166 research outputs found
Speciation Success of Polyploid Plants Closely Relates to the Regulation of Meiotic Recombination
Polyploidization is a widespread phenomenon, especially in flowering plants that have all undergone at least one event of whole genome duplication during their evolutionary history. Consequently, a large range of plants, including many of the worldâs crops, combines more than two sets of chromosomes originating from the same (autopolyploids) or related species (allopolyploids). Depending on the polyploid formation pathway, different patterns of recombination will be promoted, conditioning the level of heterozygosity. A polyploid population harboring a high level of heterozygosity will produce more genetically diverse progenies. Some of these individuals may show a better adaptability to different ecological niches, increasing their chance for successful establishment through natural selection. Another condition for young polyploids to survive corresponds to the formation of well-balanced gametes, assuring a sufficient level of fertility. In this review, we discuss the consequences of polyploid formation pathways, meiotic behavior and recombination regulation on the speciation success and maintenance of polyploid species
Eye image effect in the context of pedestrian safety: a French questionnaire study [version 2; peer review: 2 approved]
Human behavior is influenced by the presence of others, which scientists also call âthe audience effectâ. The use of social control to produce more cooperative behaviors may positively influence road use and safety. This study uses an online questionnaire to test how eyes images affect the behavior of pedestrians when crossing a road. Different eyes images of men, women and a child with different facial expressions -neutral, friendly and angry- were presented to participants who were asked what they would feel by looking at these images before crossing a signalized road. Participants completed a questionnaire of 20 questions about pedestrian behaviors (PBQ). The questionnaire was received by 1,447 French participants, 610 of whom answered the entire questionnaire. Seventy-one percent of participants were women, and the mean age was 35 ± 14 years. Eye images give individuals the feeling they are being observed at 33%, feared at 5% and surprised at 26%, and thus seem to indicate mixed results about avoiding crossing at the red light. The expressions shown in the eyes are also an important factor: feelings of being observed increased by about 10-15% whilst feelings of being scared or inhibited increased by about 5% as the expression changed from neutral to friendly to angry. No link was found between the results of our questionnaire and those of the Pedestrian Behavior Questionnaire (PBQ). This study shows that the use of eye images could reduce illegal crossings by pedestrians, and is thus of key interest as a practical road safety tool. However, the effect is limited and how to increase this nudge effect needs further consideration
New indices to characterize drawing behavior in humans (Homo sapiens) and chimpanzees (Pan troglodytes)
Techniques used in cave art suggest that drawing skills emerged long before the oldest known representative human productions (44, 000 years BC). This study seeks to improve our knowledge of the evolutionary origins and the ontogenetic development of drawing behavior by studying drawings of humans (Nâ=â178, 3- to 10-year-old children and adults) and chimpanzees (Nâ=â5). Drawings were characterized with an innovative index based on spatial measures which provides the degree of efficiency for the lines that are drawn. Results showed that this index was lowest in chimpanzees, increased and reached its maximum between 5-year-old and 10-year-old children and decreased in adults, whose drawing efficiency was reduced by the addition of details. Drawings of chimpanzees are not random suggesting that their movements are constrained by cognitive or locomotor aspect and we cannot conclude to the absence of representativeness. We also used indices based on colors and time and asked children about what they drew. These indices can be considered relevant tools to improve our understanding of drawing development and evolution in hominids
Exploration of the creative processes in animals, robots, and AI: who holds the authorship?
Picture a simple scenario: a worm, in its modest way, traces a trail of paint as it moves across a sheet of paper. Now shift your imagination to a more complex scene, where a chimpanzee paints on another sheet of paper. A simple question arises: Do you perceive an identical creative process in these two animals? Can both of these animals be designated as authors of their creation? If only one, which one? This paper delves into the complexities of authorship, consciousness, and agency, unpacking the nuanced distinctions between such scenarios and exploring the underlying principles that define creative authorship across different forms of life. It becomes evident that attributing authorship to an animal hinges on its intention to create, an aspect intertwined with its agency and awareness of the creative act. These concepts are far from straightforward, as they traverse the complex landscapes of animal ethics and law. But our exploration does not stop there. Now imagine a robot, endowed with artificial intelligence, producing music. This prompts us to question how we should evaluate and perceive such creations. Is the creative process of a machine fundamentally different from that of an animal or a human? As we venture further into this realm of human-made intelligence, we confront an array of ethical, philosophical, and legal quandaries. This paper provides a platform for a reflective discussion: ethologists, neuroscientists, philosophers, and bioinformaticians converge in a multidisciplinary dialogue. Their insights provide valuable perspectives for establishing a foundation upon which to discuss the intricate concepts of authorship and appropriation concerning artistic works generated by non-human entities
Centronuclear myopathy in labrador retrievers: a recent founder mutation in the PTPLA gene has rapidly disseminated worldwide
Centronuclear myopathies (CNM) are inherited congenital disorders characterized by an excessive number of internalized nuclei. In humans, CNM results from ~70 mutations in three major genes from the myotubularin, dynamin and amphiphysin families. Analysis of animal models with altered expression of these genes revealed common defects in all forms of CNM, paving the way for unified pathogenic and therapeutic mechanisms. Despite these efforts, some CNM cases remain genetically unresolved. We previously identified an autosomal recessive form of CNM in French Labrador retrievers from an experimental pedigree, and showed that a loss-of-function mutation in the protein tyrosine phosphatase-like A (PTPLA) gene segregated with CNM. Around the world, client-owned Labrador retrievers with a similar clinical presentation and histopathological changes in muscle biopsies have been described. We hypothesized that these Labradors share the same PTPLA<sup>cnm</sup> mutation. Genotyping of an international panel of 7,426 Labradors led to the identification of PTPLA<sup>cnm</sup> carriers in 13 countries. Haplotype analysis demonstrated that the PTPLA<sup>cnm</sup> allele resulted from a single and recent mutational event that may have rapidly disseminated through the extensive use of popular sires. PTPLA-deficient Labradors will help define the integrated role of PTPLA in the existing CNM gene network. They will be valuable complementary large animal models to test innovative therapies in CNM
Progressive Structural Defects in Canine Centronuclear Myopathy Indicate a Role for HACD1 in Maintaining Skeletal Muscle Membrane Systems
Mutations in HACD1/PTPLA cause recessive congenital myopathies in humans and dogs. Hydroxyacyl-coA dehydratases are required for elongation of very long chain fatty acids, and HACD1 has a role in early myogenesis, but the functions of this striated muscle-specific enzyme in more differentiated skeletal muscle remain unknown. Canine HACD1 deficiency is histopathologically classified as a centronuclear myopathy (CNM). We investigated the hypothesis that muscle from HACD1-deficient dogs has membrane abnormalities in common with CNMs with different genetic causes. We found progressive changes in tubuloreticular and sarcolemmal membranes and mislocalized triads and mitochondria in skeletal muscle from animals deficient in HACD1. Furthermore, comparable membranous abnormalities in cultured HACD1-deficient myotubes provide additional evidence that these defects are a primary consequence of altered HACD1 expression. Our novel findings, including T-tubule dilatation and disorganization, associated with defects in this additional CNM-associated gene provide a definitive pathophysiologic link with these disorders, confirm that dogs deficient in HACD1 are relevant models, and strengthen the evidence for a unifying pathogenesis in CNMs via defective membrane trafficking and excitation-contraction coupling in muscle. These results build on previous work by determining further functional roles of HACD1 in muscle and provide new insight into the pathology and pathogenetic mechanisms of HACD1 CNM. Consequently, alterations in membrane properties associated with HACD1 mutations should be investigated in humans with related phenotypes
Multidimensional Scaling Reveals the Main Evolutionary Pathways of Class A G-Protein-Coupled Receptors
Class A G-protein-coupled receptors (GPCRs) constitute the largest family of transmembrane receptors in the human genome. Understanding the mechanisms which drove the evolution of such a large family would help understand the specificity of each GPCR sub-family with applications to drug design. To gain evolutionary information on class A GPCRs, we explored their sequence space by metric multidimensional scaling analysis (MDS). Three-dimensional mapping of human sequences shows a non-uniform distribution of GPCRs, organized in clusters that lay along four privileged directions. To interpret these directions, we projected supplementary sequences from different species onto the human space used as a reference. With this technique, we can easily monitor the evolutionary drift of several GPCR sub-families from cnidarians to humans. Results support a model of radiative evolution of class A GPCRs from a central node formed by peptide receptors. The privileged directions obtained from the MDS analysis are interpretable in terms of three main evolutionary pathways related to specific sequence determinants. The first pathway was initiated by a deletion in transmembrane helix 2 (TM2) and led to three sub-families by divergent evolution. The second pathway corresponds to the differentiation of the amine receptors. The third pathway corresponds to parallel evolution of several sub-families in relation with a covarion process involving proline residues in TM2 and TM5. As exemplified with GPCRs, the MDS projection technique is an important tool to compare orthologous sequence sets and to help decipher the mutational events that drove the evolution of protein families
Can Monkeys Make Investments Based on Maximized Pay-off?
Animals can maximize benefits but it is not known if they adjust their investment according to expected pay-offs. We investigated whether monkeys can use different investment strategies in an exchange task. We tested eight capuchin monkeys (Cebus apella) and thirteen macaques (Macaca fascicularis, Macaca tonkeana) in an experiment where they could adapt their investment to the food amounts proposed by two different experimenters. One, the doubling partner, returned a reward that was twice the amount given by the subject, whereas the other, the fixed partner, always returned a constant amount regardless of the amount given. To maximize pay-offs, subjects should invest a maximal amount with the first partner and a minimal amount with the second. When tested with the fixed partner only, one third of monkeys learned to remove a maximal amount of food for immediate consumption before investing a minimal one. With both partners, most subjects failed to maximize pay-offs by using different decision rules with each partner' quality. A single Tonkean macaque succeeded in investing a maximal amount to one experimenter and a minimal amount to the other. The fact that only one of over 21 subjects learned to maximize benefits in adapting investment according to experimenters' quality indicates that such a task is difficult for monkeys, albeit not impossible
Ătude comparative des facultĂ©s dâĂ©change chez les primates non humains.
Trading is a hallmark of human behaviour, and exchanges or even gifts are not commonlyseen in other species. Across the animal kingdom, and especially in primates, reciprocalinteractions are reported in a diversity of contexts such as social grooming, coalitions andfood sharing. Some authors propose that these interactions are based on calculated reciprocity,a mechanism by which individuals keep track of what has been given and returned andconsider it for future exchanges. However, the observed interactions do not provide validsupport about behaviours contingency and calculation from individuals. This work aimed atstudying the conditions necessary for calculated reciprocity to occur (1) by testing whetherprimates understand the temporal cost associated with an exchange, (2) by studying thecapacity of primates to take a risk during an exchange and (3) by searching whether primatesare capable to engage with a conspecific in a calculated exchange under controlled conditions.I tested seven species of non human primates in different exchange tasks: long-tailedmacaques (Macaca fascicularis), Tonkean macaques (M. Tonkeana), capuchin monkeys(Cebus apella), chimpanzees (Pan troglodytes), bonobos (Pan paniscus), orang-utans (Pongopygmaeus), gorillas (Gorilla gorilla). When considering the temporal dimension of exchange,I observed some variations in the capacity of primates to delay gratification. For a rewardequivalent to eight times an initial item, capuchins could wait for 10-20 s, macaques for 40-80s and chimpanzees for 1-2 min. In all species, both estimation of the value of goods beingexchanged and anticipation of the waiting duration underlie the decision of individuals. Whenconsidering the capacity of primates to engage in a risky exchange, it appeared that mostorang-utans and capuchins exchanged when the chance to gain was higher than the chance tolose. Most long-tailed macaques exchanged even when the chance to gain was lower than thechance to lose. Primates are capable to estimate gain and loss probabilities and to consider itwhen deciding to engage or not in an exchange. When considering the capacity of primates toreciprocate, two orang-utans were able to engage in a system of exchanges that was bothstable and calculated. Contrary to orang-utans, only few begging gestures and gifts wereobserved in chimpanzees, bonobos and gorillas; and individuals were not capable toreciprocate. In capuchins and macaques, no begging gesture nor gifts has been observed.Although spontaneous exchange is difficult in non-human primates, this work shows that theypossess some abilities to evaluate the value of goods, to accept a loss and to delaygratification, which are among the required capacities underlying economics transactions asobserved in human beings.LâĂȘtre humain se distingue des autres espĂšces par le dĂ©veloppement des transactionsĂ©conomiques. Des interactions rĂ©ciproques surviennent chez des animaux comme les primatesdans le toilettage social, le soutien dans les conflits ou le partage de nourriture, par exemple.Selon certains auteurs, ces interactions sont basĂ©es sur le mĂ©canisme de la rĂ©ciprocitĂ©calculĂ©e, câest-Ă -dire que les sujets mĂ©morisent les biens ou services donnĂ©s et reçus, et entiennent compte dans leurs Ă©changes futurs. Cependant, la seule observation des interactionsne permet pas de conclure Ă la contingence des comportements ou Ă un calcul de la part desindividus. Ce travail de thĂšse a eu pour objectif dâĂ©tudier les conditions de la rĂ©ciprocitĂ©calculĂ©e (1) en testant si les primates intĂšgrent le coĂ»t temporel associĂ© Ă un Ă©change, (2) enĂ©tudiant leur aptitude Ă prendre en compte le risque inhĂ©rent Ă la situation dâĂ©change, et (3) enrecherchant sâils peuvent sâengager avec un congĂ©nĂšre dans des Ă©changes de type calculĂ© dansdes conditions contrĂŽlĂ©es. Jâai testĂ© sept espĂšces de primates dans diffĂ©rentes tĂąchesexpĂ©rimentales basĂ©es sur le modĂšle de lâĂ©change : macaques Ă longue queue (Macacafascicularis), macaques de Tonkean (M. tonkeana), capucins bruns (Cebus apella),chimpanzĂ©s (Pan troglodytes), bonobos (Pan paniscus), orangs-outangs (Pongo pygmaeus),gorilles (Gorilla gorilla). LâĂ©tude de la dimension temporelle de lâĂ©change montre que latolĂ©rance au dĂ©lai varie dâune espĂšce Ă lâautre. Pour une rĂ©compense huit fois supĂ©rieure Ă lâitem initial, le dĂ©lai moyen tolĂ©rĂ© est Ă©quivalent Ă 10-20 s pour les capucins, 40-80 s pour lesmacaques, et 1-2 mn pour les chimpanzĂ©s. Chez toutes les espĂšces, la dĂ©cision de la majoritĂ©des individus se rĂ©alise sur la base de mĂ©canismes comme lâestimation de la valeur des biensĂ©changĂ©s et lâanticipation du dĂ©lai d'attente. LâĂ©tude de la prise de risque dans lâĂ©changemontre que la majoritĂ© des orangs-outangs et des capucins nâĂ©changent que lorsque la chancede gagner est supĂ©rieure Ă la chance de perdre. La majoritĂ© des macaques Ă longue queueĂ©change mĂȘme si la chance de gagner est infĂ©rieure Ă la chance de perdre. Les sujets sontcapables dâestimer les probabilitĂ©s de gain et de perte et de prendre en considĂ©ration cesinformations pour dĂ©cider de sâengager ou non dans lâĂ©change. LâĂ©tude de la rĂ©ciprocitĂ© danslâĂ©change rĂ©vĂšle que seuls deux orangs-outangs ont Ă©tĂ© capables de sâengager dans unsystĂšme dâĂ©change stable et calculĂ©. Contrairement aux orangs-outangs, seuls quelques cas dequĂ©mandes et de dons ont Ă©tĂ© relevĂ©s chez les chimpanzĂ©s, les bonobos et les gorilles ; et lesindividus nâont pas Ă©tĂ© capables dâĂ©changer des biens de maniĂšre rĂ©ciproque. Chez lesmacaques et les capucins, aucun cas de quĂ©mande ou de don nâa Ă©tĂ© observĂ©. Bien quel'Ă©change spontanĂ© de biens s'avĂšre difficile chez les primates non humains, ce travail montrequ'ils possĂšdent Ă des degrĂ©s divers les facultĂ©s nĂ©cessaires pour comparer la valeur des biens,accepter un risque de perte ou retarder une gratification, qui sont autant de mĂ©canismes Ă labase des transactions Ă©conomiques chez l'ĂȘtre humain
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