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Université de Fribourg

Disproportionate extinction of South American mammals drove the asymmetry of the Great American Biotic Interchange

Carrillo, Juan D. ; Faurby, Søren ; Silvestro, Daniele ; Zizka, Alexander ; Jaramillo, Carlos ; Bacon, Christine D. ; Antonelli, and Alexandre

In: Proceedings of the National Academy of Sciences, 2020, vol. 117, no. 42, p. 26281–26287

The biological interchange between North and South America associated with the formation of the Isthmus of Panama is key to defining current gradients of species diversity. A major gap in our understanding of the interchange is its asymmetry, where mammals of North American origin attained higher diversity in South America than vice versa. The prevailing view is that this asymmetry resulted...

Université de Fribourg

Application of the Socio-Economic Impact Classification for Alien Taxa (SEICAT) to a global assessment of alien bird impacts

Evans, Thomas ; Blackburn, Tim M. ; Jeschke, Jonathan M. ; Probert, Anna F. ; Bacher, Sven

In: NeoBiota, 2020, vol. 62, p. 123–142

We use a recently proposed framework, the Socio-Economic Impact Classification for Alien Taxa (SEICAT) to undertake the first global assessment of the impacts of alien birds on human well-being. A review of the published literature and online resources was undertaken to collate information on the reported socio-economic impacts of 415 bird species with self-sustaining alien populations...

Université de Fribourg

Cenozoic evolution of the steppe-desert biome in Central Asia

Barbolini, N. ; Woutersen, A. ; Dupont-Nivet, G. ; Silvestro, Daniele ; Tardif, D. ; Coster, P. M. C. ; Meijer, N. ; Chang, C. ; Zhang, H.-X. ; Licht, A. ; Rydin, C. ; Koutsodendris, A. ; Han, F. ; Rohrmann, A. ; Liu, X.-J. ; Zhang, Y. ; Donnadieu, Y. ; Fluteau, F. ; Ladant, J.-B. ; Le Hir, G. ; Hoorn, C.

In: Science Advances, 2020, vol. 6, no. 41, p. eabb8227

The origins and development of the arid and highly seasonal steppe-desert biome in Central Asia, the largest of its kind in the world, remain largely unconstrained by existing records. It is unclear how Cenozoic climatic, geological, and biological forces, acting at diverse spatial and temporal scales, shaped Central Asian ecosystems through time. Our synthesis shows that the Central Asian...

Université de Fribourg

Circadian and genetic modulation of visually-guided navigation in Drosophila larvae

Asirim, Ece Z. ; Humberg, Tim-Henning ; Maier, G. Larisa ; Sprecher, Simon G.

In: Scientific Reports, 2020, vol. 10, no. 1, p. 2752

Organisms possess an endogenous molecular clock which enables them to adapt to environmental rhythms and to synchronize their metabolism and behavior accordingly. Circadian rhythms govern daily oscillations in numerous physiological processes, and the underlying molecular components have been extensively described from fruit flies to mammals. Drosophila larvae have relatively simple nervous...

Université de Fribourg

Arginase‐II promotes melanoma migration and adhesion through enhancing hydrogen peroxide production and STAT3 signaling

Yu, Yi ; Ladeiras, Diogo ; Xiong, Yuyan ; Boligan, Kayluz Frias ; Liang, Xiujie ; Gunten, Stephan ; Hunger, Robert E. ; Ming, Xiu‐Fen ; Yang, Zhihong

In: Journal of Cellular Physiology, 2020, p. jcp.29814

Elevated arginase type II (Arg‐II) associates with higher grade tumors. Its function and underlying molecular mechanisms in melanoma remain elusive. In the present study, we observed a significantly higher frequency of Arg‐II expression in melanoma of patients with metastasis than those without metastasis. Silencing Arg‐II in two human melanoma cell lines slowed down the cell growth,...

Université de Fribourg

Birds have peramorphic skulls, too: anatomical network analyses reveal oppositional heterochronies in avian skull evolution

Plateau, Olivia ; Foth, Christian

In: Communications Biology, 2020, vol. 3, no. 1, p. 195

In contrast to the vast majority of reptiles, the skulls of adult crown birds are characterized by a high degree of integration due to bone fusion, e.g., an ontogenetic event generating a net reduction in the number of bones. To understand this process in an evolutionary context, we investigate postnatal ontogenetic changes in the skulls of crown bird and non-avian theropods using anatomical...

Université de Fribourg

Modularity of the neck in birds (Aves)

Terray, Léa ; Plateau, Olivia ; Abourachid, Anick ; Böhmer, Christine ; Delapré, Arnaud ; la Bernardie, Xavier de ; Cornette, Raphaël

In: Evolutionary Biology, 2020, p. -

The neck connects the head and the trunk and is the key structure allowing all movements of the head. The neck morphology of birds is the most variable among living tetrapods, including significant differences in the number and shape of the cervical vertebrae. Despite these differences, according to the literature, three morphofunctional regions (i.e., modules) have been identified along the...

Université de Fribourg

First fossil frog from Antarctica: implications for Eocene high latitude climate conditions and Gondwanan cosmopolitanism of Australobatrachia

Mörs, Thomas ; Reguero, Marcelo ; Vasilyan, Davit

In: Scientific Reports, 2020, vol. 10, p. 5051

Cenozoic ectothermic continental tetrapods (amphibians and reptiles) have not been documented previously from Antarctica, in contrast to all other continents. Here we report a fossil ilium and an ornamented skull bone that can be attributed to the Recent, South American, anuran family Calyptocephalellidae or helmeted frogs, representing the first modern amphibian found in Antarctica. The two bone...