Multi-proxy analysis suggests Late Pleistocene affinities of human skeletal remains attributed to Balzi Rossi.

In two publications from 1967 and 1971, M. Masali described human skeletal remains presumed to have been found in the Balzi Rossi caves (Ventimiglia, Italy), based on a signed note dated to 1908. Since then, the remains - dubbed "Conio's Finds" and preserved at the University of Torino - had not been further studied. We performed a multidisciplinary investigation aimed at clarifying the geographical and chronological attribution of these specimens. Collagen extraction for AMS dating was unsuccessful, but we obtained two direct dates on the best- preserved crania via 231Pa/235U direct gamma-ray spectrometry (10,500±2,000 years BP and 12,500±2,500 years BP). We analyzed the metrics and morphology of the crania and femora by comparing them with samples belonging to the Upper Paleolithic, Mesolithic, and Neolithic periods, and evidenced that the "Conio's Finds" are morphologically more compatible with a Late Pleistocene rather than Holocene attribution. We analyzed the literature regarding the history of excavations at Balzi Rossi, and we propose that - if any credence should be given to the note accompanying the material - the remains may have been found in front of Grotta dei Fanciulli or Grotta del Caviglione, in the redeposited soil dug up during the installation of lime kilns carried out between the late 18th and the early 19th centuries. These hypotheses may be tested in the future by comparing the speleothem deposited on one of the crania and the remaining deposit at the site.

Neurocranial development of the coelacanth and the evolution of the sarcopterygian head.

The neurocranium of sarcopterygian fishes was originally divided into an anterior (ethmosphenoid) and posterior (otoccipital) portion by an intracranial joint, and underwent major changes in its overall geometry before fusing into a single unit in lungfishes and early tetrapods1. Although the pattern of these changes is well-documented, the developmental mechanisms that underpin variation in the form of the neurocranium and its associated soft tissues during the evolution of sarcopterygian fishes remain poorly understood. The coelacanth Latimeria is the only known living vertebrate that retains an intracranial joint2,3. Despite its importance for understanding neurocranial evolution, the development of the neurocranium of this ovoviviparous fish remains unknown. Here we investigate the ontogeny of the neurocranium and brain in Latimeria chalumnae using conventional and synchrotron X-ray micro-computed tomography as well as magnetic resonance imaging, performed on an extensive growth series for this species. We describe the neurocranium at the earliest developmental stage known for Latimeria, as well as the major changes that the neurocranium undergoes during ontogeny. Changes in the neurocranium are associated with an extreme reduction in the relative size of the brain along with an enlargement of the notochord. The development of the notochord appears to have a major effect on the surrounding cranial components, and might underpin the formation of the intracranial joint. Our results shed light on the interplay between the neurocranium and its adjacent soft tissues during development in Latimeria, and provide insights into the developmental mechanisms that are likely to have underpinned the evolution of neurocranial diversity in sarcopterygian fishes.

Morphological variability of Upper Paleolithic and Mesolithic skulls from Sicily.

Scenarios for the dispersal of Homo sapiens in Southern Europe and in the Mediterranean basin have been uncertain, given the scarceness of osteological samples and the simplicity of the proposed archaeologically-based settlement hypotheses. According to available data, the first anatomically modern humans entered Sicily during the Late Pleistocene, coming from the Italian peninsula. A presumably small Late Epigravettian population colonised coastal sites. Later, North-Western archaeological horizons gave hospitality to a significant Mesolithic expansion. In order to verify a hypothesis of continuity in the peopling of the island, we analyzed Sicilian skulls from the Late Epigravettian site of San Teodoro, Eastern Sicily (AMS 14C dated at 14,500 BP) and from the Mesolithic period (14C dated from 9,500 to 8,500 BP) coming from various sites (Uzzo, Molara, Grotta d'Oriente) located on the North Western coast of the island. The aims were to test the biological variability through time within the island as well as to evaluate the relationships of Sicilian Pleistocene hunter-gatherers with Old World populations. We also evaluated the Sicilian Mesolithic uniformity especially between the Uzzo and Grotta d'Oriente sites, given their vicinity and accessibility during the Early Holocene. We applied 3D geometric morphometric methods to assess shape variation as well as geographic and diachronic morphological patterns. All analyzed specimens, plus a comparative sample from the Old World dated from the Upper Paleolithic to recent periods, were transformed in digital images and standard craniofacial landmarks were extracted from the 3D models. Our results underline a high variability among the Mesolithic specimens, as well as a large craniometric distance from the presumed founder Paleolithic settler representatives (San Teodoro specimens) that have closer morphological affinities with other European Upper Paleolithic specimens.

Dental phenotypic shape variation supports a multiple dispersal model for anatomically modern humans in Southeast Asia.

The population history of anatomically modern humans (AMH) in Southeast Asia (SEA) is a highly debated topic. The impact of sea level variations related to the Last Glacial Maximum (LGM) and the Neolithic diffusion on past population dispersals are two key issues. We have investigated competing AMH dispersal hypotheses in SEA through the analysis of dental phenotype shape variation on the basis of very large archaeological samples employing two complementary approaches. We first explored the structure of between- and within-group shape variation of permanent human molar crowns. Second, we undertook a direct test of competing hypotheses through a modeling approach. Our results identify a significant LGM-mediated AMH expansion and a strong biological impact of the spread of Neolithic farmers into SEA during the Holocene. The present work thus favors a "multiple AMH dispersal" hypothesis for the population history of SEA, reconciling phenotypic and recent genomic data.

11,000 years of craniofacial and mandibular variation in Lower Nubia.

The transition to agriculture was a key event in human history. The extent to which this transition is associated with biological changes in different world regions remains debated. Cultural and osteological records in Lower Nubia throughout the Holocene have been interpreted as a result of in situ differentiation or alternatively as migratory events and possible admixture with surrounding populations. Here we investigated the patterns of craniofacial and mandibular variation from Mesolithic hunting-gathering to late farming, a period spanning 11,000 years. We analyzed 102 adult specimens spanning five cultural horizons: Mesolithic, A-group, C-group, Pharaonic and Meroitic, by means of 3D geometric morphometric methods, in order to assess shape variation and diachronic patterns at the transition to farming and in subsequent periods. Our results highlight a strong morphometric distinction between Mesolithic hunter-gatherers and farmers as well as differences between transitional and intensive farmers in mandibular variation which is consistent with differential impact of selective pressures on different regions of the skull. This study corroborates a major biological change during the transition from hunting to farming, supporting the masticatory-functional hypothesis for the mandible and suggesting population continuity among farming populations throughout the Holocene based on the overall shape of the cranium.

A three-dimensional geometric morphometrics view of the cranial shape variation and population history in the New World.

OBJECTIVES: Craniofacial variation in past and present Amerindians has been attributed to the effect of multiple founder events, or to one major migration followed by in situ differentiation and possibly recurrent contacts among Circum-Arctic groups. Our study aims to: (i) detect morphological differences that may indicate several migrations; (ii) test for the presence of genetic isolation; and (iii) test the correlation between shape data and competing settlement hypotheses by taking into account geography, chronology, climate effects, the presence of genetic isolation and recurrent gene flow. METHODS: We analyzed a large sample of three-dimensional (3D) cranial surface scans (803 specimens) including past and modern groups from America and Australasia. Shape variation was investigated using geometric morphometrics. Differential external gene flow was evaluated by applying genetic concepts to morphometric data (Relethford-Blangero approach). Settlement hypotheses were tested using a matrix correlation approach (Mantel tests). RESULTS: Our results highlight the strong dichotomy between Circum-Arctic and continental Amerindians as well as the impact of climate adaptation, and possibly recurrent gene flow in the Circum-Arctic area. There is also evidence for the impact of genetic isolation on phenetic variation in Baja California. Several settlement hypotheses are correlated with our data. CONCLUSIONS: The three approaches used in this study highlight the importance of local processes especially in Baja California, and caution against the use of overly simplistic models when searching for the number of migration events. The results stress the complexity of the settlement of the Americas as well as the mosaic nature of the processes involved in this process. Am. J. Hum. Biol. 28:646-661, 2016. © 2016 Wiley Periodicals, Inc.