Estudio comparativo de las cavidades del oído externo, medio e interno y establecimiento de la potencia sonora en Homínidos

Esta tesis se ha realizado atendiendo a dos objetivos principales: completar el estudio de las cavidades del oído de los fósiles del yacimiento de la Sima de los Huesos (SH) y extender el estudio de las cavidades del oído externo y medio (OEM) al conjunto de la subfamilia Homininae. Para ello, se han realizado las reconstrucciones tridimensionales de las cavidades del oído de 21 ejemplares de Gorilla gorilla, 9 de SH y 7 de Homo neanderthalensis. En relación con el primer objetivo, se han realizado tres trabajos que se han publicado en la revista Journal of Human Evolution. En el primero, se ha realizado el estudio comparado de los canales semicirculares del fósil mesopleistoceno Aroeira 3 (Portugal) con los ejemplares de SH. El principal resultado es el establecimiento de que, pese a su proximidad geográfica y temporal, Aroeira 3 presenta una morfología más primitiva que la de los fósiles de SH, que ya presentan rasgos de tipo neandertal. Este resultado indica el aislamiento de las poblaciones humanas de la península ibérica durante el Estadio isotópico MIS 12. El segundo trabajo publicado consiste en un detallado estudio comparativo de las cócleas de SH con muestras de Pan troglodytes, Homo sapiens y H. neanderthalensis. También se han incluido datos de Australopithecus africanus, Paranthropus robustus, y de homínidos obtenidos de la bibliografía. Las cócleas de SH muestran un patrón evolutivo en mosaico con rasgos primitivos, compartidos con P. troglodytes, y otros derivados del género Homo, compartidos con H. neanderthalensis y H. sapiens. También se ha propuesto la existencia de homoplasias entre la cóclea de los neandertales y la de nuestra especie en aquellos rasgos compartidos por ambas especies en los que los fósiles de SH presentan el estado primitivo. La inferencia realizada sobre los límites de la audición de los fósiles de SH, a partir del valor de su volumen coclear, indican que su límite superior estaba algo desplazado hacia frecuencias más altas que los de H. neanderthalensis y H. sapiens. El estudio de las capacidades auditivas del Cráneo 4 de SH constituye el tercer trabajo publicado de esta tesis. Este ejemplar había sido diagnosticado como el caso más antiguo conocido de sordera en la evolución humana por presentar exostosis bilateral de sus conductos auditivos externos. Los resultados del trabajo muestran claramente que el individuo representado por el Cráneo 4 no vio afectada su audición por las exostosis de sus conductos auditivos externos, por lo que el diagnóstico de sordera ha sido refutado. Las investigaciones efectuadas en relación con el segundo objetivo constituyen la sección inédita de esta tesis. Se ha realizado el estudio comparado de la anatomía del OEM de G. gorilla, P. troglodytes, los fósiles de SH, H. neanderthalensis y H. sapiens. Se han caracterizado los OEM de las diferentes especies y se ha hecho una propuesta de rasgos con valor para el diagnóstico taxonómico. También se ha realizado el análisis de alometrías de las distintas estructuras del oído en la subfamilia Homininae y se han propuesto rasgos con valor filogenético. Por otra parte, se han establecido los valores de transmisión de la potencia sonora y del ancho de banda ocupado en G. gorilla, lo que supone los primeros datos conocidos sobre los patrones auditivos de esta especie. Se han calculado dichos parámetros en seis nuevos ejemplares de SH, para caracterizar con más precisión los patrones auditivos de esta población. Además, se ha relacionado la longitud del ancho de banda ocupado con los cambios en las proporciones de las diferentes estructuras del OEM en la subfamilia Homininae y se ha propuesto un modelo sobre la secuencia de cambios del OEM en la evolución de la subfamilia. Finalmente, se ha contrastado la hipótesis según la cual el valor de la longitud del ancho de banda ocupado de una especie está directamente relacionado con su complejidad social y con el número y diversidad de sus vocalizaciones

The Neandertal nature of the Atapuerca Sima de los Huesos mandibles

The recovery of additional mandibular fossils from the Atapuerca Sima de los Huesos (SH) site provides new insights into the evolutionary significance of this sample. In particular, morphological descriptions of the new adult specimens are provided, along with standardized metric data and phylogenetically relevant morphological features for the expanded adult sample. The new and more complete specimens extend the known range of variation in the Atapuerca (SH) mandibles in some metric and morphological details. In other aspects, the addition of new specimens has made it possible to confirm previous observations based on more limited evidence. Pairwise comparisons of individual metric variables revealed the only significant difference between the Atapuerca (SH) hominins and Neandertals was a more vertical symphysis in the latter. Similarly, principal components analysis of size-adjusted variables showed a strong similarity between the Atapuerca (SH) hominins and Neandertals. Morphologically, the Atapuerca (SH) mandibles show nearly the full complement of Neandertal-derived features. Nevertheless, the Neandertals differ from the Atapuerca (SH) mandibles in showing a high frequency of the H/O mandibular foramen, a truncated, thinned and inverted gonial margin, a high placement of the mylohyoid line at the level of the M3, a more vertical symphysis and somewhat more pronounced expression of the chin structures. Size-related morphological variation in the SH hominins includes larger retromolar spaces, more posterior placement of the lateral corpus structures, and stronger markings associated with the muscles of mastication in larger specimens. However, phylogenetically relevant features in the SH sample are fairly stable and do not vary with the overall size of the mandible. Direct comparison of the enlarged mandibular sample from Atapuerca (SH) with the Mauer mandible, the type specimen of H. heidelbergensis, reveals important differences from the SH hominins, and there is no morphological counterpart of Mauer within the SH sample, suggesting the SH fossils should not be assigned to this taxon. The Atapuerca (SH) mandibles show a greater number of derived Neandertal features, particularly those related to midfacial prognathism and in the configuration of the superior ramus, than other European middle Pleistocene specimens. This suggests that more than one evolutionary lineage co-existed in the middle Pleistocene, and, broadly speaking, it appears possible to separate the European middle Pleistocene mandibular remains into two distinct groupings. One group shows a suite of derived Neandertal features and includes specimens from the sites of Atapuerca (SH), Payre, l'Aubesier and Ehringsdorf. The other group includes specimens that generally lack derived Neandertal features and includes the mandibles from the sites of Mauer, Mala Balanica, Montmaurin and (probably) Visogliano. The two published Arago mandibles differ strongly from one another, with Arago 2 probably belonging to this former group, and Neandertal affinities being more difficult to identify in Arago 13. Outside of the SH sample, derived Neandertal features in the mandible only become more common during the second half of the middle Pleistocene. Acceptance of a cladogenetic pattern of evolution during the European middle Pleistocene has the potential to reconcile the predictions of the accretion model and the two phases model for the appearance of Neandertal morphology. The precise taxonomic classification of the SH hominins must contemplate features from the dentition, cranium, mandible and postcranial skeleton, all of which are preserved at the SH site. Nevertheless, the origin of the Neandertal clade may be tied to a speciation event reflected in the appearance of a suite of derived Neandertal features in the face, dentition and mandible, all of which are present in the Atapuerca (SH) hominins. This same suite of features also provides a useful anatomical basis to include other European middle Pleistocene mandibles and crania within the Neandertal clade.Depto. de Geodinámica, Estratigrafía y PaleontologíaFac. de Ciencias GeológicasTRUEBinghamton UniversityMinisterio de Ciencia e Innovación y UniversidadesJunta de Castilla y Leónpu

Cueva de los Torrejones revisited. New insights on the paleoecology of inland Iberia during the Late Pleistocene

34 p.The interior of the Iberian Peninsula has orographic conditions that make this territory especially vulnerable to Quaternary climate oscillations and which actually could have made it decisive for Paleolithic human populations at critical points. For this reason, the information provided by paleontological sites is important for reconstructing climatic and environmental conditions during the Late Pleistocene and understanding how they influenced the species that inhabited them, including humans. Nevertheless, the archaeo-paleontological record is scarce in central Iberia for the Late Pleistocene. A central Iberian site that is key to addressing this issue is Cueva de los Torrejones, which was discovered and excavated during the nineties. Clues indicating the presence of Neandertal populations near the cave site were announced during prior field excavations, including Neandertal remains, Middle Paleolithic artifacts, and evidence of anthropic exploitation of faunal resources at the site. Here we report the new results from the recent excavations and research, including detailed studies on stratigraphy, micromorphology, macro and microvertebrate paleontology, physical and molecular anthropology, taphonomy and zooarchaeology, and analysis of lithic and pottery remains. Our research has led to the detection of three Prehistoric chronologies recorded at the site. The oldest episode corresponds to between MIS 5 and MIS 4 in which the cave was used by carnivores. The second episode is represented by a faunal association dated to 30.0 ka cal BP and is indicative of cooler and more arid environmental conditions and, therefore, compatible with the worsening climate detected previously for MIS 3 in this area. The last episode corresponds to the Chalcolithic, directly dated to ~5000 cal BP in which humans used the cavity for funerary purposes. The DNA analysis of the human remain was assigned to mtDNA haplogroup K, which was originated in the Near East and reached western Europe through the Neolithic expansion. Human occupation during the Paleolithic has been ruled out, including Paleolithic human remains and any kind of anthropic intervention on the Hermann’s tortoise and leopard as was previously proposed at the site.European Research CouncilJunta de Comunidades de Castilla la ManchaMinisterio de Ciencia e InnovaciónCentro Nacional de Investigación sobre la Evolución Humana (CENIEH

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Geometric morphometric analysis of the bony labyrinth of the Sima de los Huesos hominins

The bony labyrinth contains phylogenetic information that can be used to determine interspecific differences between fossil hominins. The present study conducted a comparative 3D geometric morphometric analysis on the bony labyrinth of the Middle Pleistocene Sima de los Huesos (SH) hominins. The findings of this study corroborate previous multivariate analyses of the SH hominin bony labyrinth. The analysis of the semicircular canals revealed the SH hominin canal morphologies appear closer to those of the Neandertals than to those of Homo sapiens. This is attributable to a Neandertal-like ovoid anterior canal, and mediolaterally expanded, circular posterior canal. However, the SH hominins lack the increased torsion in the anterior canal and the inferior orientation of the lateral canal seen in Neandertals. The results of the cochlear analysis indicated that, although there is some overlap, there are notable differences between the SH hominins and the Neandertals. In particular, the SH hominin cochlea appears more constricted than in Neandertals in the first and second turns. A principal component analysis of the full bony labyrinth separated most SH hominins from the Neandertals, which largely clustered with modern humans. A covariance ratio analysis found a significant degree of modularity within the bony labyrinth of all three groups, with the SH hominins and Neandertals displaying the highest modularity. This modular signal in the bony labyrinth may be attributable to different selective pressures related to locomotion and audition. Overall, the results of this study confirm previous suggestions that the semicircular canals in the SH hominins are somewhat derived toward Neandertals, while their cochlea is largely primitive within the genus Homo

The cochlea of the Aroeira 3 Middle Pleistocene cranium—a comparative study

info:eu-repo/semantics/publishedVersio

The bony labyrinth in the Aroeira 3 Middle Pleistocene cranium

The discovery of a partial cranium at the site of Aroeira (Portugal) dating to 389–436 ka augments the current sample of Middle Pleistocene European crania and makes this specimen penecontemporaneous with the fossils from the geographically close Atapuerca Sima de los Huesos (SH) and Arago sites. A recent study of the cranium documented a unique combination of primitive and derived features. The Aroeira 3 cranium preserves the right temporal bone, including the petrosal portion. Virtual reconstruction of the bony labyrinth from μCT scans provides an opportunity to examine its morphology. A series of standard linear and angular measures of the semicircular canals and cochlea in Aroeira 3 were compared with other fossil hominins and recent humans. Our analysis has revealed the absence of derived Neandertal features in Aroeira 3. In particular, the specimen lacks both the derived canal proportions and the low position of the posterior canal, two of the most diagnostic features of the Neandertal bony labyrinth, and Aroeira 3 is more primitive in these features than the Atapuerca (SH) sample. One potentially derived feature (low shape index of the cochlear basal turn) is shared between Aroeira 3 and the Atapuerca (SH) hominins, but is absent in Neandertals. The results of our study provide new insights into Middle Pleistocene population dynamics close to the origin of the Neandertal clade. In particular, the contrasting inner ear morphology between Aroeira 3 and the Atapuerca (SH) hominins suggests a degree of demographic isolation, despite the close geographic proximity and similar age of these two sites

The cochlea of the Sima de los Huesos hominins (Sierra de Atapuerca, Spain): New insights into cochlear evolution in the genus Homo

The cochlea contains taxonomic and phylogenetic information and its morphology is related with hearing abilities among fossil hominins. Data for the genus Homo is presently limited to early Homo and the early Neandertals from Krapina. The present study of the middle Pleistocene hominins from the Sima de los Huesos (SH) provides new evidence on cochlear evolution in the genus Homo. We compared the absolute length, proportional lengths of each turn, number of turns, size and shape of the cross-section of the basal turn, volume, curvature gradient, and thickness of the cochlea between extant Pan troglodytes, extant Homo sapiens, Homo neanderthalensis and the SH hominins. The SH hominins resemble P. troglodytes in the proportionally long basal turn, the small size and round shape of the cross-section of the basal turn, the small cochlear volume and the low cochlear thickness. The SH hominins resemble Neandertals and H. sapiens in their long cochlear length and in the proportionally short third turn. Homo neanderthalensis and H. sapiens share several features, not present in the SH hominins, and that likely represent homoplasies: a larger volume, larger size and oval shape of the cross-section of the basal turn and higher cochlear thickness. Later Neandertals show a derived proportionally shorter apical turn. Changes in cochlear volume in Homo cannot be fully explained by variation in body mass or cochlear length but are more directly related to changes in the cross-sectional area of the basal turn. Based on previous studies of the outer and middle ear in SH hominins, changes in the outer and middle ear preceded changes in the inner ear, and the cochlea and semicircular canals seem to have evolved independently in the Neandertal clade. Finally, the small cochlear volume in the SH hominins suggests a slightly higher upper limit of hearing compared with modern humans

Neanderthals and Homo sapiens had similar auditory and speech capacities

The study of audition in fossil hominins is of great interest given its relationship with intraspecific vocal communication. While the auditory capacities have been studied in early hominins and in the Middle Pleistocene Sima de los Huesos hominins, less is known about the hearing abilities of the Neanderthals. Here, we provide a detailed approach to their auditory capacities. Relying on computerized tomography scans and a comprehensive model from the field of auditory bioengineering, we have established sound power transmission through the outer and middle ear and calculated the occupied bandwidth in Neanderthals. The occupied bandwidth is directly related to the efficiency of the vocal communication system of a species. Our results show that the occupied bandwidth of Neanderthals was greater than the Sima de los Huesos hominins and similar to extant humans, implying that Neanderthals evolved the auditory capacities to support a vocal communication system as efficient as modern human speech