Developmental pathways inferred from modularity, morphological integration and fluctuating asymmetry patterns in the human face

Facial asymmetries are usually measured and interpreted as proxies to developmental noise. However, analyses focused on its developmental and genetic architecture are scarce. To advance on this topic, studies based on a comprehensive and simultaneous analysis of modularity, morphological integration and facial asymmetries including both phenotypic and genomic information are needed. Here we explore several modularity hypotheses on a sample of Latin American mestizos, in order to test if modularity and integration patterns difer across several genomic ancestry backgrounds. To do so, 4104 individuals were analyzed using 3D photogrammetry reconstructions and a set of 34 facial landmarks placed on each individual. We found a pattern of modularity and integration that is conserved across sub-samples difering in their genomic ancestry background. Specifcally, a signal of modularity based on functional demands and organization of the face is regularly observed across the whole sample. Our results shed more light on previous evidence obtained from Genome Wide Association Studies performed on the same samples, indicating the action of diferent genomic regions contributing to the expression of the nose and mouth facial phenotypes. Our results also indicate that large samples including phenotypic and genomic metadata enable a better understanding of the developmental and genetic architecture of craniofacial phenotypes

The Oldest Case of Decapitation in the New World (Lapa do Santo, East-Central Brazil)

We present here evidence for an early Holocene case of decapitation in the New World (Burial 26), found in the rock shelter of Lapa do Santo in 2007. Lapa do Santo is an archaeological site located in the Lagoa Santa karst in east-central Brazil with evidence of human occupation dating as far back as 11.7-12.7 cal kyBP (95.4% interval). An ultra-filtered AMS age determination on a fragment of the sphenoid provided an age range of 9.1-9.4 cal kyBP (95.4% interval) for Burial 26. The interment was composed of an articulated cranium, mandible and first six cervical vertebrae. Cut marks with a v-shaped profile were observed in the mandible and sixth cervical vertebra. The right hand was amputated and laid over the left side of the face with distal phalanges pointing to the chin and the left hand was amputated and laid over the right side of the face with distal phalanges pointing to the forehead. Strontium analysis comparing Burial 26's isotopic signature to other specimens from Lapa do Santo suggests this was a local member of the group. Therefore, we suggest a ritualized decapitation instead of trophy-taking, testifying for the sophistication of mortuary rituals among hunter-gatherers in the Americas during the early Archaic period. In the apparent absence of wealth goods or elaborated architecture, Lapa do Santo's inhabitants seemed to use the human body to express their cosmological principles regarding death

Lack of support for the association between facial shape and aggression: a reappraisal based on a worldwide population genetics perspective

Antisocial and criminal behaviors are multifactorial traits whose interpretation relies on multiple disciplines. Since these interpretations may have social, moral and legal implications, a constant review of the evidence is necessary before any scientific claim is considered as truth. A recent study proposed that men with wider faces relative to facial height (fWHR) are more likely to develop unethical behaviour mediated by a psychological sense of power. This research was based on reports suggesting that sexual dimorphism and selection would be responsible for a correlation between fWHR and aggression. Here we show that 4,960 individuals from 94 modern human populations belonging to a vast array of genetic and cultural contexts do not display significant amounts of fWHR sexual dimorphism. Further analyses using populations with associated ethnographical records as well as samples of male prisoners of the Mexico City Federal Penitentiary condemned by crimes of variable level of inter-personal aggression (homicide, robbery, and minor faults) did not show significant evidence, suggesting that populations/individuals with higher levels of bellicosity, aggressive behaviour, or power-mediated behaviour display greater fWHR. Finally, a regression analysis of fWHR on individual"s fitness showed no significant correlation between this facial trait and reproductive success. Overall, our results suggest that facial attributes are poor predictors of aggressive behaviour, or at least, that sexual selection was weak enough to leave a signal on patterns of between- and within-sex and population facial variation

Caso de Fribroma osificante en caballo

A case of ossifying fibroma has been described in the jaw of filly of 3 months of age of Pure spanish breed. The mass, of rapid growth, was located in the pertaining to the rostral jaw region nearby to the extreme incisor tooth. The radiological image shows radiolucid limited areas and neoformation osseous, displacement of the dental pieces and projection towards the interior of bone radiodensity 3, presenting radiopaque lines. Microscopically, the superficial area has necrosis with abundant bacteria, neutrophils and vascular thromboses. The middle and deep zones present a very cellular connective tissue constituted by cells similar to fibroblast cells, and fundamental substance that shows a pre-osseous structure. Between bands of connective tissue, bony tissue perfectly differentiated with the presence of osteoblast, osteocyte and osteoclast cells are observed. The observations of the histopathologic study confirm the diagnosis of ossifying fibroma. This tumor of strange presentation in horse, in spite of it benign characteristics, presents reserved evolution and prognosis.Una potra de pura raza española de 3 meses de edad y no destetada ingresó en el Hospital Clínico Veterinario por la presencia de una masa de rápido crecimiento en la región antero-lateral mandibular derecha. Las imágenes radiológicas mostraron zonas radiolúcidas localizando la tumoración a nivel del incisivo extremo y extendiéndose 5cm dentro de la rama de la mandíbula. Macroscópicamente se observó como un crecimiento que hace protución en la boca de color marrón-grisáceo de consistencia firme extendiéndose desde el borde del incisivo extremo derecho. El análisis microscópico reveló amplias áreas de necrosis, bacterias y un infiltrado de polimorfos nucleares neutrófilos. Otras regiones se caracterizaron por la presencia de un tejido conectivo con abundante sustancia amorfa y fibroblastos, presentando espículas óseas con osteoclastos y zonas de matriz calcificada. Fueron múltiples las imágenes mitóticas y se observó escasa anaplasia celular. Las características descriptas ofrecen datos anatomopatológicos correspondientes con un fibroma osificante, de rara presentación en equinos, si bien existen contradicciones en la bibliografía acerca de su pronóstico y evolución