Dental evidence for ontogenetic differences between modern humans and Neanderthals

Humans have an unusual life history, with an early weaning age, long childhood, late first reproduction, short interbirth intervals, and long lifespan. In contrast, great apes wean later, reproduce earlier, and have longer intervals between births. Despite 80 y of speculation, the origins of these developmental patterns in Homo sapiens remain unknown. Because they record daily growth during formation, teeth provide important insights, revealing that australopithecines and early Homo had more rapid ontogenies than recent humans. Dental development in later Homo species has been intensely debated, most notably the issue of whether Neanderthals and H. sapiens differ. Here we apply synchrotron virtual histology to a geographically and temporally diverse sample of Middle Paleolithic juveniles, including Neanderthals, to assess tooth formation and calculate age at death from dental microstructure. We find that most Neanderthal tooth crowns grew more rapidly than modern human teeth, resulting in significantly faster dental maturation. In contrast, Middle Paleolithic H. sapiens juveniles show greater similarity to recent humans. These findings are consistent with recent cranial and molecular evidence for subtle developmental differences between Neanderthals and H. sapiens. When compared with earlier hominin taxa, both Neanderthals and H. sapiens have extended the duration of dental development. This period of dental immaturity is particularly prolonged in modern humans.Human Evolutionary Biolog

The extraordinary evolutionary history of the reticuloendotheliosis viruses

The reticuloendotheliosis viruses (REVs) comprise several closely related amphotropic retroviruses isolated from birds. These viruses exhibit several highly unusual characteristics that have not so far been adequately explained, including their extremely close relationship to mammalian retroviruses, and their presence as endogenous sequences within the genomes of certain large DNA viruses. We present evidence for an iatrogenic origin of REVs that accounts for these phenomena. Firstly, we identify endogenous retroviral fossils in mammalian genomes that share a unique recombinant structure with REVs—unequivocally demonstrating that REVs derive directly from mammalian retroviruses. Secondly, through sequencing of archived REV isolates, we confirm that contaminated Plasmodium lophurae stocks have been the source of multiple REV outbreaks in experimentally infected birds. Finally, we show that both phylogenetic and historical evidence support a scenario wherein REVs originated as mammalian retroviruses that were accidentally introduced into avian hosts in the late 1930s, during experimental studies of P. lophurae, and subsequently integrated into the fowlpox virus (FWPV) and gallid herpesvirus type 2 (GHV-2) genomes, generating recombinant DNA viruses that now circulate in wild birds and poultry. Our findings provide a novel perspective on the origin and evolution of REV, and indicate that horizontal gene transfer between virus families can expand the impact of iatrogenic transmission events

Homo naledi, a new species of the genus Homo from the Dinaledi Chamber, South Africa.

Homo naledi is a previously-unknown species of extinct hominin discovered within the Dinaledi Chamber of the Rising Star cave system, Cradle of Humankind, South Africa. This species is characterized by body mass and stature similar to small-bodied human populations but a small endocranial volume similar to australopiths. Cranial morphology of H. naledi is unique, but most similar to early Homo species including Homo erectus, Homo habilis or Homo rudolfensis. While primitive, the dentition is generally small and simple in occlusal morphology. H. naledi has humanlike manipulatory adaptations of the hand and wrist. It also exhibits a humanlike foot and lower limb. These humanlike aspects are contrasted in the postcrania with a more primitive or australopith-like trunk, shoulder, pelvis and proximal femur. Representing at least 15 individuals with most skeletal elements repeated multiple times, this is the largest assemblage of a single species of hominins yet discovered in Africa

Factors influencing parents' decision on their children's vaccination against seasonal influenza : a systematic review

Introduction: Seasonal influenza is believed to be a common attribution of morbidity and mortality in the children population, and it causes huge disease burden worldwide. Although seasonal influenza vaccination is recommended as the most effective prevention by the World Health Organization and vaccination programs for children have been introduced in many countries, vaccination coverage remains low. Parents are primary decision makers for their children's immunization, therefore it is important to understand the determinants that influence parents' decision-making to provide important information for promoting vaccination uptake against seasonal influenza among children. Objective: To synthesize factors that influence parental decision on children's vaccination against seasonal influenza from published literature. Method: Literature reported factors that influenced parental decision on children's vaccination against seasonal influenza published before/on 31th May, 2013 were searched in PubMed and Web of Science databases. Manual searching was also performed for the citations of the retrieved papers. Both qualitative and quantitative articles consistent with the objective were searched from PubMed and Web of Science databases on 31th May, 2013. Records were screened in the sequence of title, abstract and full text to identify eligible studies, and references of eligible studies were also scrutinized to avoid missing important articles. Influencing factors were extracted from included papers, and the identified factors that influenced parental decision making were then discussed based on theoretical behavioral models. Results: Totally 32 articles met the inclusion criteria. Factors associated with parental decision included demographic factors, which consisted of parental and children’s age, parental gender, ethnicity, household income, residence, insurance status, family characters, parental education level, and children’s health history; psychological factors, including attitudes towards influenza vaccination, knowledge of influenza and vaccination, perceived risk of seasonal influenza, and emotional factors; past behaviors comprising previous frequency of using health care services, children’s seasonal influenza vaccination history, previous absenteeism from school or work, social norm referring cues to action and subjective norms; and environmental factors, meaning access to vaccination facilities. Discussion: An integrated framework based on the Health Belief Model, Triandis’ Theory of Interpersonal Behavior and the Theory of Reasoned Action was constructed to explain the findings. The framework proposes that the parents’ intention to vaccinate their children against seasonal influenza is influenced by demographic variables, attitude towards seasonal influenza vaccination, knowledge and perception of influenza/influenza vaccine, social norms (cues to action and subjective norms), emotion, and past behavior/experience; easy access to vaccination providers as a facilitating condition additionally determine the possibility of turning intention into actual behavior. Interventions such as providing positive knowledge relevant to seasonal influenza vaccination, targeting less intended and more influential decision-makers, ensuring sufficient access to vaccination, and creating action cues may be implemented to promote uptake of seasonal influenza vaccination among children.published_or_final_versionPublic HealthMasterMaster of Public Healt

More than 500.000 years of right- handedness in Europe.

10.1080/1357650X.2010.529451Considerable research supports the high frequency of right-handedness in living Homo sapiens, with worldwide rates of approximately nine right- for every one left-hander. Right-handedness appears to be a uniquely human trait, as no other primate species, no matter how proficient in tool use, shows frequencies even close to the strong right bias typical of humans (Cashmore, Uomini, & Chapelain, 2008; McGrew & Marchant 1997; Steele & Uomini, 2009). Here we review our research on human fossils from Sima de los Huesos (Atapuerca, Spain) and their likely descendants, the European Neandertals. We document hand preference in fossils by scratch patterns that occur on the labial (lip) face of incisors and canines, and contend that these patterns provide a reliable means for identifying predominant hand use in these samples. Manipulatory marks on the anterior teeth show a persistent pattern of right-handed actions, implying that the modern human pattern of dominant right-handedness extends deep into the European past

Nuove evidenze dell’evoluzione umana in Europa durante il Pleistocene. Implicazioni filogenetiche e comportamentali

Vengono focalizzati i caratteri biologici e culturali delle popolazioni europee durante le fasi di transizione fra i primi abitanti e i Neandertaliani e fra questi ultimi e i primi Uomini moderni