A genetic history of the Balkans from Roman frontier to Slavic migrations.

The rise and fall of the Roman Empire was a socio-political process with enormous ramifications for human history. The Middle Danube was a crucial frontier and a crossroads for population and cultural movement. Here, we present genome-wide data from 136 Balkan individuals dated to the 1st millennium CE. Despite extensive militarization and cultural influence, we find little ancestry contribution from peoples of Italic descent. However, we trace a large-scale influx of people of Anatolian ancestry during the Imperial period. Between ∼250 and 550 CE, we detect migrants with ancestry from Central/Northern Europe and the Steppe, confirming that "barbarian" migrations were propelled by ethnically diverse confederations. Following the end of Roman control, we detect the large-scale arrival of individuals who were genetically similar to modern Eastern European Slavic-speaking populations, who contributed 30%-60% of the ancestry of Balkan people, representing one of the largest permanent demographic changes anywhere in Europe during the Migration Period.

Homo bodoensis and why it matters.

In our original paper, we proposed a new species, Homo bodoensis, to replace the problematical taxa Homo heidelbergensis and Homo rhodesiensis, with the goal of streamlining communication about human evolution in the Chibanian. We received two independent responses. Given their substantial overlap, we provide one combined reply. In this response: (1) we are encouraged that the primary proposal in our paper, to discontinue the use of H. heidelbergensis (as a junior synonym to Homo neanderthalensis) due to its' nomenclatural problems, is acknowledged. (2) we provide additional clarification about the rules governing taxonomic nomenclature as outlined by the International Code of Zoological Nomenclature and join the growing calls for a revision to these rules. (3) we discuss further why H. rhodesiensis should be abandoned, particularly in light of the current sensitivity to using culturally inappropriate names. We conclude that H. bodoensis is a better solution than the proposed alternatives.

Early Neanderthals in contact: The Chibanian (Middle Pleistocene) hominin dentition from Velika Balanica Cave, Southern Serbia.

Neanderthals are Eurasian fossil hominins whose distinctive morphology developed in the southwestern corner of Europe and later spread throughout the continent, reaching Southwest Asia before the Late Pleistocene and spreading into Central Asia by 59-49 ka. The timing, tempo, and route of the Neanderthal movements eastward are poorly documented. The earliest probable evidence of Neanderthals in Asia comes from Karain E Cave (Anatolia, Turkey), dated to 250-200 ka. We present four Chibanian (Middle Pleistocene) hominin specimens, representing at least two individuals, from Velika Balanica Cave (Serbia): a permanent upper third molar (BH-2), a deciduous upper fourth premolar (BH-3) refitted to a poorly preserved maxillary fragment with the permanent first molar in the alveolus (BH-4), and a permanent upper central incisor (BH-5). We provide descriptions of the teeth, as well as a comparative analysis of the well-preserved M1 (BH-4), including assessments of cusp angles, relative occlusal polygon area, relative cusp base areas, two- and three-dimensional enamel thickness, and taurodontism. Morphology of both the occlusal surface and the enamel dentine junction of the M1 indicates that the maxillary fragment and associated dP4 belonged to an early Neanderthal child. The heavily worn I1 and M3 are consistent with the Neanderthal morphology, although they are less distinct taxonomically. These Chibanian remains with provenance from layer 3a are constrained by two thermoluminescence dates: 285 ± 34 ka and 295 ± 74 ka. They represent the earliest current evidence of Neanderthal spread into the Eastern Mediterranean Area. We discuss these findings in light of recent direct evidence for cultural connections between Southwestern Asia and Southeast Europe in the Chibanian.

Connections between the Levant and the Balkans in the late Middle Pleistocene: Archaeological findings from Velika and Mala Balanica Caves (Serbia).

Major changes in the technological, economic, and social behavior of Middle Pleistocene hominins occurred at the onset of the Middle Paleolithic, 400-200 ka. However, until recently it was not possible to establish when, where, and how certain forms of Middle Paleolithic behavior appeared and spread into Southeastern Europe, mainly owing to gaps in the Paleolithic record. Here we report new results of dating, material culture, and the archaeological context of finds from the Balanica Cave Complex in Sicevo (Serbia). Two methods-thermoluminescence and electron spin resonance-were used to date the sequence. The geoarchaeological context was examined through sedimentology, micromorphology, and spatial analysis. Microfaunal remains were used to constrain the dates within an ecological zone, whereas macrofauna was analyzed for taxonomy and taphonomy to examine the source of accumulation and hominin behavior. Technological and typological features of the lithic assemblage were used to characterize lithic production at the site. Materials recovered from Layer 3 in Velika Balanica and from Layer 2 in Mala Balanica, both dated to MIS 9-7, include a distinctive set of archaeological assemblages which resemble contemporaneous Yabrudian assemblages from the Levant in important ways, and which are unlike contemporary material from the surrounding regions. In Velika Balanica, the lithic assemblages are associated with a large fireplace containing evidence of human activities similar to those from Qesem Cave (Israel). Dental remains uncovered in the same layer are consistent with Neanderthals. These findings suggest that the end of the Middle Pleistocene (before 300-240 ka) saw population movement and/or cultural transmission between Southwest Asia and the Balkans, which led eventually to a transfer of technology between Middle Eastern and European hominin populations and contributed to the shaping of Neanderthal behaviors throughout the eastern and northern Mediterranean.

Resolving the "muddle in the middle": The case for Homo bodoensis sp. nov.

Recent developments in the field of palaeoanthropology necessitate the suppression of two hominin taxa and the introduction of a new species of hominins to help resolve the current nebulous state of Middle Pleistocene (Chibanian) hominin taxonomy. In particular, the poorly defined and variably understood hominin taxa Homo heidelbergensis (both sensu stricto and sensu lato) and Homo rhodesiensis need to be abandoned as they fail to reflect the full range of hominin variability in the Middle Pleistocene. Instead, we propose: (1) introduction of a new taxon, Homo bodoensis sp. nov., as an early Middle Pleistocene ancestor of the Homo sapiens lineage, with a pan-African distribution that extends into the eastern Mediterranean (Southeast Europe and the Levant); (2) that many of the fossils from Western Europe (e.g. Sima de los Huesos) currently assigned to H. heidelbergensis s.s. be reassigned to Homo neanderthalensis to reflect the early appearance of Neanderthal derived traits in the Middle Pleistocene in the region; and (3) that the Middle Pleistocene Asian fossils, particularly from China, likely represent a different lineage altogether.

The evolution and changing ecology of the African hominid oral microbiome.

The oral microbiome plays key roles in human biology, health, and disease, but little is known about the global diversity, variation, or evolution of this microbial community. To better understand the evolution and changing ecology of the human oral microbiome, we analyzed 124 dental biofilm metagenomes from humans, including Neanderthals and Late Pleistocene to present-day modern humans, chimpanzees, and gorillas, as well as New World howler monkeys for comparison. We find that a core microbiome of primarily biofilm structural taxa has been maintained throughout African hominid evolution, and these microbial groups are also shared with howler monkeys, suggesting that they have been important oral members since before the catarrhine-platyrrhine split ca. 40 Mya. However, community structure and individual microbial phylogenies do not closely reflect host relationships, and the dental biofilms of Homo and chimpanzees are distinguished by major taxonomic and functional differences. Reconstructing oral metagenomes from up to 100 thousand years ago, we show that the microbial profiles of both Neanderthals and modern humans are highly similar, sharing functional adaptations in nutrient metabolism. These include an apparent Homo-specific acquisition of salivary amylase-binding capability by oral streptococci, suggesting microbial coadaptation with host diet. We additionally find evidence of shared genetic diversity in the oral bacteria of Neanderthal and Upper Paleolithic modern humans that is not observed in later modern human populations. Differences in the oral microbiomes of African hominids provide insights into human evolution, the ancestral state of the human microbiome, and a temporal framework for understanding microbial health and disease.

Genomic insights into the early peopling of the Caribbean.

The Caribbean was one of the last regions of the Americas to be settled by humans, but where they came from and how and when they reached the islands remain unclear. We generated genome-wide data for 93 ancient Caribbean islanders dating between 3200 and 400 calibrated years before the present and found evidence of at least three separate dispersals into the region, including two early dispersals into the Western Caribbean, one of which seems connected to radiation events in North America. This was followed by a later expansion from South America. We also detected genetic differences between the early settlers and the newcomers from South America, with almost no evidence of admixture. Our results add to our understanding of the initial peopling of the Caribbean and the movements of Archaic Age peoples in the Americas.

First record of a fossil monkey (Primates, Cercopithecidae) from the Late Pliocene of Serbia.

The cercopithecid fossil record of the Balkan Peninsula extends from the Late Miocene to the Early Pleistocene, but to date no fossils of non-human primates have been identified in Serbia. Here we report the identification of two primate teeth from Ridjake, a rich paleontological site in western Serbia. NHMBEO 042501 is an upper third molar with heavy occlusal wear and taphonomic weathering. NHMBEO 042502 is a well-preserved lower third molar with only minor damage to the cusps and root apices. We performed an analysis of non-metric traits and made bivariate comparisons of crown linear measurements in order to assess the taxonomic affinity of the molars. Both show typical papionin occlusal patterns and relatively large overall sizes. In combination with the early Villafranchian (MN16) age of the site, we attribute both Ridjake primate fossils to cf. Paradolichopithecus sp. This represents the first identification of a non-human primate in Serbia, and the first identification of any primate in the Neogene period of Serbia. Along with recent hominin discoveries, the Ridjake fossils contribute to the growing primate fossil record in Serbia, and indicate the need for increased research into fossil primates in the country.

The first Neanderthal specimen from Serbia: Maxillary first molar from the Late Pleistocene of Pesturina Cave.

Neanderthals were the only human group in Europe throughout the Late Pleistocene until the arrival of modern humans, and while their presence has been confirmed in the surrounding regions, no Neanderthal fossils are known to date from the Central Balkans. Systematic excavations of Pesturina Cave (Serbia) resulted in the discovery of a permanent right M1 (Pes-3). The specimen was recovered from stratigraphic Layer 4b with an estimated age of 102.4 ± 3.2 ka, associated with Mousterian artifacts. The exceptional state of preservation and minimal wear of the molar enabled a detailed description and comparative analysis of the inner and outer dental structure, including non-metric dental traits and morphometric features of the crown, roots, and dental tissues. The results of this study strongly support the identification of Pes-3 as Neanderthal. Non-metric traits of the occlusal surface of the crown, enamel-dentine junction, and roots are consistent with Neanderthal morphology. The crown shows morphometric features typical for Neanderthal M1, such as a buccolingually skewed crown shape, internally compressed cusps, and a relatively large hypocone. The specimen also shows Neanderthal-like dental tissue proportions, characterized by relatively thin enamel and large coronal dentine and coronal pulp volumes. The discovery of the Pes-3 molar therefore confirms the presence of Neanderthals in the territory of Serbia and the Central Balkans at the end of Marine Isotope Stage (MIS) 5c.

Isotopic reconstruction of the weaning process in the archaeological population of Canímar Abajo, Cuba: A Bayesian probability mixing model approach.

The general lack of well-preserved juvenile skeletal remains from Caribbean archaeological sites has, in the past, prevented evaluations of juvenile dietary changes. Canímar Abajo (Cuba), with a large number of well-preserved juvenile and adult skeletal remains, provided a unique opportunity to fully assess juvenile paleodiets from an ancient Caribbean population. Ages for the start and the end of weaning and possible food sources used for weaning were inferred by combining the results of two Bayesian probability models that help to reduce some of the uncertainties inherent to bone collagen isotope based paleodiet reconstructions. Bone collagen (31 juveniles, 18 adult females) was used for carbon and nitrogen isotope analyses. The isotope results were assessed using two Bayesian probability models: Weaning Ages Reconstruction with Nitrogen isotopes and Stable Isotope Analyses in R. Breast milk seems to have been the most important protein source until two years of age with some supplementary food such as tropical fruits and root cultigens likely introduced earlier. After two, juvenile diets were likely continuously supplemented by starch rich foods such as root cultigens and legumes. By the age of three, the model results suggest that the weaning process was completed. Additional indications suggest that animal marine/riverine protein and maize, while part of the Canímar Abajo female diets, were likely not used to supplement juvenile diets. The combined use of both models here provided a more complete assessment of the weaning process for an ancient Caribbean population, indicating not only the start and end ages of weaning but also the relative importance of different food sources for different age juveniles.

Not of African Descent: Dental Modification among Indigenous Caribbean People from Canímar Abajo, Cuba.

Dental modifications in the Caribbean are considered to be an African practice introduced to the Caribbean archipelago by the influx of enslaved Africans during colonial times. Skeletal remains which exhibited dental modifications are by default considered to be Africans, African descendants, or post-contact indigenous people influenced by an African practice. Individual E-105 from the site of Canímar Abajo (Cuba), with a direct 14C AMS date of 990-800 cal BC, provides the first unequivocal evidence of dental modifications in the Antilles prior to contact with Europeans in AD 1492. Central incisors showing evidence of significant crown reduction (loss of crown volume regardless of its etiology) were examined macroscopically and with a scanning electron microscope (SEM) to determine if the observed alterations were due to deliberate modification or other (unintentional) factors considered: postmortem breakage, violent accidental breakage, non-dietary use of teeth, and wear caused by habitual or repeated actions. The pattern of crown reduction is consistent with deliberate dental modification of the type commonly encountered among African and African descendent communities in post-contact Caribbean archaeological assemblages. Six additional individuals show similar pattern of crown reduction of maxillary incisors with no analogous wear in corresponding mandibular dentition.

A dental perspective on the taxonomic affinity of the Balanica mandible (BH-1).

The Middle Pleistocene represents a period of critical importance in human evolution, marked by encephalisation and dental reduction, and increasing diversification of temporally and spatially distributed hominin lineages in Africa, Asia and Europe. New specimens, especially from areas less well represented in the fossil record, can inform the debate on morphological changes to the skeleton and teeth and the phylogenetic course of human evolution during this period. The mandible from the cave of Mala Balanica, Serbia has recently been re-dated to at least 400 ka, and its well-preserved dentition presents an excellent opportunity to characterize molar crown morphology at this time period, and re-examine claims for a lack of Neandertal affinities in the specimen. In this study we employ microtomography to image the internal structure of the mandibular molars (focusing on the morphology of the enamel-dentine junction, or EDJ) of the BH-1 specimen and a comparative sample (n = 141) of Homo erectus sensu lato, Homo neanderthalensis, Pleistocene Homo sapiens, and recent H. sapiens. We quantitatively assess EDJ morphology using 3D geometric morphometrics and examine the expression of discrete dental traits at the dentine surface. We also compare third molar enamel thickness in BH-1 to those of H. neanderthalensis and both Pleistocene and recent H. sapiens, and document previously unreported morphology of the BH-1 premolar and molar roots. Our results highlight the reliability of the EDJ surface for classifying hominin taxa, indicate a primitive dental morphology for BH-1 molars, and confirm a general lack of derived Neandertal features for the Balanica individual. The plesiomorphic character of BH-1 is consistent with several competing models of Middle Pleistocene hominin evolution and provides an important regional and temporal example for reconstructing morphological changes in the mandible and teeth during this time period.

A re-examination of the human fossil specimen from Backi Petrovac (Serbia).

A fragmented human calotte was discovered during the early 1950s near Backi Petrovac (Serbia), in association with Palaeolithic stone tools. After its initial publication, the fossil specimen remained largely unknown outside of the Serbian academe and no detailed comparative study has ever been carried out. Since the whereabouts of the fossil itself are currently unknown, and given its potential significance for the Pleistocene human evolution, we re-examine the data published by Zivanovic (1966, 1975). Using the original measurements, mostly taken on the frontal bone, and a wide comparative sample of 68 fossil specimens, the fossil was compared and analyzed by statistical multivariate methods. We also conducted a visual examination of the morphology based on the available photographic material. Our analysis reveals phenetic similarity with Middle Pleistocene archaic Homo from Africa and anatomically modern Homo sapiens. However, the absence of primitive cranial traits in Backi Petrovac indicates a clear modern Homo sapiens designation. Although lost at the moment, there is a chance for the re-discovery of the fossil in the years to come. This would give us an opportunity to acquire absolute dates and to study the specimen in a more detailed manner.

New radiometric ages for the BH-1 hominin from Balanica (Serbia): implications for understanding the role of the Balkans in Middle Pleistocene human evolution.

Newly obtained ages, based on electron spin resonance combined with uranium series isotopic analysis, and infrared/post-infrared luminescence dating, provide a minimum age that lies between 397 and 525 ka for the hominin mandible BH-1 from Mala Balanica cave, Serbia. This confirms it as the easternmost hominin specimen in Europe dated to the Middle Pleistocene. Inferences drawn from the morphology of the mandible BH-1 place it outside currently observed variation of European Homo heidelbergensis. The lack of derived Neandertal traits in BH-1 and its contemporary specimens in Southeast Europe, such as Kocabas, Vasogliano and Ceprano, coupled with Middle Pleistocene synapomorphies, suggests different evolutionary forces acting in the east of the continent where isolation did not play such an important role during glaciations.

Spina bifida in a pre-Columbian Cuban population: A paleoepidemiological study of genetic and dietary risk factors.

A holistic approach is necessary to investigate health in archeological populations. Molecular techniques, particularly multiplex PCR and SNaPshot minisequencing, can be combined with paleopathology and dietary analysis (stable isotope, starch, zooarchaeological analyses) to understand aspects of population health. This article demonstrates how spina bifida, a multi-factorial disease characterized by the midline failure to complete vertebral neural arch formation, can be investigated holistically. Based on skeletal evidence, this disease was prevalent in a pre-Columbian Cuban population from the archeological site of Canimar Abajo (3000-1250 BP). Molecular paleopathological techniques were employed to examine disease potential in this preliminary study, examining 18 individuals (including two individuals with evidence of mild spina bifida, and 16 without such evidence) for four single nucleotide polymorphisms and one insertion sequence associated with spina bifida. The combined effect of these polymorphisms, as well as dietary factors, determines the risk of the population for spina bifida, and these factors united to create the observed high disease prevalence. We demonstrate how molecular paleopathology, corroborated by dietary analyses, can be used within a paleoepidemiological framework to understand population health and disease.

A human mandible (BH-1) from the Pleistocene deposits of Mala Balanica cave (Sicevo Gorge, Nis, Serbia).

Neandertals and their immediate predecessors are commonly considered to be the only humans inhabiting Europe in the Middle and early Late Pleistocene. Most Middle Pleistocene western European specimens show evidence of a developing Neandertal morphology, supporting the notion that these traits evolved at the extreme West of the continent due, at least partially, to the isolation produced by glacial events. The recent discovery of a mandible, BH-1, from Mala Balanica (Serbia), with primitive character states comparable with Early Pleistocene mandibular specimens, is associated with a minimum radiometric date of 113 + 72 - 43 ka. Given the fragmented nature of the hemi-mandible and the fact that primitive character states preclude assignment to a species, the taxonomic status of the specimen is best described as an archaic Homo sp. The combination of primitive traits and a possible Late Pleistocene date suggests that a more primitive morphology, one that does not show Neandertal traits, could have persisted in the region. Different hominin morphologies could have survived and coexisted in the Balkans, the "hotspot of biodiversity." This first hominin specimen to come from a secure stratigraphic context in the Central Balkans indicates a potentially important role for the region in understanding human evolution in Europe that will only be resolved with more concentrated research efforts in the area.

Using the life history model to set the stage(s) of growth and senescence in bioarchaeology and paleodemography.

Paleodemography, the study of demographic parameters of past human populations, relies on assumptions including biological uniformitarianism, stationary populations, and the ability to determine point age estimates from skeletal material. These assumptions have been widely criticized in the literature and various solutions have been proposed. The majority of these solutions rely on statistical modeling, and have not seen widespread application. Most bioarchaeologists recognize that our ability to assess chronological age is inherently limited, and have instead resorted to large, qualitative, age categories. However, there has been little attempt in the literature to systematize and define the stages of development and ageing used in bioarchaeology. We propose that stages should be based in the human life history pattern, and their skeletal markers should have easily defined and clear endpoints. In addition to a standard five-stage developmental model based on the human life history pattern, current among human biologists, we suggest divisions within the adult stage that recognize the specific nature of skeletal samples. We therefore propose the following eight stages recognizable in human skeletal development and senescence: infancy, early childhood, late childhood, adolescence, young adulthood, full adulthood, mature adulthood, and senile adulthood. Striving toward a better prediction of chronological ages will remain important and could eventually help us understand to what extent past societies differed in the timing of these life stages. Furthermore, paleodemographers should try to develop methods that rely on the type of age information accessible from the skeletal material, which uses life stages, rather than point age estimates.