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https://www.readbyqxmd.com/read/28107398/integrated-chronology-flora-and-faunas-and-paleoecology-of-the-alajuela-formation-late-miocene-of-panama
#1
Bruce J MacFadden, Douglas S Jones, Nathan A Jud, Jorge W Moreno-Bernal, Gary S Morgan, Roger W Portell, Victor J Perez, Sean M Moran, Aaron R Wood
The late Miocene was an important time to understand the geological, climatic, and biotic evolution of the ancient New World tropics and the context for the Great American Biotic Interchange (GABI). Despite this importance, upper Miocene deposits containing diverse faunas and floras and their associated geological context are rare in Central America. We present an integrated study of the geological and paleontological context and age of a new locality from Lago Alajuela in northern Panama (Caribbean side) containing late Miocene marine and terrestrial fossils (plants, invertebrates, and vertebrates) from the Alajuela Formation...
2017: PloS One
https://www.readbyqxmd.com/read/28073604/morphometric-and-genetic-analysis-of-arcella-intermedia-and-arcella-intermedia-laevis-amoebozoa-arcellinida-illuminate-phenotypic-plasticity-in-microbial-eukaryotes
#2
Alfredo L Porfírio-Sousa, Giulia M Ribeiro, Daniel J G Lahr
Testate amoebae are eukaryotic microorganisms characterized by the presence of an external shell (test). The shell morphology is used as a diagnostic character, but discordance between morphological and molecular data has been demonstrated in groups of arcellinids (Amoebozoa), one of the principal groups of testate amoebae. Morphology of the test is supposed to differentiate genera and species and it is applied in ecological, monitoring and paleontological studies. However, if phenotype does not reflect genotype, conclusions in these types of studies become severely impaired...
November 25, 2016: European Journal of Protistology
https://www.readbyqxmd.com/read/28028456/seqenv-linking-sequences-to-environments-through-text-mining
#3
Lucas Sinclair, Umer Z Ijaz, Lars Juhl Jensen, Marco J L Coolen, Cecile Gubry-Rangin, Alica Chroňáková, Anastasis Oulas, Christina Pavloudi, Julia Schnetzer, Aaron Weimann, Ali Ijaz, Alexander Eiler, Christopher Quince, Evangelos Pafilis
Understanding the distribution of taxa and associated traits across different environments is one of the central questions in microbial ecology. High-throughput sequencing (HTS) studies are presently generating huge volumes of data to address this biogeographical topic. However, these studies are often focused on specific environment types or processes leading to the production of individual, unconnected datasets. The large amounts of legacy sequence data with associated metadata that exist can be harnessed to better place the genetic information found in these surveys into a wider environmental context...
2016: PeerJ
https://www.readbyqxmd.com/read/28012461/ten-years-in-the-dump-an-updated-review-of-the-miocene-primate-bearing-localities-from-abocador-de-can-mata-ne-iberian-peninsula
#4
David M Alba, Isaac Casanovas-Vilar, Miguel Garcés, Josep M Robles
More than ten years of paleontological fieldwork during the enlargement of the Can Mata Landfill (Abocador de Can Mata [ACM]), in els Hostalets de Pierola (Vallès-Penedès Basin, NE Iberian Peninsula) led to the recovery of >60,000 Miocene vertebrate remains. The huge sampling effort (due to continuous surveillance of heavy machinery digging activity, coupled with manual excavation and screen-washing of sediments) enabled generally rare faunal elements such as pliopithecoid and hominoid primates to be found...
January 2017: Journal of Human Evolution
https://www.readbyqxmd.com/read/28004894/explanations-for-adaptations-just-so-stories-and-limitations-on-evidence-in-evolutionary-biology
#5
Richard J Smith
Explanations of the historical origin of specific individual traits are a key part of the research program in paleontology and evolutionary biology. Why did bipedalism evolve in the human lineage? Why did some dinosaurs and related species have head crests? Why did viviparity evolve in some reptiles? Why did the common ancestor of primates evolve stereoscopic vision, grasping hands and feet, nails instead of claws, and large brains? These are difficult questions. To varying degrees, an explanation must grapple with (1) judgments about changes in fitness that might follow from a change in morphology - without actually observing behavior or measuring reproductive success, (2) the relationship between genes and traits, (3) limitations on doing relevant experiments, (4) the interpretation of causes that are almost certainly contingent, multifactorial, interactive, hierarchical, nonlinear, emergent, and probabilistic rather than deterministic, (5) limited information about variation and ontogeny, (6) a dataset based on the random fortunes of the historical record, including only partial hard-tissue morphology and no soft-tissue morphology, (7) an equally partial and problematic (for example, time-averaged) record of the environment, (8) the compression of all data into a geological time scale that is likely to miss biologically important events or fluctuations, (9) dependence on a process that can only be inferred ("form and even behavior may leave fossil traces, but forces like natural selection do not", (1:130) ) and finally, (10) the assumption of the "adaptationist programme"(2) that the trait in question is in fact an adaptation rather than a consequence of genetic drift, correlated evolution, pleiotropy, exaptation, or other mechanisms...
November 2016: Evolutionary Anthropology
https://www.readbyqxmd.com/read/28003534/dental-data-perform-relatively-poorly-in-reconstructing-mammal-phylogenies-morphological-partitions-evaluated-with-molecular-benchmarks
#6
Robert S Sansom, Matthew Albion Wills, Tamara Williams
Phylogenetic trees underpin reconstructions of evolutionary history and tests of evolutionary hypotheses. They are inferred from both molecular and morphological data, yet the relative value of morphology has been questioned in this context due to perceived homoplasy, developmental linkage, and non-independence of characters. Nevertheless, fossil data are limited to incomplete subsets of preserved morphology, and different regions are treated as equivalent. Through meta-analysis of 40 datasets, we show here that the dental and osteological characters of mammals convey significantly different phylogenetic signals, and that osteological characters are significantly more compatible with molecular trees...
December 20, 2016: Systematic Biology
https://www.readbyqxmd.com/read/28000409/the-evolution-of-the-zygomatic-bone-from-agnatha-to-tetrapoda
#7
Zhikun Gai, Xiaobo Yu, Min Zhu
Establishing the homology of the zygomatic or jugal bone and tracing its origin and early evolution represents a complex issue because of large morphological gaps between various groups of vertebrates. Using recent paleontological findings, we discuss the deep homology of the zygomatic or jugal bone in stem gnathostomes (placoderms) and examine its homology and modifications in crown gnathostomes (acanthodians, chondrichthyans and osteichthyans). The discovery of the placoderm Entelognathus from the Silurian of China (∼423 million years ago) established that the large dermal plates in placoderms and osteichthyans are homologous...
January 2017: Anatomical Record: Advances in Integrative Anatomy and Evolutionary Biology
https://www.readbyqxmd.com/read/27940618/from-teeth-to-baleen-and-raptorial-to-bulk-filter-feeding-in-mysticete-cetaceans-the-role-of-paleontological-genetic-and-geochemical-data-in-feeding-evolution-and-ecology
#8
Annalisa Berta, Agnese Lanzetti, Eric G Ekdale, Thomas A Deméré
The origin of baleen and filter feeding in mysticete cetaceans occurred sometime between approximately 34 and 24 million years ago and represents a major macroevolutionary shift in cetacean morphology (teeth to baleen) and ecology (raptorial to filter feeding). We explore this dramatic change in feeding strategy by employing a diversity of tools and approaches: morphology, molecules, development, and stable isotopes from the geological record. Adaptations for raptorial feeding in extinct toothed mysticetes provide the phylogenetic context for evaluating morphological apomorphies preserved in the skeletons of stem and crown edentulous mysticetes...
December 2016: Integrative and Comparative Biology
https://www.readbyqxmd.com/read/27939713/incorporating-fossils-into-hypotheses-of-insect-phylogeny
#9
REVIEW
Jessica L Ware, Phillip Barden
Fossils represent stem and crown lineages, and their inclusion in phylogenetic reconstruction influences branch lengths, topology, and divergence time estimation. In addition, paleontological data may inform trends in morphological evolution as well as biogeographic history. Here we review the incorporation of fossils in studies of insect evolution, from morphological analyses to combined 'total evidence' node dating analyses. We discuss challenges associated with fossil based phylogenetics, and suggest best practices for use in tree reconstruction...
December 2016: Current Opinion in Insect Science
https://www.readbyqxmd.com/read/27917244/la-images-a-software-for-elemental-distribution-bioimaging-using-la-icp-ms-data
#10
Hugo López-Fernández, Gustavo de S Pessôa, Marco A Z Arruda, José L Capelo-Martínez, Florentino Fdez-Riverola, Daniel Glez-Peña, Miguel Reboiro-Jato
The spatial distribution of chemical elements in different types of samples is an important field in several research areas such as biology, paleontology or biomedicine, among others. Elemental distribution imaging by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is an effective technique for qualitative and quantitative imaging due to its high spatial resolution and sensitivity. By applying this technique, vast amounts of raw data are generated to obtain high-quality images, essentially making the use of specific LA-ICP-MS imaging software that can process such data absolutely mandatory...
2016: Journal of Cheminformatics
https://www.readbyqxmd.com/read/27897168/stepwise-onset-of-the-icehouse-world-and-its-impact-on-oligo-miocene-central-asian-mammals
#11
Mathias Harzhauser, Gudrun Daxner-Höck, Paloma López-Guerrero, Olivier Maridet, Adriana Oliver, Werner E Piller, Sylvain Richoz, Margarita A Erbajeva, Thomas A Neubauer, Ursula B Göhlich
Central Asia is a key area to study the impact of Cenozoic climate cooling on continental ecosystems. One of the best places to search for rather continuous paleontological records is the Valley of Lakes in Mongolia with its outstandingly fossil-rich Oligocene and Miocene terrestrial sediments. Here, we investigate the response by mammal communities during the early stage of Earth's icehouse climate in Central Asia. Based on statistical analyses of occurrence and abundance data of 18608 specimens representing 175 mammal species and geochemical (carbon isotopes) and geophysical (magnetic susceptibility) data we link shifts in diversities with major climatic variations...
November 29, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27886207/characteristic-tetrapod-musculoskeletal-limb-phenotype-emerged-more-than-400-mya-in-basal-lobe-finned-fishes
#12
Rui Diogo, Peter Johnston, Julia L Molnar, Borja Esteve-Altava
Previous accounts of the origin of tetrapod limbs have postulated a relatively sudden change, after the split between extant lobe-finned fish and tetrapods, from a very simple fin phenotype with only two muscles to the highly complex tetrapod condition. The evolutionary changes that led to the muscular anatomy of tetrapod limbs have therefore remained relatively unexplored. We performed dissections, histological sections, and MRI scans of the closest living relatives of tetrapods: coelacanths and lungfish. Combined with previous comparative, developmental and paleontological information, our findings suggest that the characteristic tetrapod musculoskeletal limb phenotype was already present in the Silurian last common ancestor of extant sarcopterygians, with the exception of the autopod (hand/foot) structures, which have no clear correspondence with fish structures...
November 25, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27804976/tetrapod-limb-and-sarcopterygian-fin-regeneration-share-a-core-genetic-programme
#13
Acacio F Nogueira, Carinne M Costa, Jamily Lorena, Rodrigo N Moreira, Gabriela N Frota-Lima, Carolina Furtado, Mark Robinson, Chris T Amemiya, Sylvain Darnet, Igor Schneider
Salamanders are the only living tetrapods capable of fully regenerating limbs. The discovery of salamander lineage-specific genes (LSGs) expressed during limb regeneration suggests that this capacity is a salamander novelty. Conversely, recent paleontological evidence supports a deeper evolutionary origin, before the occurrence of salamanders in the fossil record. Here we show that lungfishes, the sister group of tetrapods, regenerate their fins through morphological steps equivalent to those seen in salamanders...
November 2, 2016: Nature Communications
https://www.readbyqxmd.com/read/27725256/segmentation-in-tardigrada-and-diversification-of-segmental-patterns-in-panarthropoda
#14
Frank W Smith, Bob Goldstein
The origin and diversification of segmented metazoan body plans has fascinated biologists for over a century. The superphylum Panarthropoda includes three phyla of segmented animals-Euarthropoda, Onychophora, and Tardigrada. This superphylum includes representatives with relatively simple and representatives with relatively complex segmented body plans. At one extreme of this continuum, euarthropods exhibit an incredible diversity of serially homologous segments. Furthermore, distinct tagmosis patterns are exhibited by different classes of euarthropods...
October 7, 2016: Arthropod Structure & Development
https://www.readbyqxmd.com/read/27717134/ontogeny-of-modern-human-longitudinal-body-and-transverse-shoulder-proportions
#15
Mélanie A Frelat, Michael Coquerelle, Erik Trinkaus
OBJECTIVES: Whereas variation of modern human adult body size and shape has been widely studied in the context of ecogeographical clines, little is known about the differential growth patterns of transverse and longitudinal dimensions among human populations. Our study explored the ontogenetic variation of those body proportions in modern humans. METHODS: We compared results from four different approaches to study cross-sectional skeletal samples of Africans (n = 43), Amerindians (n = 69) and Europeans (n = 40) from 0 to 14 years of age...
September 26, 2016: American Journal of Human Biology: the Official Journal of the Human Biology Council
https://www.readbyqxmd.com/read/27700620/earliest-evidence-of-toxocara-in-a-1-2-million-year-old-extinct-hyena-pachycrocuta-brevirostris-coprolite-from-nw-pakistan
#16
Angela Perri, Susann Heinrich, Shira Gur-Arieh, Jeffrey J Saunders
The study of fossil parasites can provide insight into the antiquity of host-parasite relationships and the origins and evolution of these paleoparasites. Here, a coprolite (fossilized feces) from the 1.2-million-year-old paleontological site of Haro River Quarry in northwestern Pakistan was analyzed for paleoparasites. Micromorphological thin sectioning and Fourier-Transform Infrared Spectrometry (FTIR) analysis confirms the coprolite belonged to a bone-eating carnivore, likely the extinct giant short-faced hyena (Pachycrocuta brevirostris)...
October 4, 2016: Journal of Parasitology
https://www.readbyqxmd.com/read/27661065/high-migration-rates-shape-the-postglacial-history-of-amphi-atlantic-bryophytes
#17
Aurélie Désamoré, Jairo Patiño, Patrick Mardulyn, Stuart F Mcdaniel, Florian Zanatta, Benjamin Laenen, Alain Vanderpoorten
Paleontological evidence and current patterns of angiosperm species richness suggest that European biota experienced more severe bottlenecks than North American ones during the last glacial maximum. How well this pattern fits other plant species is less clear. Bryophytes offer a unique opportunity to contrast the impact of the last glacial maximum in North America and Europe because about 60% of the European bryoflora is shared with North America. Here, we use population genetic analyses based on approximate Bayesian computation on eight amphi-Atlantic species to test the hypothesis that North American populations were less impacted by the last glacial maximum, exhibiting higher levels of genetic diversity than European ones and ultimately serving as a refugium for the postglacial recolonization of Europe...
September 23, 2016: Molecular Ecology
https://www.readbyqxmd.com/read/27659724/waking-the-undead-implications-of-a-soft-explosive-model-for-the-timing-of-placental-mammal-diversification
#18
Mark S Springer, Christopher A Emerling, Robert W Meredith, Jan E Janečka, Eduardo Eizirik, William J Murphy
The explosive, long fuse, and short fuse models represent competing hypotheses for the timing of placental mammal diversification. Support for the explosive model, which posits both interordinal and intraordinal diversification after the KPg mass extinction, derives from morphological cladistic studies that place Cretaceous eutherians outside of crown Placentalia. By contrast, most molecular studies favor the long fuse model wherein interordinal cladogenesis occurred in the Cretaceous followed by intraordinal cladogenesis after the KPg boundary...
September 19, 2016: Molecular Phylogenetics and Evolution
https://www.readbyqxmd.com/read/27598842/relationships-of-%C3%A2-codoichthys-carnavalii-santos-1994-teleostei-clupeomorpha-%C3%A2-ellimmichthyiformes-from-the-late-aptian-of-s%C3%A3-o-lu%C3%A3-s-graja%C3%A3%C2%BA-basin-ne-brazil
#19
Francisco J DE Figueiredo, Douglas R M Ribeiro
†Codoichthys carnavalii is a clupeomorph fish only found in calcareous concretions of Codó Formation, State of Maranhão. It is known based on three specimens housed in the paleontological collection of the Museu de Ciências da Terra of Departamento Nacional da Produção Mineral, Rio de Janeiro. It was omitted in most of recent cladistic analyses about clupeomorphs. We revisited its anatomy furnishing new data and additional restorations. Furthermore we explored the relationships of †Codoichthys with the computer program TNT based on a matrix with 30 taxa and 60 unordered and unweight characters...
September 2016: Anais da Academia Brasileira de Ciências
https://www.readbyqxmd.com/read/27572990/emerging-approaches-in-synchrotron-studies-of-materials-from-cultural-and-natural-history-collections
#20
REVIEW
Loïc Bertrand, Sylvain Bernard, Federica Marone, Mathieu Thoury, Ina Reiche, Aurélien Gourrier, Philippe Sciau, Uwe Bergmann
Synchrotrons have provided significant methods and instruments to study ancient materials from cultural and natural heritages. New ways to visualise (surfacic or volumic) morphologies are developed on the basis of elemental, density and refraction contrasts. They now apply to a wide range of materials, from historic artefacts to paleontological specimens. The tunability of synchrotron beams owing to the high flux and high spectral resolution of photon sources is at the origin of the main chemical speciation capabilities of synchrotron-based techniques...
February 2016: Topics in Current Chemistry (Journal)
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