77 research outputs found
Diversification trajectories and paleobiogeography of Neogene chondrichthyans from Europe
Despite the rich fossil record of Neogene chondrichthyans (chimaeras, sharks, rays, and skates) from Europe, little is known about the macroevolutionary processes that generated their current diversity and geographical distribution. We compiled 4368 Neogene occurrences comprising 102 genera, 41 families, and 12 orders from four European regions (Atlantic, Mediterranean, North Sea, and Paratethys) and evaluated their diversification trajectories and paleobiogeographic patterns. In all regions analyzed, we found that generic richness increased during the early Miocene, then decreased sharply during the middle Miocene in the Paratethys, and moderately during the late Miocene and Pliocene in the Mediterranean and North Seas. Origination rates display the most significant pulses in the early Miocene in all regions. Extinction rate pulses varied across regions, with the Paratethys displaying the most significant pulses during the late Miocene and the Mediterranean and North Seas during the late Miocene and early Pliocene. Overall, up to 27% and 56% of the European Neogene genera are now globally and regionally extinct, respectively. The observed pulses of origination and extinction in the different regions coincide with warming and cooling events that occurred during the Neogene globally and regionally. Our study reveals complex diversity dynamics of Neogene chondrichthyans from Europe and their distinct biogeographic composition despite the multiple marine passages that connected the different marine regions during this time
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The origin and correlated evolution of symbiosis and coloniality in Scleractinian corals
Symbiosis and coloniality are ecologically important traits for corals of the order Scleractinia. Symbiotic (zooxanthellate) species are highly successful in shallow waters of tropical and subtropical seas and most of them are colonial. On the other hand, azooxanthellate species present wide distribution ranges and expand to the deep-sea at more than 6,000 m depth. These are mostly solitary, with only few species colonial that form extensive deep reefs. Each ecologically distinctive group encompasses half of the biodiversity of the order and they are not grouped into differentiated monophyletic clades. Paleontologists and evolutionary biologists have debated for decades whether modern scleractinian corals have evolved from symbiotic or colonial ancestors and how these traits have evolved and being involved in the diversification process in corals. Previous comparative analyses throw evidence in favor of coevolution of these characters and toward repetitive loss of symbiosis and coloniality. Nevertheless, the discovery of the origin of the group deep in the Paleozoic, with a deep divergent clade composed of only azooxanthellate corals has questioned these findings. With this work, we disentangle the patterns in the evolution of symbiosis and coloniality, testing if they are correlated and if they follow a gradual or episodic mode of evolution. To this end, we first produce the most complete time-calibrated phylogenetic tree for the order Scleractinia, including new sequences of never-before sampled species and genera. These novel sequences contribute to alleviate the current molecular under sampling of azooxanthellate species. Incorporating phylogenetic uncertainty, we obtained strong evidence in favor of a correlated and episodic model of evolution. This model led to the inference of an azooxanthellate and solitary most recent ancestor of scleractinians. Transition rates between the four different combinations of the two traits showed that while coloniality is gained and lost multiple times, symbiosis first appears around 282 Ma and is never lost. Also, coloniality seems to have appeared before symbiosis in azooxanthellate lineages. Thus, azooxanthellate corals, and especially colonial lineages, have been acting as a source of biodiversity for shallow zooxanthellate coral communities, highlighting the uniqueness of shallow and deep species and the need to preserve them
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Deep-sea origin and depth colonization associated with phenotypic innovations in scleractinian corals
The deep sea (>200 m) is home to a surprisingly rich biota, which in some cases compares to that found in shallow areas. Scleractinian corals are an example of this - they are key species in both shallow and deep ecosystems. However, what evolutionary processes resulted in current depth distribution of the marine fauna is a long-standing question. Various conflicting hypotheses have been proposed, but few formal tests have been conducted. Here, we use global spatial distribution data to test the bathymetric origin and colonization trends across the depth gradient in scleractinian corals. Using a phylogenetic approach, we infer the origin and historical trends in directionality and speed of colonization during the diversification in depth. We also examine how the emergence of photo-symbiosis and coloniality, scleractinian corals' most conspicuous phenotypic innovations, have influenced this process. Our results strongly support an offshore-onshore pattern of evolution and varying dispersion capacities along depth associated with trait-defined lineages. These results highlight the relevance of the evolutionary processes occurring at different depths to explain the origin of extant marine biodiversity and the consequences of altering these processes by human impact, highlighting the need to include this overlooked evolutionary history in conservation plans
Neogene Bony Fishes from the Bahía Inglesa Formation, Northern Chile
Despite being one of the richest Neogene deposits of marine fossil vertebrates along the Pacific coast of South America, no detailed study of bony fishes from the Bahía Inglesa Formation has been carried out. Through the revision of historical collections of the Caldera Paleontological Museum, we describe 27 fossil remains of bony fishes. Fossils described here are distributed in 13 taxa. Among these, Sardinops sp. cf. S. sagax (Clupeidae) represents the first fossil record of the genus for Chile, Labrodon sp. (Labridae) and Stelliferinae (Sciaenidae) are the first respective records for the southeast Pacific Ocean, Sarda sp. (Scombridae) represents the first fossil record for South America, Semicossyphus sp. (Labridae) and Anisotremus sp. (Haemulidae) are the first respective records for the Southern Hemisphere. Gymnosarda sp. (Scombridae) is described for the first time for the Neogene. We performed a paleobathymetric analysis of fossil fishes, including elasmobranchs, to understand the paleoenvironment followed by a similarity analysis that compares the faunal composition of the Bahía Inglesa Fm. with other fossil assemblages for the Pacific of South America. Our results show that the fish fauna from the Bahía Inglesa Fm. likely represents a depth range of 98 to 382 m with a mean depth range of 252 m in an uppermost bathyal environment. The assemblage from the Bahía Inglesa Fm. shows low taxonomic similarity levels with other Neogene geological units from the southeast Pacific Ocean. The study represents the first paleoecological and paleobiogeographic analysis of the fossil fish fauna from the Southeast Pacific.
Key words. Atacama region. Clupeiformes. Eastern Pacific. Paleoenviroments. Perciformes. Ophidiiformes
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Historical warming consistently decreased size, dispersal and speciation rate of fish
There is ongoing debate as to whether fish body size will decrease with global warming and how these changes may impact dispersal ability and speciation rate. Theory predicts that, under warmer temperatures, fish grow to a smaller size, undergo a reduction in dispersal ability and increase speciation rates. However, evaluations of such predictions are hampered owing to the lack of empirical data spanning both wide temporal and geographical scales. Here, using phylogenetic methods, we show that smaller clupeiform fish (anchovies and herrings) occurred historically in warmer waters, moved the shortest distances at low speed and displayed the lowest speciation rates. Furthermore, fish moved faster and evolved rapidly under higher rates of temperature change but these historical rates are far lower than current warming rates. Our results predict a future where smaller clupeiform fish that have reduced ability to move will be more prevalent; this, in turn, may reduce future speciation
Desde el pacífico a la foresta tropical: redes de interacción social en el desierto de atacama durante el pleistoceno final
The social groups that initially inhabited the hyper arid core of the Atacama Desert of northern Chile during the late Pleistocene integrated a wide range of local, regional and supra regional goods and ideas for their social reproduction as suggested by the archaeological evidence contained in several open camps in Pampa del Tamarugal (PdT). Local resources for maintaining their every-day life, included stone raw material, wood, plant and animal fibers, game, and fresh water acquired within a radius of ∼30 km (ca. 1-2 days journey). At a regional scale, some goods were introduced from the Pacific coast (60-80 km to the west, ca. 3-4 days journey), including elongated rounded cobbles used as hammer stones in lithic production, and shells, especially from non-edible species of mollusks. From the Andes (ranging 80-150 km to the east, ca. 5-8 days of journey), they obtained camelid fiber, obsidian and a high-quality chalcedony, in addition to sharing knowledge on projectile point designs (Patapatane and Tuina type forms). Pieces of wood of a tropical forest tree species (Ceiba spp.) from the east Andean lowlands (600 km away, ca. 30 days of journey) were also brought to the PdT. While local goods were procured by the circulation of people within the PdT, the small number of foreign items would have been acquired through some sort of exchange networks that integrated dispersed local communities throughout several ecosystems. These networks may have been a key factor behind the success exhibited by these early huntergatherers in the hyper arid ecosystems of the Atacama Desert at the end of the Pleistocene. Different lines of archaeological evidence including open camps, workshop-quarries, lithic artifacts, archaeofaunal remains, plant and animal fibers and textiles, archaeobotanical remains, and paleoecological data show that people of the PdT managed a wide range of cultural items from the Pacific coast, the Andean highland and the tropical forest, that were integrated with resources gathered locally within the socio-cultural systems established by the end of the Pleistocene. These results are interpreted as material expressions of multi-scalar networking for resource management and other social material and immaterial requirements, which in other words, means that these people were actively connected to regional (coastal and highland), and supra-regional (trans-Andean) exchange networks from and out of the PdT.Los grupos sociales que inicialmente habitaban el núcleo hiperárido del Desierto de Atacama en el norte de Chile durante el Pleistoceno tardío integraron una amplia gama de bienes e ideas, locales, regionales y supra regionales, para su reproducción social, como lo sugieren las evidencias arqueológicas materiales recuperadas en varios campamentos al aire libre en Pampa del Tamarugal (PdT). Los recursos locales para mantener su vida diaria, incluían materias primas líticas, fibras de plantas y animales, presas de caza y agua dulce adquiridos en un radio de ̴30 km (ca. 1-2 días de viaje). A escala regional, se introdujeron algunos elementos desde la costa del Pacífico (60-80 km hacia el oeste, ca. 3 a 4 días de viaje), incluidos rodados redondeados alargados, utilizados como percutores en la producción lítica y conchas, especialmente de especies no comestibles de moluscos. Desde los Andes (80-150 km al este, ca. 5-8 días de viaje), obtuvieron fibra de camélido, obsidiana y una calcedonia de alta calidad, además de compartir conocimientos sobre diseños de puntas de proyectil (tipo Patapatane y Tuina). También se llevaron a la PdT trozos de madera de una especie de árbol de los bosques tropicales (Ceiba spp.) de las tierras bajas al este de los Andes (600 km de distancia, ca. 30 días de viaje). Mientras que los bienes locales fueron adquiridos por la circulación de personas dentro de la PdT, el pequeño número de artículos foráneos se adquirieron a través de redes de intercambio que integraron comunidades locales dispersas en varios ecosistemas; lo que debió ser un factor clave detrás del éxito demostrado por estos primeros cazadores-recolectores en los ecosistemas hiperáridos del Desierto de Atacama hacia el final del Pleistoceno. Diferentes líneas de evidencia arqueológica que incluyen campamentos al aire libre, talleres, canteras, artefactos líticos, restos arqueofaunales, fibras y textiles de plantas y animales, restos arqueobotánicos y datos paleoecológicos, muestran que la gente de la PdT manejaron una amplia gama de elementos culturales desde la costa del Pacífico, el altiplano andino y el bosque tropical, que se integraron a los recursos recolectados localmente dentro de los sistemas socioculturales establecidos al final del Pleistoceno. Estos resultados se interpretan como una expresión material de una red de múltiples escalas para la gestión de recursos y otros requisitos sociales e inmateriales, lo que en otras palabras, significaría que estos grupos sociales estaban conectados activamente con redes de interacción regionales (costa y tierras altas) y supra-regionales (transandinas) desde y hacia la PdT.Fil: Santoro, Calógero M.. Universidad de Tarapaca.; ChileFil: Gayo, Eugenia M.. Centro de Ciencia del Clima y la Resiliencia; Chile. Universidad de Concepción; ChileFil: Capriles Flores, Jose Mariano. State University of Pennsylvania; Estados UnidosFil: Rivadeneira Valenzuela, Marcelo Michel. Comisión Nacional de Investigación Científica y Tecnológica. Centro de Investigación Regional. Centro de Estudios en Zonas Áridas; Chile. Universidad Católica del Norte; Chile. Universidad de La Serena; ChileFil: Herrera, Katherine A.. Universite Paris Ouest Nanterre la Defense; Francia. Universidad de Tarapaca.; ChileFil: Mandakovic, Valentina. No especifíca;Fil: Rallo, Mónica. No especifíca;Fil: Rech, Jason A.. University of Miami; Estados UnidosFil: Cases, Bárbara. Universidad de Tarapaca.; ChileFil: Briones, Luis. Museo Municipalidad de Pica; ChileFil: Olguín, Laura. Universidad Católica del Norte, San Pedro de Atacama; ChileFil: Valenzuela, Daniela. Universidad de Tarapaca.; ChileFil: Borrero, Luis Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Multidisciplinario de Historia y Ciencias Humanas; ArgentinaFil: Ugalde, Paula C.. University of Arizona; Estados Unidos. Universidad de Tarapaca.; ChileFil: Rothhammer, Francisco. Universidad de Tarapaca.; ChileFil: Latorre, Claudio. Pontificia Universidad Católica de Chile; Chile. Instituto de Ecología y Biodiversidad; ChileFil: Szpak, Paul. Trent University; Canad
¿Qué sabemos de los peces óseos marinos del neógeno en Chile? Diversidad e implicaciones biogeográficas
Durante el Neógeno ocurren intensos eventos, oceanográficos y climáticos, que influyeron sobre la fauna marina de Chile desde el pasado hasta la actualidad. Estudios enfocados en la evaluación del efecto de estos eventos sobre la diversidad de mamíferos, aves y tiburones han sido previamente abordados. Sin embargo, las interacciones de estos eventos con los peces óseos como grupo de estudio no han sido analizados en detalle. Este trabajo compara la diversidad de peces óseos del Neógeno con la actualidad y da a conocer lo que sabemos de su diversidad. Se procesaron los datos disponibles de la presencia de peces óseos marinos en formaciones neógenas de Chile y la actualidad. Se comparó la composición del registro fósil de peces neógenos con el registro de peces actuales a 3 niveles taxonómicos distintos (familia, género y especie). Finalmente, se analizaron los rangos de distribución de los taxa fósiles que sobrevivieron con el objetivo de realizar aproximaciones de las dinámicas paleobiogeográficas. Nuestros resultados muestran que la diversidad actual de peces óseos marinos en Chile es de 624 géneros (1.196 especies), mientras que para el Neógeno se han reportado 65 géneros (46 especies). Comparado con la diversidad actual, el registro fósil de peces es representado por un 3,9% a nivel de especie, 10,4% a nivel de género y 23,4% a nivel de familias, lo que puede ser relacionado con la baja cantidad de estudios enfocados en fósiles de este grupo. Del total de 46 especies fósiles reportadas, sólo una se encuentra actualmente presente en las costas de Chile. A nivel genérico, un 38,5% se encuentra actualmente ausente en la región y un 61,5% sobrevive. En relación a los géneros ausentes actualmente, un 20% corresponde a extinción global y un 80% a extinción regional. Estos cambios en las dinámicas biogeográficas de peces óseos del pasado al reciente, podrían estar relacionadas con los intensos eventos climáticos y oceanográficos que han ocurrido en los últimos 23 millones de años. Los análisis de rarefacción y de extrapolación de especies confirman que a pesar de que han aumentado los trabajos sobre peces óseos en los últimos años, todavía se podrían encontrar un mayor número de taxa si se aplica un mayor esfuerzo de muestreo. Estudios futuros podrían ayudarnos a comprender de mejor manera el efecto de los cambios climáticos y oceanográficos sobre los peces del Neógeno de Chile.Durant el Neogen ocorren intensos esdeveniments, oceanogràfics, i climàtics, que van influir sobre la fauna marina de Xile des del passat fins a l’actualitat. Estudis enfocats en l’avaluació de l’efecte d’aquests esdeveniments sobre la diversitat de mamífers, ocells i taurons han sigut prèviament abordats. No obstant això, les interaccions d’aquests esdeveniments amb els peixos ossis com a grup d’estudi no han sigut analitzats detalladament. Aquest treball analitza la diversitat de peixos ossis del Neogen comparat amb l’actualitat i dona a conéixer que sabem de la seua diversitat. Es van analizar les dades disponibles de la presència de peixos ossis marins en formacions neógenas de Xile i l’actualitat. Es va comparar la composició del registre fòssil de peixos neògens amb el registre de peixos actuals a 3 nivells taxonòmics diferents (família, gènere i espècie). Finalment, es van analizar els rangs de distribució dels taxa fòssils que van sobreviure amb la finalitat de realitzar aproximacions de les dinàmiques paleobiogeográficas. Els nostres resultats mostren que la diversitat actual de peixos ossis marins a Xile és de 624 gèneres (1.196 espècies), mentre que per al Neogen s’han reportat 65 gèneres (46 espècies). Comparat amb la diversitat actual, el registre fòssil de peixos és representat per un 3,9% a nivell d’espècie, 10,4% a nivell de gènere i 23,4% a nivell de famílies, la qual cosa pot ser relacionat amb la baixa quantitat d’estudis enfocats en fòssils d’aquest grup. Del total de 46 espècies fòssils reportades, només un 4% es troba actualment present en les costes de Xile. A nivell genèric, un 38.5% es troba actualment absent a la regió i un 61.5% sobreviu. En relació als gèneres absents actualment, un 20% correspon a extinció global i un 80% a extinció regional. Aquests canvis en les dinàmiques biogeogràfiques de peixos ossis del passat al recent, podrien estar relacionades amb els intensos esdeveniments climàtics i oceanogràfics que han ocorregut en els últims 23 milions d’anys. Les anàlisis de rarefacció i d’extrapolació d’espècies confirmen que a pesar que han augmentat els treballs sobre el grup en els últims anys, encara es podrien trobar un major número de taxa si s’aplica un major esforç de mostreig. Estudis futurs podrien ajudar-nos a comprendre de millor manera l’efecte dels canvis climàtics i oceanogràfics sobre els peixos del Neogen de Xile.During the Neogene occurred intense oceanographic and climatic events which had an effect on the marine fauna from the past to the present. Studies focused on the evaluation of the effect of these events on the diversity of mammals, birds and sharks have been previously addressed. However, the interactions of these events with bony fishes as a study group have not been analyzed in detail. This work analyzes the diversity of bony fishes from the Neogene compared to today and reveals what we know about their diversity. We analyzed the available data on the presence of marine bony fishes from Neogene formations in Chile and today. The composition of the fossil record of Neogene fishes was compared to the current fish record at 3 different taxonomic levels (family, genus, and species). Lastly, the distribution ranges of the surviving fossil taxa were analyzed in order to make approximations of the paleobiogeographic dynamics. Our results show that the current diversity of marine bony fish in Chile is composed of 624 genera (1,196 species), whereas from the Neogene 65 genera (46 species) have been reported. Compared to the current diversity, the fossil record of fishes is represented by 3.9% at the species level, 10.4% at the genus level and 23.4% at the family level, which can be related to the low number of studies focused on fossils of this group. Of the total of 46 fossil species reported, only 4% is currently present along the coast of Chile. At a generic level, 38.5% are currently absent in the region whereas 61.5% survived. In relation to the genera currently absent in the region, 20% are globally extinct and 80% regional extinct. These changes in the biogeographic dynamics of bony fishes from the past to the recent could be related to the intense climatic and oceanographic events that have occurred in the last 23 million years. The rarefaction and extrapolation analyses confirm that although the studies focused on the group have increased in the last years, a higher number of taxa could still be found if the sampling effort is increased. Future studies could help us to a better understanding of the effects of climatic and oceanographic changes on the group during the Neogene of Chile
Immunostaining with D2–40 improves evaluation of lymphovascular invasion, but may not predict sentinel lymph node status in early breast cancer
<p>Abstract</p> <p>Background</p> <p>Sentinel lymph node (SLN) biopsy is a widely used diagnostic procedure in the management of early breast cancer. When SLN is free of metastasis, complete axillary dissection may be skipped for staging in clinically N0 patients, allowing a more conservative procedure. Histological tumor features that could reliably predict SLN status have not yet been established. Since the degree of tumor lymphangiogenesis and vascularization may theoretically be related to the risk of lymph node metastasis, we sought to evaluate the relationship between lymph vessel invasion (LVI), lymphatic microvascular density (LVD), microvascular density (MVD) and VEGF-A expression, with SLN status and other known adverse clinical risk factors.</p> <p>Methods</p> <p>Protein expression of D2–40, CD34, and VEGF-A was assessed by immunohistochemistry on paraffin-embedded sections of primary breast cancer specimens from 92 patients submitted to SLN investigation. The presence of LVI, the highest number of micro vessels stained for D2–40 and CD34, and the protein expression of VEGF-A were compared to SLN status, clinicopathological features and risk groups.</p> <p>Results</p> <p>LVI was detected in higher ratios by immunostaining with D2–40 (p < 0.0001), what would have changed the risk category from low to intermediate in four cases (4.3%). There was no association between LVI and other angiogenic parameters determined by immunohistochemistry with SLN macrometastases, clinical features or risk categories.</p> <p>Conclusion</p> <p>Assessment of LVI in breast carcinoma may be significantly increased by immunostaining with D2–40, but the clinical relevance of altering the risk category using this parameter may not be advocated according to our results, neither can the use of LVI and LVD as predictors of SLN macrometastasis in early breast cancer.</p
Meta-analysis of 49 549 individuals imputed with the 1000 Genomes Project reveals an exonic damaging variant in ANGPTL4 determining fasting TG levels
So far, more than 170 loci have been associated with circulating lipid levels through genome-wide association studies (GWAS). These associations are largely driven by common variants, their function is often not known, and many are likely to be markers for the causal variants. In this study we aimed to identify more new rare and low-frequency functional variants associated with circulating lipid levels
Salud de los trabajadores
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