The earliest evidence for anatomically modern humans in northwestern Europe

The earliest anatomically modern humans in Europe are thought to have appeared around 43,000-42,000 calendar years before present (43-42 kyr cal BP), by association with Aurignacian sites and lithic assemblages assumed to have been made by modern humans rather than by Neanderthals. However, the actual physical evidence for modern humans is extremely rare, and direct dates reach no farther back than about 41-39 kyr cal BP, leaving a gap. Here we show, using stratigraphic, chronological and archaeological data, that a fragment of human maxilla from the Kent's Cavern site, UK, dates to the earlier period. The maxilla (KC4), which was excavated in 1927, was initially diagnosed as Upper Palaeolithic modern human. In 1989, it was directly radiocarbon dated by accelerator mass spectrometry to 36.4-34.7 kyr cal BP. Using a Bayesian analysis of new ultrafiltered bone collagen dates in an ordered stratigraphic sequence at the site, we show that this date is a considerable underestimate. Instead, KC4 dates to 44.2-41.5 kyr cal BP. This makes it older than any other equivalently dated modern human specimen and directly contemporary with the latest European Neanderthals, thus making its taxonomic attribution crucial. We also show that in 13 dental traits KC4 possesses modern human rather than Neanderthal characteristics; three other traits show Neanderthal affinities and a further seven are ambiguous. KC4 therefore represents the oldest known anatomically modern human fossil in northwestern Europe, fills a key gap between the earliest dated Aurignacian remains and the earliest human skeletal remains, and demonstrates the wide and rapid dispersal of early modern humans across Europe more than 40 kyr ago.     

A lost Neanderthal neonate found

Fossil remains of adult Neanderthals are well documented, but juvenile specimens are rare and information about them is scant. Here we identify a beautifully preserved skeleton that has been lost to science for almost 90 years as the Neanderthal neonate known as 'Le Moustier 2', which was originally found at Le Moustier in the Dordogne, southwest France. This find will be a rich source of data for studying the evolution of human ontogeny as well as the phylogenetic relationship between these extinct hominids and anatomically modern humans.     

ESR dates for the hominid burial site of Es Skhul in Israel

The Middle East has been critical to our understanding of recent human evolution ever since the recovery of Neanderthal and early anatomically modern fossils from the caves of Tabun and Skhul (Mount Carmel) over 50 years ago. It was generally believed, on archaeological and morphological grounds, that middle eastern Neanderthals (such as those from Tabun, Amud and Kebara) probably dated from more than 50,000 years ago, whereas the earliest anatomically modern specimens (from Skhul and Qafzeh) probably dated from about 40,000 years. Recent thermoluminescence and electron spin resonance (ESR) determinations, however, have supported biostratigraphy in dating the Qafzeh deposits to an earlier part of the late Pleistocene, probably more than 90,000 years ago. These dates have been questioned on unspecified technical grounds, and it has also been argued that they create explanatory problems by separating the morphologically similar Qafzeh and Skhul samples by some 50,000 years, thus implying a long-term coexistence of early modern humans and Neanderthals in the area. Here we report the first radiometric dating analysis for Skhul, using ESR on bovine teeth from the hominid burial levels. Early uptake and linear uptake ages average 81 +/- 15 and 101 +/- 12 kyr respectively. These analyses suggest that the Skhul and Qafzeh samples are of a similar age and therefore it is possible that the presence of early modern humans in the area was episodic, rather than long-term during the early late Pleistocene.     

Early dispersal of modern humans in Europe and implications for Neanderthal behaviour

The appearance of anatomically modern humans in Europe and the nature of the transition from the Middle to Upper Palaeolithic are matters of intense debate. Most researchers accept that before the arrival of anatomically modern humans, Neanderthals had adopted several 'transitional' technocomplexes. Two of these, the Uluzzian of southern Europe and the Chatelperronian of western Europe, are key to current interpretations regarding the timing of arrival of anatomically modern humans in the region and their potential interaction with Neanderthal populations. They are also central to current debates regarding the cognitive abilities of Neanderthals and the reasons behind their extinction. However, the actual fossil evidence associated with these assemblages is scant and fragmentary, and recent work has questioned the attribution of the Chatelperronian to Neanderthals on the basis of taphonomic mixing and lithic analysis. Here we reanalyse the deciduous molars from the Grotta del Cavallo (southern Italy), associated with the Uluzzian and originally classified as Neanderthal. Using two independent morphometric methods based on microtomographic data, we show that the Cavallo specimens can be attributed to anatomically modern humans. The secure context of the teeth provides crucial evidence that the makers of the Uluzzian technocomplex were therefore not Neanderthals. In addition, new chronometric data for the Uluzzian layers of Grotta del Cavallo obtained from associated shell beads and included within a Bayesian age model show that the teeth must date to ~45,000-43,000 calendar years before present. The Cavallo human remains are therefore the oldest known European anatomically modern humans, confirming a rapid dispersal of modern humans across the continent before the Aurignacian and the disappearance of Neanderthals.     

Thermoluminescence dating of the late Neanderthal remains from Saint-Césaire

Anatomically modern humans have long been thought to have been responsible for the Aurignacian and Chatelperronian industries of the early Upper Palaeolithic of Western Europe, whereas the Middle Palaeolithic Mousterian industry has been attributed to Neanderthals. The presence of both Middle and Upper Palaeolithic strata at Saint-Césaire in France offers an excellent opportunity for studying the cultural transition between the two. Saint-Césaire is the only Chatelperronian site that has yielded really diagnostic hominid fossils, and the discovery there of Neanderthal remains alongside Chatelperronian tools cast doubt on the exclusive association between industries and taxon. We report thermoluminescence dates for 20 burnt flints from the site. Those found near the Neanderthal remains were dated at 36,300 +/- 2,700 years BP (before present), making this specimen the youngest Neanderthal dated so far. This date places the stratum close in age to several French but much younger than some Spanish Aurignacian sites believed to have been occupied by modern humans. The possibility of contact between the West European Neanderthals and the intrusive modern humans who replaced them cannot therefore be excluded.     

Analysis of one million base pairs of Neanderthal DNA

Neanderthals are the extinct hominid group most closely related to contemporary humans, so their genome offers a unique opportunity to identify genetic changes specific to anatomically fully modern humans. We have identified a 38,000-year-old Neanderthal fossil that is exceptionally free of contamination from modern human DNA. Direct high-throughput sequencing of a DNA extract from this fossil has thus far yielded over one million base pairs of hominoid nuclear DNA sequences. Comparison with the human and chimpanzee genomes reveals that modern human and Neanderthal DNA sequences diverged on average about 500,000 years ago. Existing technology and fossil resources are now sufficient to initiate a Neanderthal genome-sequencing effort.     

A new radiocarbon revolution and the dispersal of modern humans in Eurasia

Radiocarbon dating has been fundamental to the study of human cultural and biological development over the past 50,000 yr. Two recent developments in the methodology of radiocarbon dating show that the speed of colonization of Europe by modern human populations was more rapid than previously believed, and that their period of coexistence with the preceding Neanderthal was shorter.     

Molecular analysis of Neanderthal DNA from the northern Caucasus

The expansion of premodern humans into western and eastern Europe approximately 40,000 years before the present led to the eventual replacement of the Neanderthals by modern humans approximately 28,000 years ago. Here we report the second mitochondrial DNA (mtDNA) analysis of a Neanderthal, and the first such analysis on clearly dated Neanderthal remains. The specimen is from one of the eastern-most Neanderthal populations, recovered from Mezmaiskaya Cave in the northern Caucasus. Radiocarbon dating estimated the specimen to be approximately 29,000 years old and therefore from one of the latest living Neanderthals. The sequence shows 3.48% divergence from the Feldhofer Neanderthal. Phylogenetic analysis places the two Neanderthals from the Caucasus and western Germany together in a clade that is distinct from modern humans, suggesting that their mtDNA types have not contributed to the modern human mtDNA pool. Comparison with modern populations provides no evidence for the multiregional hypothesis of modern human evolution.     

Human presence in the European Arctic nearly 40,000 years ago.

The transition from the Middle to the Upper Palaeolithic, approximately 40,000-35,000 radiocarbon years ago, marks a turning point in the history of human evolution in Europe. Many changes in the archaeological and fossil record at this time have been associated with the appearance of anatomically modern humans. Before this transition, the Neanderthals roamed the continent, but their remains have not been found in the northernmost part of Eurasia. It is generally believed that this vast region was not colonized by humans until the final stage of the last Ice Age some 13,000-14,000 years ago. Here we report the discovery of traces of human occupation nearly 40,000 years old at Mamontovaya Kurya, a Palaeolithic site situated in the European part of the Russian Arctic. At this site we have uncovered stone artefacts, animal bones and a mammoth tusk with human-made marks from strata covered by thick Quaternary deposits. This is the oldest documented evidence for human presence at this high latitude; it implies that either the Neanderthals expanded much further north than previously thought or that modern humans were present in the Arctic only a few thousand years after their first appearance in Europe.     

How Neanderthal molar teeth grew

Growth and development are both fundamental components of demographic structure and life history strategy. Together with information about developmental timing they ultimately contribute to a better understanding of Neanderthal extinction. Primate molar tooth development tracks the pace of life history evolution most closely, and tooth histology reveals a record of birth as well as the timing of crown and root growth. High-resolution micro-computed tomography now allows us to image complex structures and uncover subtle differences in adult tooth morphology that are determined early in embryonic development. Here we show that the timing of molar crown and root completion in Neanderthals matches those known for modern humans but that a more complex enamel-dentine junction morphology and a late peak in root extension rate sets them apart. Previous predictions about Neanderthal growth, based only on anterior tooth surfaces, were necessarily speculative. These data are the first on internal molar microstructure; they firmly place key Neanderthal life history variables within those known for modern humans.     

Stratigraphic placement and age of modern humans from Kibish, Ethiopia

In 1967 the Kibish Formation in southern Ethiopia yielded hominid cranial remains identified as early anatomically modern humans, assigned to Homo sapiens. However, the provenance and age of the fossils have been much debated. Here we confirm that the Omo I and Omo II hominid fossils are from similar stratigraphic levels in Member I of the Kibish Formation, despite the view that Omo I is more modern in appearance than Omo II. 40Ar/39Ar ages on feldspar crystals from pumice clasts within a tuff in Member I below the hominid levels place an older limit of 198 +/- 14 kyr (weighted mean age 196 +/- 2 kyr) on the hominids. A younger age limit of 104 +/- 7 kyr is provided by feldspars from pumice clasts in a Member III tuff. Geological evidence indicates rapid deposition of each member of the Kibish Formation. Isotopic ages on the Kibish Formation correspond to ages of Mediterranean sapropels, which reflect increased flow of the Nile River, and necessarily increased flow of the Omo River. Thus the 40Ar/39Ar age measurements, together with the sapropel correlations, indicate that the hominid fossils have an age close to the older limit. Our preferred estimate of the age of the Kibish hominids is 195 +/- 5 kyr, making them the earliest well-dated anatomically modern humans yet described.     

Pleistocene Homo sapiens from Middle Awash,Ethiopia

The origin of anatomically modern Homo sapiens and the fate of Neanderthals have been fundamental questions in human evolutionary studies for over a century. A key barrier to the resolution of these questions has been the lack of substantial and accurately dated African hominid fossils from between 100,000 and 300,000 years ago. Here we describe fossilized hominid crania from Herto, Middle Awash, Ethiopia, that fill this gap and provide crucial evidence on the location, timing and contextual circumstances of the emergence of Homo sapiens. Radioisotopically dated to between 160,000 and 154,000 years ago, these new fossils predate classic Neanderthals and lack their derived features. The Herto hominids are morphologically and chronologically intermediate between archaic African fossils and later anatomically modern Late Pleistocene humans. They therefore represent the probable immediate ancestors of anatomically modern humans. Their anatomy and antiquity constitute strong evidence of modern-human emergence in Africa.     

Neanderthals and the modern human colonization of Europe

The fate of the Neanderthal populations of Europe and western Asia has gripped the popular and scientific imaginations for the past century. Following at least 200,000 years of successful adaptation to the glacial climates of northwestern Eurasia, they disappeared abruptly between 30,000 and 40,000 years ago, to be replaced by populations all but identical to modern humans. Recent research suggests that the roots of this dramatic population replacement can be traced far back to events on another continent, with the appearance of distinctively modern human remains and artefacts in eastern and southern Africa.     

Neanderthal cranial ontogeny and its implications for late hominid diversity

Homo neanderthalensis has a unique combination of craniofacial features that are distinct from fossil and extant 'anatomically modern' Homo sapiens (modern humans). Morphological evidence, direct isotopic dates and fossil mitochondrial DNA from three Neanderthals indicate that the Neanderthals were a separate evolutionary lineage for at least 500,000 yr. However, it is unknown when and how Neanderthal craniofacial autapomorphies (unique, derived characters) emerged during ontogeny. Here we use computerized fossil reconstruction and geometric morphometrics to show that characteristic differences in cranial and mandibular shape between Neanderthals and modern humans arose very early during development, possibly prenatally, and were maintained throughout postnatal ontogeny. Postnatal differences in cranial ontogeny between the two taxa are characterized primarily by heterochronic modifications of a common spatial pattern of development. Evidence for early ontogenetic divergence together with evolutionary stasis of taxon-specific patterns of ontogeny is consistent with separation of Neanderthals and modern humans at the species level.     

Placing late Neanderthals in a climatic context

Attempts to place Palaeolithic finds within a precise climatic framework are complicated by both uncertainty over the radiocarbon calibration beyond about 21,500 14C years bp and the absence of a master calendar chronology for climate events from reference archives such as Greenland ice cores or speleothems. Here we present an alternative approach, in which 14C dates of interest are mapped directly onto the palaeoclimate record of the Cariaco Basin by means of its 14C series, circumventing calendar age model and correlation uncertainties, and placing dated events in the millennial-scale climate context of the last glacial period. This is applied to different sets of dates from levels with Mousterian artefacts, presumably produced by late Neanderthals, from Gorham's Cave in Gibraltar: first, generally accepted estimates of about 32,000 14C years bp for the uppermost Mousterian levels; second, a possible extended Middle Palaeolithic occupation until about 28,000 14C years bp; and third, more contentious evidence for persistence until about 24,000 14C years bp. This study shows that the three sets translate to different scenarios on the role of climate in Neanderthal extinction. The first two correspond to intervals of general climatic instability between stadials and interstadials that characterized most of the Middle Pleniglacial and are not coeval with Heinrich Events. In contrast, if accepted, the youngest date indicates that late Neanderthals may have persisted up to the onset of a major environmental shift, which included an expansion in global ice volume and an increased latitudinal temperature gradient. More generally, our radiocarbon climatostratigraphic approach can be applied to any 'snapshot' date from discontinuous records in a variety of deposits and can become a powerful tool in evaluating the climatic signature of critical intervals in Late Pleistocene human evolution.     

Stratigraphic,chronological and behavioural contexts of Pleistocene Homo sapiens from Middle Awash,Ethiopia

Clarifying the geographic, environmental and behavioural contexts in which the emergence of anatomically modern Homo sapiens occurred has proved difficult, particularly because Africa lacked adequate geochronological, palaeontological and archaeological evidence. The discovery of anatomically modern Homo sapiens fossils at Herto, Ethiopia, changes this. Here we report on stratigraphically associated Late Middle Pleistocene artefacts and fossils from fluvial and lake margin sandstones of the Upper Herto Member of the Bouri Formation, Middle Awash, Afar Rift, Ethiopia. The fossils and artefacts are dated between 160,000 and 154,000 years ago by precise age determinations using the 40Ar/39Ar method. The archaeological assemblages contain elements of both Acheulean and Middle Stone Age technocomplexes. Associated faunal remains indicate repeated, systematic butchery of hippopotamus carcasses. Contemporary adult and juvenile Homo sapiens fossil crania manifest bone modifications indicative of deliberate mortuary practices.     

Variations of Younger Dryas atmospheric radiocarbon explicable without ocean circulation changes

The concentration of radiocarbon, 14C, in the atmosphere depends on its production rate by cosmic rays, and on the intensity of carbon exchange between the atmosphere and other reservoirs, for example the deep oceans. For the Holocene (the past approximately 11,500 years), it has been shown that fluctuations in atmospheric radiocarbon concentrations have been caused mostly by variations in the solar magnetic field. Recent progress in extending the radiocarbon record backwards in time has indicated especially high atmospheric radiocarbon concentrations in the Younger Dryas cold period, between 12,700 and 11,500 years before the present. These high concentrations have been interpreted as a result of a reduced exchange with the deep-ocean reservoir, caused by a drastic weakening of the deep-ocean ventilation. Here we present a high-resolution reconstruction of atmospheric radiocarbon concentrations, derived from annually laminated sediments of two Polish lakes, Lake Gosciaz and Lake Perespilno. These records indicate that the maximum in atmospheric radiocarbon concentrations in the early Younger Dryas was smaller than previously believed, and might have been caused by variations in solar activity. If so, there is no indication that the deep-ocean ventilation in the Younger Dryas was significantly different from today's.     

Archaeology and age of a new hominin from Flores in eastern Indonesia

Excavations at Liang Bua, a large limestone cave on the island of Flores in eastern Indonesia, have yielded evidence for a population of tiny hominins, sufficiently distinct anatomically to be assigned to a new species, Homo floresiensis. The finds comprise the cranial and some post-cranial remains of one individual, as well as a premolar from another individual in older deposits. Here we describe their context, implications and the remaining archaeological uncertainties. Dating by radiocarbon (14C), luminescence, uranium-series and electron spin resonance (ESR) methods indicates that H. floresiensis existed from before 38,000 years ago (kyr) until at least 18 kyr. Associated deposits contain stone artefacts and animal remains, including Komodo dragon and an endemic, dwarfed species of Stegodon. H. floresiensis originated from an early dispersal of Homo erectus (including specimens referred to as Homo ergaster and Homo georgicus) that reached Flores, and then survived on this island refuge until relatively recently. It overlapped significantly in time with Homo sapiens in the region, but we do not know if or how the two species interacted.     

Reburial of fossil organic carbon in marine sediments

Marine sediments act as the ultimate sink for organic carbon, sequestering otherwise rapidly cycling carbon for geologic timescales. Sedimentary organic carbon burial appears to be controlled by oxygen exposure time in situ, and much research has focused on understanding the mechanisms of preservation of organic carbon. In this context, combustion-derived black carbon has received attention as a form of refractory organic carbon that may be preferentially preserved in soils and sediments. However, little is understood about the environmental roles, transport and distribution of black carbon. Here we apply isotopic analyses to graphitic black carbon samples isolated from pre-industrial marine and terrestrial sediments. We find that this material is terrestrially derived and almost entirely depleted of radiocarbon, suggesting that it is graphite weathered from rocks, rather than a combustion product. The widespread presence of fossil graphitic black carbon in sediments has therefore probably led to significant overestimates of burial of combustion-derived black carbon in marine sediments. It could be responsible for biasing radiocarbon dating of sedimentary organic carbon, and also reveals a closed loop in the carbon cycle. Depending on its susceptibility to oxidation, this recycled carbon may be locked away from the biologically mediated carbon cycle for many geologic cycles.     

Direct dating of Early Upper Palaeolithic human remains from Mladec

The human fossil assemblage from the Mladec Caves in Moravia (Czech Republic) has been considered to derive from a middle or later phase of the Central European Aurignacian period on the basis of archaeological remains (a few stone artefacts and organic items such as bone points, awls, perforated teeth), despite questions of association between the human fossils and the archaeological materials and concerning the chronological implications of the limited archaeological remains. The morphological variability in the human assemblage, the presence of apparently archaic features in some specimens, and the assumed early date of the remains have made this fossil assemblage pivotal in assessments of modern human emergence within Europe. We present here the first successful direct accelerator mass spectrometry radiocarbon dating of five representative human fossils from the site. We selected sample materials from teeth and from one bone for 14C dating. The four tooth samples yielded uncalibrated ages of approximately 31,000 14C years before present, and the bone sample (an ulna) provided an uncertain more-recent age. These data are sufficient to confirm that the Mladec human assemblage is the oldest cranial, dental and postcranial assemblage of early modern humans in Europe and is therefore central to discussions of modern human emergence in the northwestern Old World and the fate of the Neanderthals.