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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
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
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
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
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
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
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
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
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
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)
Aaron O'Dea, Harilaos A Lessios, Anthony G Coates, Ron I Eytan, Sergio A Restrepo-Moreno, Alberto L Cione, Laurel S Collins, Alan de Queiroz, David W Farris, Richard D Norris, Robert F Stallard, Michael O Woodburne, Orangel Aguilera, Marie-Pierre Aubry, William A Berggren, Ann F Budd, Mario A Cozzuol, Simon E Coppard, Herman Duque-Caro, Seth Finnegan, Germán M Gasparini, Ethan L Grossman, Kenneth G Johnson, Lloyd D Keigwin, Nancy Knowlton, Egbert G Leigh, Jill S Leonard-Pingel, Peter B Marko, Nicholas D Pyenson, Paola G Rachello-Dolmen, Esteban Soibelzon, Leopoldo Soibelzon, Jonathan A Todd, Geerat J Vermeij, Jeremy B C Jackson
The formation of the Isthmus of Panama stands as one of the greatest natural events of the Cenozoic, driving profound biotic transformations on land and in the oceans. Some recent studies suggest that the Isthmus formed many millions of years earlier than the widely recognized age of approximately 3 million years ago (Ma), a result that if true would revolutionize our understanding of environmental, ecological, and evolutionary change across the Americas. To bring clarity to the question of when the Isthmus of Panama formed, we provide an exhaustive review and reanalysis of geological, paleontological, and molecular records...
August 2016: Science Advances
S J Salayeva, J M Ojaghi, A N Pashayeva, V I Izzatullayeva, E M Akhundova, Z I Akperov
To examine the genetic diversity of Vitis vinifera L., growing in the Republic of Azerbaijan in the region near the Caspian Sea, nuclear genomes of 31 cultivated and 34 wild grapevine accessions were studied at population and individual levels using five ISSR primers. In total, 51 fragments were amplified, of which 45 were found to be polymorphic. A high level of polymorphism was revealed (the mean PPF and PIC values constituted 87.69% and 0.94, respectively). High values of the EMR, MI, and RP indices showed the effectiveness of the application of ISSR primers and the possibility of their use in further investigations in this direction...
April 2016: Genetika
Toni Lyn Morelli, Christopher Daly, Solomon Z Dobrowski, Deanna M Dulen, Joseph L Ebersole, Stephen T Jackson, Jessica D Lundquist, Constance I Millar, Sean P Maher, William B Monahan, Koren R Nydick, Kelly T Redmond, Sarah C Sawyer, Sarah Stock, Steven R Beissinger
Refugia have long been studied from paleontological and biogeographical perspectives to understand how populations persisted during past periods of unfavorable climate. Recently, researchers have applied the idea to contemporary landscapes to identify climate change refugia, here defined as areas relatively buffered from contemporary climate change over time that enable persistence of valued physical, ecological, and socio-cultural resources. We differentiate historical and contemporary views, and characterize physical and ecological processes that create and maintain climate change refugia...
2016: PloS One
P Raia, F Carotenuto, A Mondanaro, S Castiglione, F Passaro, F Saggese, M Melchionna, C Serio, L Alessio, D Silvestro, M Fortelius
Animal clades tend to follow a predictable path of waxing and waning during their existence, regardless of their total species richness or geographic coverage. Clades begin small and undifferentiated, then expand to a peak in diversity and range, only to shift into a rarely broken decline towards extinction. While this trajectory is now well documented and broadly recognised, the reasons underlying it remain obscure. In particular, it is unknown why clade extinction is universal and occurs with such surprising regularity...
2016: Scientific Reports
Noritaka Adachi, Molly Robinson, Aden Goolsbee, Neil H Shubin
The diversification of paired appendages has been a major factor in the evolutionary radiation of vertebrates. Despite its importance, an understanding of the origin of paired appendages has remained elusive. To address this problem, we focused on T-box transcription factor 5 (Tbx5), a gene indispensable for pectoral appendage initiation and development. Comparison of gene expression in jawless and jawed vertebrates reveals that the Tbx5 expression in jawed vertebrates is derived in having an expression domain that extends caudal to the heart and gills...
September 6, 2016: Proceedings of the National Academy of Sciences of the United States of America
P David Polly
No abstract text is available yet for this article.
August 16, 2016: Proceedings of the National Academy of Sciences of the United States of America
Lizzie Wade
No abstract text is available yet for this article.
August 5, 2016: Science
Mauro Valente, Wladimir Molina, Lila Carrizales Silva, Rodolfo Figueroa, Francisco Malano, Pedro Pérez, Mauricio Santibañez, José Vedelago
Fricke solution has a wide range of applications as radiation detector and dosimetry. It is particularly appreciated in terms of relevant comparative advantages, like tissue-equivalence when prepared in aqueous media like gel matrix, continuous mapping capability, independence of dose rate and incident direction, as well as linear dose response. This work presents the development and characterization of an improved Fricke gel system, based on modified chemical compositions, making possible its application in clinical radiology due to its improved sensitivity...
2016: Journal of Applied Clinical Medical Physics
Irina Morozova, Pavel Flegontov, Alexander S Mikheyev, Sergey Bruskin, Hosseinali Asgharian, Petr Ponomarenko, Vladimir Klyuchnikov, GaneshPrasad ArunKumar, Egor Prokhortchouk, Yuriy Gankin, Evgeny Rogaev, Yuri Nikolsky, Ancha Baranova, Eran Elhaik, Tatiana V Tatarinova
The term 'ancient DNA' (aDNA) is coming of age, with over 1,200 hits in the PubMed database, beginning in the early 1980s with the studies of 'molecular paleontology'. Rooted in cloning and limited sequencing of DNA from ancient remains during the pre-PCR era, the field has made incredible progress since the introduction of PCR and next-generation sequencing. Over the last decade, aDNA analysis ushered in a new era in genomics and became the method of choice for reconstructing the history of organisms, their biogeography, and migration routes, with applications in evolutionary biology, population genetics, archaeogenetics, paleo-epidemiology, and many other areas...
August 2016: DNA Research: An International Journal for Rapid Publication of Reports on Genes and Genomes
A Michelle Lawing, P David Polly, Diana K Hews, Emília P Martins
Fossils and other paleontological information can improve phylogenetic comparative method estimates of phenotypic evolution and generate hypotheses related to species diversification. Here, we use fossil information to calibrate ancestral reconstructions of suitable climate for Sceloporus lizards in North America. Integrating data from the fossil record, general circulation models of paleoclimate during the Miocene, climate envelope modeling, and phylogenetic comparative methods provides a geographically and temporally explicit species distribution model of Sceloporus-suitable habitat through time...
August 2016: American Naturalist
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