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.

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Using Schutkowski's method for juvenile sex determination (Schutkowski H. 1993. Am J Phys Anthropol 90:199-205), we evaluated the morphology of the greater sciatic notch of 56 ilia (23 females and 33 males) from a documented skeletal collection housed at the Bocage Museum in Lisbon (Portugal). After applying Schutkowski's original methodology and comparing the results with previous studies, we used age-adjusted metrical variables to describe greater sciatic notch depth, breadth, and angle. Although results of both morphological and metrical analyses did not reveal a statistically significant level of sexual analyses dimorphism, we found a strong correlation between pelvic morphology and age at death. On the basis of the obtained results, we argue that Schutkowski's morphological method does not predict sex accurately in all populations and that recorded correlation of iliac features with age needs to be further explored in the context of the ontogeny of sexual dimorphism.

Ancient DNA traces the history of hepatitis B Hepatitis B virus (HBV) infections represent a worldwide human health concern. To study the history of this pathogen, Kocher et al . identified 137 human remains with detectable levels of virus dating between 400 and 10,000 years ago. Sequencing and analyses of these ancient viruses suggested a common ancestor between 12,000 and 20,000 years ago. There is no evidence indicating that HBV was present in the earliest humans as they spread out of Africa; however, HBV was likely present in human populations before farming. Furthermore, the virus was present in the Americas by about 9000 years ago, representing a lineage sister to the viral strains found in Eurasia that diverged about 20,000 years ago. —LMZ

Archaeological investigations in the Iron Gates reach of the Lower Danube Valley between 1964 and 1984 revealed an important concentration of Stone Age sites, which together provide the most detailed record of Mesolithic and Early Neolithic settlement from any area of southeastern Europe. Over 425 human burials were excavated from 15 sites. Of these, less than one-fifth have been directly dated. This article presents 37 new AMS dates on human bone from five sites in the Iron Gates, together with the corresponding δ 13 C and δ 15 N values. They include the first dates on human bone from two sites, Icoana and Velesnica. The results are important for the chronology of Stone Age mortuary practices in the Iron Gates and the timing of the Mesolithic-Neolithic transition in the region.

The Caribbean was one of the last regions of the Americas to be settled by humans, but how, when, and from where they reached the islands remains unclear. We generated genome-wide data for 93 ancient Caribbean islanders dating between 3200-400 cal. BP and find 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 detect 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.

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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.