the Mumba locality intermittently whenever retreat of lake waters allowed access to the site. Uranium series dates suggest an age on the order of 130,000 years bp for the teeth and stone tools. Based on morphological analyses, the dental remains probably belonged to one individual and appear to be the crowns of two upper permanent M2s and one lower permanent M2. Crown areas are very small, even in comparison to the variation exhibited by recent African populations. Crown patterns have no archaic features. These teeth are smaller than any verifiable archaic Homo sapiens examples; thus, they may represent early anatomically modern Homo sapiens.     

Announcing a Still Bay industry at Sibudu Cave, South Africa

Sibudu Cave in KwaZulu-Natal, South Africa, has a long Middle Stone Age (MSA) sequence with good organic preservation. The uppermost MSA sequence includes industries attributed to the final and late MSA and the Howiesons Poort. Below the Howiesons Poort are two layers containing some thin, bifacial lanceolate points, mostly in the form of distal and proximal fragments. These double-pointed foliates are the fossile directeur of the Still Bay Industry, and importantly, this Sibudu industry provides confirmation that the Still Bay predates the Howiesons Poort Industry. Technologically, the points from Sibudu are comparable to those from other South African sites with Still Bay occurrences (e.g., Blombos Cave and Hollow Rock Shelter). Although dating of the Sibudu Still Bay is preliminary, its age falls within the range of that at Blombos. For the past two decades, archaeologists have rejected the idea of a Still Bay Industry occurring outside of the Western Cape, but the Still Bay at Sibudu shows that this industry was, indeed, geographically widespread.     

Multivariate perspectives on change and continuity in the Middle Stone Age lithics from Klasies River Mouth, South Africa

This paper examines variability and the emergence of the Howiesons Poort within the Middle Stone Age lithic technologies of Klasies River Mouth. Here I present a pattern recognition study using multivariate statistical techniques examining the data presented by [Singer, R., Wymer, J.J., 1982. The Middle Stone Age at Klasies River Mouth in South Africa. Chicago University Press, Chicago]. Using this model, the Middle Stone Age (MSA) lithics from Klasies River Mouth load on three main factors: (1) a Levallois flake manufacture factor, (2) a blade manufacture factor, and (3) a worked point factor. The MSA I assemblage from Cave 1 and the MSA II assemblage from Shelter 1a correlate strongly with the worked point factor, the MSA II assemblage from Cave 1 correlates strongly with the Levallois factor, and the Howiesons Poort assemblage from Shelter 1a correlates strongly with the blade factor. The Howiesons Poort from Shelter 1a is differs more from all other industries than the remaining industries do from each other. In addition, the Howiesons Poort from Cave 2 groups closely with the MSA III assemblage from Shelter 1a due to similarities in raw material frequencies.     

Intrasite spatial variation of the Omo Kibish Middle Stone Age assemblages: artifact refitting and distribution patterns

The middle-late Pleistocene Kibish Formation of the Lower Omo Valley (Ethiopia) contains some of the oldest dated Homo sapiens fossils. Archaeological excavations at the Omo Kibish between 2002 and 2003 recovered numerous stone tools from extensive horizontal exposures of two sites, KHS (dated to 195 ± 5 kyr) and BNS (dated to at least 104 ± 7 kyr). Analysis of artifact distributions, lithic-debris densities, and refitting artifact sets sheds light on site-formation processes. Both localities reveal weak patterns of differentiation, and BNS seems to have a preferred refit orientation.     

Les occupations humaines du Nord du Maroc,du Paléolithique Moyen et du Paléolithique Supérieur. Nouvelles données sur la base des recherches archéologiques des projets de 2005 à 2020

In this work, we present a synthetic panorama of the human occupations of northern Morocco, with an emphasis on the association of anthropological with cultural records, within the framework of the Middle Palaeolithic (MSA) and the Upper Palaeolithic. We also present the projects developed over the past 15 years and the most interesting results we have obtained. And we conclude bay providing some reflections on the cultural and historical evaluation of the archaeological records from the Tetouan region in the Middle and the Upper Palaeolithic phases.     

The invisible frontier. A multiple species model for the origin of behavioral modernity

Two contradictory theories of human cognitive evolution have been developed to model how, when, and among what hominid groups behavioral modernity emerged. The first model, which has long been the dominant paradigm, links these behavioral innovations to a cultural “revolution” by anatomically modern humans in Europe at around 40,000 years ago, coinciding with the first arrival of our species in this region.^1–4 According to this model, the sudden and explosive character of this change is demonstrated by the appearance in the archeological record of previously unseen carvings, personal ornaments, musical instruments, depictions on cave walls, and new stone and bone technology. A variant of this model sees behavioral modernity resulting from a rapid biological change, a brain mutation producing no apparent change in skull anatomy, which occurred in Europe or, more probably, in Africa at ca. 50,000 years ago.⁵⁶.     

Des silicites dans le Paléolithique ancien et moyen du Maroc occidental

A first diachronic examination of the use of silicites by Early and Middle Palaeolithic hominins in the Moroccan Meseta is presented. An in-depth study of the origins of the different geo-materials was carried on series from five recently excavated sites in northern Meseta at Casablanca — Unit L and Grotte à Hominidés at Thomas Quarry I, Grotte des Rhinocéros and Grotte des Gazelles — and in the southern Meseta at Djebel Irhoud cave. They show that flints from the Phosphates Plateau were the most widely used, from the earliest moments of the Early Palaeolithic (at least 1.3 Ma), but their predominant use for lithic artefacts coincides here with the appearance of the MSA (around 0.35 Ma).