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Drawing on collective experience from ten collaborative research projects focused on the Global South, we identify three major challenges that impede the translation of research on sustainability and resilience into better-informed choices by individuals and policy-makers that in turn can support transformation to a sustainable future. The three challenges comprise: (i) converting knowledge produced during research projects into successful knowledge application; (ii) scaling up knowledge in time when research projects are short-term and potential impacts are long-term; and (iii) scaling up knowledge across space, from local research sites to larger-scale or even global impact. Some potential pathways for funding agencies to overcome these challenges include providing targeted prolonged funding for dissemination and outreach, and facilitating collaboration and coordination across different sites, research teams, and partner organizations. By systematically documenting these challenges, we hope to pave the way for further innovations in the research cycle.
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Resiliencia Psicológica , HumanosRESUMEN
Perennial grains have potential to contribute to ecological intensification of food production by enabling the direct harvest of human-edible crops without requiring annual cycles of disturbance and replanting. Studies of prototype perennial grains and other herbaceous perennials point to the ability of agroecosystems including these crops to protect water quality, enhance wildlife habitat, build soil quality, and sequester soil carbon. However, genetic improvement of perennial grain candidates has been hindered by limited investment due to uncertainty about whether the approach is viable. As efforts to develop perennial grain crops have expanded in past decades, critiques of the approach have arisen. With a recent report of perennial rice producing yields equivalent to those of annual rice over eight consecutive harvests, many theoretical concerns have been alleviated. Some valid questions remain over the timeline for new crop development, but we argue these may be mitigated by implementation of recent technological advances in crop breeding and genetics such as low-cost genotyping, genomic selection, and genome editing. With aggressive research investment in the development of new perennial grain crops, they can be developed and deployed to provide atmospheric greenhouse gas reductions.
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Agricultura , Fitomejoramiento , Humanos , Grano Comestible , Productos Agrícolas , SueloRESUMEN
Perennial grain crops could make a valuable addition to sustainable agriculture, potentially even as an alternative to their annual counterparts. The ability of perennials to grow year after year significantly reduces the number of agricultural inputs required, in terms of both planting and weed control, while reduced tillage improves soil health and on-farm biodiversity. Presently, perennial grain crops are not grown at large scale, mainly due to their early stages of domestication and current low yields. Narrowing the yield gap between perennial and annual grain crops will depend on characterizing differences in their life cycles, resource allocation, and reproductive strategies and understanding the trade-offs between annualism, perennialism, and yield. The genetic and biochemical pathways controlling plant growth, physiology, and senescence should be analyzed in perennial crop plants. This information could then be used to facilitate tailored genetic improvement of selected perennial grain crops to improve agronomic traits and enhance yield, while maintaining the benefits associated with perennialism.
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More than 150 years ago, in 1866, Ernst Haeckel published a book in two volumes called Generelle Morphologie der Organismen (General Morphology of Organisms) in the first volume of which he formulated his biogenetic law, famously stating that ontogeny recapitulates phylogeny. Here, we describe Haeckel's original idea as first formulated in the Generelle Morphologie der Organismen and later further developed in other publications until the present situation in which molecular data are used to test the "hourglass model," which can be seen as a modern version of the biogenetic law. We also tell the story about his discovery, while traveling in Norway, of an unknown organism, Magosphaera planula, that was important in that it helped to precipitate his ideas into what was to become the Gastraea theory. We also follow further development and reformulations of the Gastraea theory by other scientists, notably the Russian school. Elias Metchnikoff developed the Phagocytella hypothesis for the origin of metazoans based on studies of a colonial flagellate. Alexey Zakhvatin focused on deducing the ancestral life cycle and the cell types of the last common ancestor of all metazoans, and Kirill V. Mikhailov recently pursued this line of research further.
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Evolución Biológica , Biología Evolutiva , Animales , FilogeniaRESUMEN
The vertebrate head as a major novelty is directly linked to the evolutionary success of the vertebrates. Sequential information on the embryonic pattern of cartilaginous head development are scarce, but important for the understanding of its evolution. In this study, we use the oriental fire bellied toad, Bombina orientalis, a basal anuran to investigate the sequence and timing of larval cartilaginous development of the head skeleton from the appearance of mesenchymal Anlagen in post-neurulation stages until the premetamorphic larvae. We use different methodological approaches like classic histology, clearing and staining, and antibody staining to examine the larval skeletal morphology. Our results show that in contrast to other vertebrates, the ceratohyals are the first centers of chondrification. They are followed by the palatoquadrate and the basihyal. The latter later fuses to the ceratohyal and the branchial basket. Anterior elements like Meckel's cartilage and the rostralia are delayed in development and alter the ancestral anterior posterior pattern observed in other vertebrates. The ceratobranchials I-IV, components of the branchial basket, follow this strict anterior-posterior pattern of chondrification as reported in other amphibians. Chondrification of different skeletal elements follows a distinct pattern and the larval skeleton is nearly fully developed at Gosner Stage 28. We provide baseline data on the pattern and timing of early cartilage development in a basal anuran species, which may serve as guidance for further experimental studies in this species as well as an important basis for the understanding of the evolutionary changes in head development among amphibians and vertebrates.
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Anuros/crecimiento & desarrollo , Cráneo/crecimiento & desarrollo , Animales , Anuros/anatomía & histología , Región Branquial/anatomía & histología , Cartílago/crecimiento & desarrollo , Maxilares/anatomía & histología , Larva/crecimiento & desarrolloRESUMEN
BACKGROUND: Fox genes are a large family of transcription factors that play diverse roles in the immune system, metabolism, cancer, cell cycle, and animal development. It has been shown that FoxN3 is indispensable for normal craniofacial development in the mouse and the African clawed frog, Xenopus laevis. Morpholino-mediated knockdown of FoxN3 in X. laevis delays overall development of early tadpole stages and causes eye defects, the absence of some cranial nerve branches, and malformations of the cranial skeleton and some cranial muscles, while the skeleton, nerves and muscles of the trunk are unaffected. RESULTS: We report a delay in heart morphogenesis, the absence of the interatrial septum, and a reduction and compaction of the ventricular trabeculation after knockdown of FoxN3 in X. laevis. Furthermore, we found malformations of the cucullaris and diaphragmatico-branchialis muscles, two head muscles that develop in the head/trunk interface of X. laevis. CONCLUSIONS: FoxN3 is necessary for the development of the interatrial septum and trabeculae in the frog heart, as well as the cranial muscles developing in the head/trunk interface. This gives the first evidence for a dependence on the head myogenic program of the cucullaris muscle in an anuran species.
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Tabique Interatrial/crecimiento & desarrollo , Factores de Transcripción Forkhead/fisiología , Ventrículos Cardíacos/crecimiento & desarrollo , Desarrollo de Músculos , Proteínas de Xenopus/fisiología , Xenopus laevis/crecimiento & desarrollo , Xenopus laevis/metabolismo , Animales , Cabeza/fisiología , Tabiques Cardíacos/crecimiento & desarrolloRESUMEN
The Haeckel reception in different European countries has received some attention from historians of biology, but the reception in Scandinavia remains relatively unknown. We have found letters to and from Haeckel to Swedish scientists and students in the Ernst Haeckel House in Jena and in the archives of the Royal Swedish Academy of Sciences (RSAS) in Stockholm. Here we present correspondence with Wilhelm Leche, Sven Lovén, and M. G. Retzius, all prominent scientists in Stockholm at the time and members of the RSAS. Most letters cover scientific matters such as the biogenetic law, or are concerned with practical matters such as loans of specimens. Sometimes also political issues are mentioned. In addition, we present a letter from Anton Nyström, the radical physician, in which he tells of his struggles with the church and the conservatives, and a letter from the explorer and geographer Sven Hedin, written in the midst of the First World War. Examples are also given of letters to Haeckel from students that were inspired by his world view as laid out in "Natural History of Creation". In conclusion, Haeckel's correspondence with his colleagues in Stockholm gives insights not only into how Haeckel's ideas were received at the time, but also into the relationships between the Swedish scientists, including their conflicting political views.
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Biología Evolutiva/historia , Animales , Evolución Biológica , Alemania , Historia del Siglo XIX , Historia del Siglo XX , Filogenia , SueciaRESUMEN
In our era of computers and computer models, the importance of physical or graphical models for both research and education in developmental biology (embryology) is often forgotten or at least underappreciated. Still, one important aspect of embryology is the (evolutionary) developmental anatomy of both human and animal embryos. Here, we present a short history of the visualization of Ernst Haeckel's "biogenetic law" and his "gastraea theory" in biology textbooks from the German Democratic Republic (GDR) between 1951 and 1988. Our analysis of GDR textbooks showed embryology was integrated into different disciplines and remained an educational constant within the school textbooks throughout the GDR despite various educational reforms. While the majority of these textbooks failed to reference either Ernst Haeckel or his contributions to embryology, they often did mention Haeckel in sections dedicated to the theory of evolution and the promotion of Soviet ideals such as materialism.
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Biología Evolutiva , Embriología/educación , Embriología/historia , Animales , Evolución Biológica , Alemania Oriental , Historia del Siglo XX , Humanos , Filogenia , Instituciones Académicas , Libros de Texto como AsuntoRESUMEN
The acquisition of a movable jaw and a jaw joint are key events in gnathostome evolution. Jaws are derived from the neural crest derived pharyngeal skeleton and the transition from jawless to jawed vertebrates consists of major morphological changes, which must have a genetic foundation. Recent studies on the effects of bapx1 knockdown in fish and chicken indicate that bapx1 has acquired such a role in primary jaw joint development during vertebrate evolution, but evidence from amphibians is missing so far. In the present study, we use Ambystoma mexicanum, Bombina orientalis, and Xenopus laevis to investigate the effects of bapx1 knockdown on the development of these three different amphibians. Using morpholinos we downregulated the expression of bapx1 and obtain morphants with altered mandibular arch morphology. In the absence of bapx1 Meckels cartilage and the palatoquadrate jaw joint initially develop separately but during further development the joint cavity between both fills with chondrocytes. This results in the fusion of both cartilages and the loss of the jaw joint. Despite this the jaw itself remains usable for feeding and breathing. We show that bapx1 plays a role in jaw joint maintenance during development and that the morphants morphology possibly mirrors the morphology of the jawless ancestors of the gnathostomes.
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Anuros/crecimiento & desarrollo , Proteínas de Homeodominio/metabolismo , Maxilares/embriología , Articulaciones/embriología , Ambystoma mexicanum/genética , Ambystoma mexicanum/crecimiento & desarrollo , Animales , Anuros/clasificación , Anuros/genética , Región Branquial/citología , Región Branquial/metabolismo , Condrocitos/metabolismo , Técnicas de Silenciamiento del Gen , Cabeza/embriología , Proteínas de Homeodominio/genética , Maxilares/metabolismo , Articulaciones/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Proteínas de Xenopus/genética , Proteínas de Xenopus/metabolismo , Xenopus laevis/genética , Xenopus laevis/crecimiento & desarrolloRESUMEN
BACKGROUND: The emergence of novel structures during evolution is crucial for creating variation among organisms, but the underlying processes which lead to the emergence of evolutionary novelties are poorly understood. The gnathostome jaw joint is such a novelty, and the incorporation of bapx1 expression into the intermediate first pharyngeal arch may have played a major role in the evolution of this joint. Knockdown experiments revealed that loss of bapx1 function leads to the loss of the jaw joint, because Meckel's cartilage and the palatoquadrate fuse during development. We used Xenopus laevis and Ambystoma mexicanum to further investigate the function of bapx1 in amphibians. Bapx1 expression levels were upregulated through the use of Ly-294,002 and we investigated the potential consequences of the enhanced bapx1 expression in amphibians to test the hypothesized joint inducing function of bapx1. RESULTS: We show that Ly-294,002 upregulates bapx1 expression in vivo. Additionally, ectopic mandibular arch derived cartilages develop after Ly-294,002 treatment. These ectopic cartilages are dorsoventrally oriented rods situated lateral to the palatoquadrate. The development of these additional cartilages did not change the muscular arrangement of mandibular arch-derived muscles. CONCLUSIONS: Development of additional mandibular cartilages is not unusual in larval anurans. Therefore, changes in the bapx1 expression during evolution may have been the reason for the development of several additional cartilages in the larval anuran jaw. Furthermore, our observations imply a joint-promoting function of bapx1, which further substantiates its hypothetical role in the evolution of the gnathostome jaw joint.
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The skeleton of the jaws and neurocranium of sturgeons (Acipenseridae) are connected only through the hyoid arch. This arrangement allows considerable protrusion and retraction of the jaws and is highly specialized among ray-finned fishes (Actinopterygii). To better understand the unique morphology and the evolution of the jaw apparatus in Acipenseridae, we investigated the development of the muscles of the mandibular and hyoid arches of the Siberian sturgeon, Acipenser baerii. We used a combination of antibody staining and formalin-induced fluorescence of tissues imaged with confocal microscopy and subsequent three-dimensional reconstruction. These data were analyzed to address the identity of previously controversial and newly discovered muscle portions. Our results indicate that the anlagen of the muscles in A. baerii develop similarly to those of other actinopterygians, although they differ by not differentiating into distinct muscles. This is exemplified by the subpartitioning of the m. adductor mandibulae as well as the massive m. protractor hyomandibulae, for which we found a previously undescribed portion in each. The importance of paedomorphosis for the evolution of Acipenseriformes has been discussed before and our results indicate that the muscles of the mandibular and the hyoid may be another example for heterochronic evolution.
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Peces/anatomía & histología , Peces/crecimiento & desarrollo , Hueso Hioides/anatomía & histología , Mandíbula/anatomía & histología , Desarrollo de Músculos , Músculos/anatomía & histología , Animales , Imagenología TridimensionalRESUMEN
Lungfishes are the extant sister group of tetrapods. As such, they are important for the study of evolutionary processes involved in the water to land transition of vertebrates. The evolution of a true neck, that is, the complete separation of the pectoral girdle from the cranium, is one of the most intriguing morphological transitions known among vertebrates. Other salient changes involve new adaptations for terrestrial feeding, which involves both the cranium and its associated musculature. Historically, the cranium has been extensively investigated, but the development of the cranial muscles much less so. Here, we present a detailed study of cephalic muscle development in the Australian lungfish, Neoceratodus forsteri, which is considered to be the sister taxon to all other extant lungfishes. Neoceratodus shows several developmental patterns previously described in other taxa; the tendency of muscles to develop from anterior to posterior, from their region of origin toward insertion, and from lateral to ventral/medial (outside-in), at least in the branchial arches. The m.protractor pectoralis appears to develop as an extension of the most posterior m.levatores arcuum branchialium, supporting the hypothesis that the m.cucullaris and its derivatives (protractor pectoralis, levatores arcuum branchialium) are branchial muscles. We present a new hypothesis regarding the homology of the ventral branchial arch muscles (subarcualis recti and obliqui, transversi ventrales) in lungfishes and amphibians. Moreover, the morphology and development of the cephalic muscles confirms that extant lungfishes are neotenic and have been strongly influenced via paedomorphosis during their evolutionary history.
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Peces/anatomía & histología , Peces/crecimiento & desarrollo , Desarrollo de Músculos , Músculos/anatomía & histología , Animales , Australia , Músculos/diagnóstico por imagen , Cuello/anatomía & histología , Cráneo/anatomía & histología , Cráneo/diagnóstico por imagenRESUMEN
Xenopus laevis is one of the most widely used model organism in neurobiology. It is therefore surprising, that no detailed and complete description of the cranial nerves exists for this species. Using classical histological sectioning in combination with fluorescent whole mount antibody staining and micro-computed tomography we prepared a detailed innervation map and a freely-rotatable three-dimensional (3D) model of the cranial nerves and anterior-most spinal nerves of early X. laevis tadpoles. Our results confirm earlier descriptions of the pre-otic cranial nerves and present the first detailed description of the post-otic cranial nerves. Tracing the innervation, we found two previously undescribed head muscles (the processo-articularis and diaphragmatico-branchialis muscles) in X. laevis. Data on the cranial nerve morphology of tadpoles are scarce, and only one other species (Discoglossus pictus) has been described in great detail. A comparison of Xenopus and Discoglossus reveals a relatively conserved pattern of the post-otic and a more variable morphology of the pre-otic cranial nerves. Furthermore, the innervation map and the 3D models presented here can serve as an easily accessible basis to identify alterations of the innervation produced by experimental studies such as genetic gain- and loss of function experiments.
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Nervios Craneales/diagnóstico por imagen , Imagenología Tridimensional , Nervios Espinales/diagnóstico por imagen , Tomógrafos Computarizados por Rayos X , Xenopus laevis/anatomía & histología , Animales , Nervios Craneales/metabolismo , Modelos Neurológicos , Músculos/anatomía & histología , Músculos/metabolismo , Nervios Espinales/metabolismo , Proteínas de Xenopus/metabolismoRESUMEN
Xenopus laevis is widely used as a model organism in biological research. Morphological descriptions of the larval cartilaginous skeleton are more than half a century old and comprehensive studies of early cartilage differentiation and development are missing. A proper understanding of early cranial skeletal development in X. laevis requires a detailed description that can function as a baseline for experimental studies. This basis makes it possible to evaluate skeletal defects produced by experiments on gene interactions, such as gain- or loss-of function experiments. In this study, we provide a detailed description of the pattern and timing of early cartilage differentiation and development in the larval head of X. laevis. Methods used include antibody staining, confocal laser scanning microscopy and 3D-reconstruction. Results were than compared to earlier studies based on classical histological approaches and clearing-and-staining. The first cartilage to chondrify is, in contrast to other vertebrates investigated so far, the ceratohyal. The components of the branchial basket chondrify in anterior-to-posterior direction as reported for other amphibians. Chondrification of different cartilages begins at different stages and the majority of cartilages are fully developed at Ziermann and Olsson stage 17. Our baseline data on the pattern and timing of early cartilaginous development in X. laevis is useful for evaluation of experiments which alter head skeletal development as well as for identifying heterochronic shifts in head development in other amphibians.
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Cráneo/crecimiento & desarrollo , Xenopus laevis/crecimiento & desarrollo , Animales , Cartílago/anatomía & histología , Cartílago/crecimiento & desarrollo , Colágeno/metabolismo , Cabeza/anatomía & histología , Imagenología Tridimensional , Larva/anatomía & histología , Larva/crecimiento & desarrollo , Cráneo/citología , Factores de Tiempo , Xenopus laevis/anatomía & histologíaRESUMEN
The vertebrate head/trunk interface is the region of the body where the different developmental programs of the head and trunk come in contact. Many anatomical structures that develop in this transition zone differ from similar structures in the head or the trunk. This is best exemplified by the cucullaris/trapezius muscle, spanning the head/trunk interface by connecting the head to the pectoral girdle. The source of this muscle has been claimed to be either the unsegmented head mesoderm or the somites of the trunk. However most recent data on the development of the cucullaris muscle are derived from tetrapods and information from actinopterygian taxa is scarce. We used classical histology in combination with fluorescent whole-mount antibody staining and micro-computed tomography to investigate the developmental pattern of the cucullaris and the branchial muscles in a basal actinopterygian, the Longnose gar (Lepisosteus osseus). Our results show (1) that the cucullaris has been misidentified in earlier studies on its development in Lepisosteus. (2) Cucullaris development is delayed compared to other head and trunk muscles. (3) This developmental pattern of the cucullaris is similar to that reported from some tetrapod taxa. (4) That the retractor dorsalis muscle of L. osseus shows a delayed developmental pattern similar to the cucullaris. Our data are in agreement with an explanatory scenario for the cucullaris development in tetrapods, suggesting that these mechanisms are conserved throughout the Osteichthyes. Furthermore the developmental pattern of the retractor dorsalis, also spanning the head/trunk interface, seems to be controlled by similar mechanisms.
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Evolución Biológica , Peces/embriología , Cabeza/embriología , Músculo Esquelético/embriología , Músculos del Cuello/embriología , Animales , Región Branquial/anatomía & histología , Peces/anatomía & histología , Cabeza/anatomía & histología , Músculo Esquelético/anatomía & histología , Músculos del Cuello/anatomía & histologíaRESUMEN
150 years ago, in 1866, Ernst Haeckel published a book in two volumes called "Generelle Morphologie der Organismen" (General Morphology of Organisms) in which he formulated his biogenetic law, famously stating that ontogeny recapitulates phylogeny. Here we describe Haeckel's original idea and follow its development in the thinking of two scientists inspired by Haeckel, Alexei Sewertzoff and Adolf Naef. Sewertzoff and Naef initially approached the problem of reformulating Haeckel's law in similar ways, and formulated comparable hypotheses at a purely descriptive level. But their theoretical viewpoints were crucially different. While Sewertzoff laid the foundations for a Darwinian evolutionary morphology and is regarded as a forerunner of the Modern Synthesis, Naef was one of the most important figures in 'idealistic morphology', usually seen as a type of anti-Darwinism. Both Naef and Sewertzoff aimed to revise Haeckel's biogenetic law and came to comparable conclusions at the empirical level. We end our review with a brief look at the present situation in which molecular data are used to test the "hour-glass model", which can be seen as a modern version of the biogenetic law.
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Biología Evolutiva/historia , Aprendizaje , Animales , Evolución Biológica , Alemania , Historia del Siglo XIX , Historia del Siglo XX , Modelos Biológicos , Filogenia , Selección Genética , ZoologíaRESUMEN
The head is considered the major novelty of the vertebrates and directly linked to their evolutionary success. Its form and development as well as its function, for example in feeding, is of major interest for evolutionary biologists. In this study, we describe the skeletal development of the cranium and pectoral girdle in Siberian (Acipenser baerii) and Russian sturgeon (A. gueldenstaedtii), two species that are commonly farmed in aquaculture and increasingly important in developmental studies. This study comprises the development of the neuro-, viscero- and dermatocranium and the dermal and chondral components of the pectoral girdle, from first condensation of chondrocytes in prehatchlings to the early juvenile stage and reveals a clear pattern in formation. The otic capsules, the parachordal cartilages, and the trabeculae cranii are the first centers of chondrification, at 8.4mm TL. These are followed by the mandibular, then the hyoid, and later the branchial arches. Teeth form early on the dentary, dermopalatine, and palatopterygoid, and then appear later in the buccal cavity as dorsal and ventral toothplates. With ongoing chondrification in the neurocranium a capsule around the brain and a strong rostrum are formed. Dermal ossifications start to form before closure of the dorsal neurocranial fenestrae. Perichondral ossification of cartilage bones occurs much later in ontogeny. Our results contribute data bearing on the homology of elements such as the lateral rostral canal bone that we regard homologous to the antorbital of other actinopterygians based on its sequence of formation, position and form. We further raise doubts on the homology of the posterior ceratobranchial among Actinopteri based on the formation of the hyoid arch elements. We also investigate the basibranchials and the closely associated unidentified gill-arch elements and show that they are not homologous. J. Morphol. 278:418-442, 2017. © 2017 Wiley Periodicals, Inc.
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Huesos de la Extremidad Superior/crecimiento & desarrollo , Peces/crecimiento & desarrollo , Cráneo/crecimiento & desarrollo , Animales , Evolución Biológica , Huesos de la Extremidad Superior/embriología , Región Branquial/embriología , Región Branquial/crecimiento & desarrollo , Cartílago/crecimiento & desarrollo , Peces/embriología , Peces/genética , Hueso Hioides/embriología , Hueso Hioides/crecimiento & desarrollo , Osteogénesis , Cráneo/embriologíaRESUMEN
Resilience is often promoted as a boundary concept to integrate the social and natural dimensions of sustainability. However, it is a troubled dialogue from which social scientists may feel detached. To explain this, we first scrutinize the meanings, attributes, and uses of resilience in ecology and elsewhere to construct a typology of definitions. Second, we analyze core concepts and principles in resilience theory that cause disciplinary tensions between the social and natural sciences (system ontology, system boundary, equilibria and thresholds, feedback mechanisms, self-organization, and function). Third, we provide empirical evidence of the asymmetry in the use of resilience theory in ecology and environmental sciences compared to five relevant social science disciplines. Fourth, we contrast the unification ambition in resilience theory with methodological pluralism. Throughout, we develop the argument that incommensurability and unification constrain the interdisciplinary dialogue, whereas pluralism drawing on core social scientific concepts would better facilitate integrated sustainability research.
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Ernst Haeckel formulated his biogenetic law, famously stating that ontogeny recapitulates phylogeny, in 1872. The Russian evolutionist Alexei Sewertzoff, and the Swiss-born zoologist Adolf Naef were among those who revised Haeckel's law, thus changing the course of evolutionary theory and of developmental biology. Although Sewertzoff and Naef approached the problem in a similar way and formulated similar hypotheses at a purely descriptive level, their theoretical viewpoints were crucially different. While Sewertzoff laid the foundations for a Darwinian evolutionary morphology and is regarded as a forerunner of the modern synthesis, Naef was one of the most important figures in "idealistic morphology", which is usually seen as a type of anti-Darwinism. Both Naef and Sewertzoff aimed to revise Haeckel's biogenetic law and came to comparable conclusions at the empirical level. This paper is an attempt to explain how their fundamentally different theoretical backgrounds influenced their views on the relationship between ontogeny and phylogeny.
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Evolución Biológica , Biología Evolutiva/historia , Filogenia , Historia del Siglo XIX , Historia del Siglo XX , Federación de Rusia , SuizaRESUMEN
Today the Mexican axolotl is critically endangered in its natural habitat in lakes around Mexico City, but thrives in research laboratories around the world, where it is used for research on development, regeneration, and evolution. Here, we concentrate on the early history of the axolotl as a laboratory animal to celebrate that the first living axolotls arrived in Paris in 1864, 150 years ago. Maybe surprisingly, at first the axolotl was distributed across Europe without being tied to specific research questions, and amateurs engaged in acclimatization and aquarium movements played an important role for the rapid proliferation of the axolotl across the continent. But the aquarium also became an important part of the newly established laboratory, where more and more biological and medical research now took place. Early scientific interest focused on the anatomical peculiarities of the axolotl, its rare metamorphosis, and whether it was a larva or an adult. Later, axolotl data was used to argue both for (by August Weismann and others) and against (by e.g., Albert von Kölliker) Darwinism, and the axolotl even had a brief history as a laboratory animal used in a failed attempt to prove Lysenkoism in Jena, Germany. Nowadays, technical developments such as transgenic lines, and the very strong interest in stem cell and regeneration research has again catapulted the axolotl into becoming an important laboratory animal.