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Widespread niche convergence suggests that species can be organized according to functional trait combinations to create a framework analogous to a periodic table. We compiled ecological data for lizards to examine patterns of global and regional niche diversification, and we used multivariate statistical approaches to develop the beginnings for a periodic table of niches. Data (50+ variables) for five major niche dimensions (habitat, diet, life history, metabolism, defense) were compiled for 134 species of lizards representing 24 of the 38 extant families. Principal coordinates analyses were performed on niche dimensional data sets, and species scores for the first three axes were used as input for a principal components analysis to ordinate species in continuous niche space and for a regression tree analysis to separate species into discrete niche categories. Three-dimensional models facilitate exploration of species positions in relation to major gradients within the niche hypervolume. The first gradient loads on body size, foraging mode, and clutch size. The second was influenced by metabolism and terrestrial versus arboreal microhabitat. The third was influenced by activity time, life history, and diet. Natural dichotomies are activity time, foraging mode, parity mode, and habitat. Regression tree analysis identified 103 cases of extreme niche conservatism within clades and 100 convergences between clades. Extending this approach to other taxa should lead to a wider understanding of niche evolution.

Abstract Critical mitochondrial functions, including cellular respiration, rely on frequently interacting components expressed from both the mitochondrial and nuclear genomes. The fitness of eukaryotic organisms depends on a tight collaboration between both genomes. In the face of an elevated rate of evolution in mtDNA, current models predict that the maintenance of mitonuclear compatibility relies on compensatory evolution of the nuclear genome. Mitonuclear interactions would therefore exert an influence on evolutionary trajectories. One prediction from this model is that the same nuclear genome evolving with different mitochondrial haplotypes would follow distinct molecular paths toward higher fitness. To test this prediction, we submitted 1,344 populations derived from 7 mitonuclear genotypes of Saccharomyces cerevisiae to >300 generations of experimental evolution in conditions that either select for a mitochondrial function or do not strictly require respiration for survival. Performing high-throughput phenotyping and whole-genome sequencing on independently evolved individuals, we identified numerous examples of gene-level evolutionary convergence among populations with the same mitonuclear background. Phenotypic and genotypic data on strains derived from this evolution experiment identify the nuclear genome and the environment as the main determinants of evolutionary divergence, but also show a modulating role for the mitochondrial genome exerted both directly and via interactions with the two other components. We finally recapitulated a subset of prominent loss-of-function alleles in the ancestral backgrounds and confirmed a generalized pattern of mitonuclear-specific and highly epistatic fitness effects. Together, these results demonstrate how mitonuclear interactions can dictate evolutionary divergence of populations with identical starting nuclear genotypes.

This paper suggests day-ahead scheduling of microgrid with and without demand side management considering hydrogen storage and plug-in electric vehicles. This is a highly constrained mixed integer nonlinear programming problem which is solved by using quasi-oppositional fast convergence evolutionary programming (QOFCEP) technique. The concept of the quasi-opposition-based learning is incorporated in fast convergence evolutionary programming (FCEP) to improve the efficiency and quality of the solution. QOFCEP employs quasi-oppositional based learning (QOBL) for population initialization and generation jumping. The studied microgrid comprises three diesel generators, one mini-hydro power plant, two wind turbine generators, two solar PV plants, one hydrogen storage system and plug-in electric vehicles. Simulation outcomes of the suggested QOFCEP technique have been compared with those obtained by FCEP and differential evolution (DE). It is seen from numerical results that the cost obtained with DSM is about 0.81% lower than the cost obtained without DSM. It is also seen that the cost obtained from QOFCEP is about 0.52% and 0.78% lower than the cost obtained from FCEP and DE, respectively. The suggested QOFCEP technique has the ability to bestow superior-quality solution.

In this article, we investigate convergent evolution toward durophagy in carnivoran skull shape using geometric morphometrics in a sample of living and extinct species. Principal components analysis indicate that, in spite of the different dietary resources consumed by durophages—that is, bone-crackers and bamboo-feeders—both groups of carnivorans share portions of skull phenotypic spaces. We identify by discriminant analyses a shared set of adaptations toward durophagy in the skull of carnivores. However, ancestral states indicate that although durophages reached similar phenotypes, the evolutionary pathways that they followed are different depending upon the family to which they belong. Furthermore, while the carnivoran cranium more closely reflects the nature of the resources consumed—that is, soft or hard and tough items—the mandible shows particular feeding adaptations—that is, bamboo or bone. This finding supports the interpretation that the mandible has more evolutionary plasticity than the cranium, which is more limited to evolve toward a particular feeding adaptation. However, we find that the shapes of the cranium and the mandible are highly integrated for the whole order Carnivora. Published studies of teratological cats and dogs indicate that the role of internal constraints in shaping this pattern of integration is absent or weak and malleable by selection.

Background Natural model systems are indispensable for exploring adaptations in response to environmental pressures. Sinocyclocheilus of China, the most diverse cavefish clade in the world (75 species), provide unique opportunities to understand recurrent evolution of stereotypic traits (such as eye loss and sensory expansion) in the context of a deep and diverse phylogenetic group. However, they remain poorly understood in terms of their morphological evolution. Therefore, we explore key patterns of morphological evolution, habitat utilization and geographic distribution in these fishes. Results We constructed phylogenies and categorized 49 species based on eye-related condition (Blind, Micro-eyed, and Normal-eyed), habitat types (Troglobitic—cave-restricted; Troglophilic—cave-associated; Surface—outside caves) and existence of horns. Geometric-morphometric analyses show Normal-eyed morphs with fusiform shapes segregating from Blind/Micro-eyed deeper bodied morphs along the first principal-component axis; second axis accounts for shape complexity related to horns. The body shapes showed a significant association with eye-related condition and horn, but not habitat types. Ancestral reconstructions suggest at least three independent origins of Blind morphs, each with different levels of modification in relation to their ancestral Normal-eyed morphs; Sinocyclocheilus are also pre-adapted for cave dwelling. Our geophylogeny shows an east-to-west diversification spanning Pliocene and Pleistocene, with early-diversifying Troglobitic species dominating subterranean habitats of karstic plains whereas predominantly Surface forms inhabit hills to the west. Evolutionary rates analyses suggest that lineages leading to Blind morphs were characterized by significant rate shifts, such as a slowdown in body size evolution and a 5–20 fold increase in rate of eye regression, possibly explained by limited resource availability. Body size and eye size have undergone reversals, but not horns, a trait entailing considerable time to form. Conclusions Sinocyclocheilus occupied cave habitats in response to drying associated with aridification of China during late Miocene and the Pliocene. The prominent cave-adaptations (eye-regression, horn-evolution) occur in clades associated with the extensive subterranean cave system in Guangxi and Guizhou provinces. Integration of morphology, phylogeny, rate analyses, molecular-dating and distribution show not only several remarkable patterns of evolution, but also interesting exceptions to these patterns signifying the diversification of Sinocyclocheilus as an invaluable model system to explore evolutionary novelty.

Biodiversity refugia formed by unique features of the Mediterranean arid landscape, such as the dramatic ecological contrast of “Evolution Canyon,” provide a natural laboratory in which local adaptations to divergent microclimate conditions can be investigated. Significant insights have been provided by studies of Drosophila melanogaster diversifying along the thermal gradient in Evolution Canyon, but a comparative framework to survey adaptive convergence across sister species at the site has been lacking. To fill this void, we present an analysis of genomic polymorphism and evolutionary divergence of Drosophila simulans, a close relative of Drosophila melanogaster with which it co-occurs on both slopes of the canyon. Our results show even deeper interslope divergence in D. simulans than in D. melanogaster, with extensive signatures of selective sweeps present in flies from both slopes but enhanced in the population from the hotter and drier south-facing slope. Interslope divergence was enriched for genes related to electrochemical balance and transmembrane transport, likely in response to increased selection for dehydration resistance on the hotter slope. Both species shared genomic regions that underwent major selective sweeps, but the overall level of adaptive convergence was low, demonstrating no shortage of alternative genomic solutions to cope with the challenges of the microclimate contrast. Mobile elements were a major source of genetic polymorphism and divergence, affecting all parts of the genome, including coding sequences of mating behavior-related genes.

With 75 known species, the freshwater fish genus Sinocyclocheilus is the largest cavefish radiation in the world and shows multiple adaptations for cave‐dwelling (stygomorphic adaptations), which include a range of traits such as eye degeneration (normal‐eyed, micro‐eyed and eyeless), depigmentation of skin, and in some species, the presence of “horns”. Their behavioural adaptations to subterranean environments, however, are poorly understood. Wall‐following (WF) behaviour, where an organism remains in close contact with the boundary demarcating its habitat when in the dark, is a peculiar behaviour observed in a wide range of animals and is enhanced in cave dwellers. Hence, we hypothesise that wall‐following is also present in Sinocyclocheilus, possibly enhanced in eyeless species compared to eye bearing (normal‐/micro‐eyed species). Using 13 species representative of Sinocyclocheilus radiation and eye morphs, we designed a series of assays, based on pre‐existing methods for Astyanax mexicanus behavioural experiments, to examine wall‐following behaviour under three conditions. Our results indicate that eyeless species exhibit significantly enhanced intensities of WF compared to normal‐eyed species, with micro‐eyed forms demonstrating intermediate intensities in the WF distance. Using a mtDNA based dated phylogeny (chronogram with four clades A–D), we traced the degree of WF of these forms to outline common patterns. We show that the intensity of WF behaviour is higher in the subterranean clades compared to clades dominated by normal‐eyed free‐living species. We also found that eyeless species are highly sensitive to vibrations, whereas normal‐eyed species are the least sensitive. Since WF behaviour is presented to some degree in all Sinocyclocheilus species, and given that these fishes evolved in the late Miocene, we identify this behaviour as being ancestral with WF enhancement related to cave occupation. Results from this diversification‐scale study of cavefish behaviour suggest that enhanced wall‐following behaviour may be a convergent trait across all stygomorphic lineages. Sinocyclocheilus, a genus of 75 species of freshwater cavefish, is an emerging model system in evolutionary studies. We studied a behaviour, called “wall‐following,” where fish stay close to the cave walls in absence of light. We show that eyeless species exhibited heightened wall‐following behaviour compared to their sighted counterparts, with small‐eyed species falling in between. We also mapped this behaviour on a phylogenetic tree, discovering a pattern where cave‐dwelling clades showed stronger wall‐following than free‐living ones. Wall‐following is prevalent in all Sinocyclocheilus species and, given the evolutionary history of the genus, is considered an ancestral behaviour that intensified with cave adaptation.

Animal collective behaviors give rise to various spatial patterns, such as the nests of social insects. These structures are built by individuals following a simple set of rules, slightly varying within and among species, to produce a large diversity of shapes. However, little is known about the origin and evolution of the behavioral mechanisms regulating nest structures. In this study, we discuss the perspective of inferring the evolution of collective behaviors behind pattern formations using a phylogenetic framework. We review the collective behaviors that can be described by a single set of behavioral rules, and for which variations of the environmental and behavioral parameter values produce diverse patterns. We propose that this mechanism could be at the origin of the pattern diversity observed among related species, and that, when they are placed in the proper conditions, species have the behavioral potential to form patterns observed in related species. The comparative analysis of shelter tube construction by lower termites is consistent with this hypothesis. Although the use of shelter tubes in natural conditions is variable among species, most modern species have the potential to build them, suggesting that the behavioral rules for shelter tube construction evolved once in the common ancestor of modern termites. Our study emphasizes that comparative studies of behavioral rules have the potential to shed light on the evolution of collective behaviors. Understanding the origin of complex traits has been one of the primary focuses of evolutionary biologists since Darwin. One such trait is the nest structure of social insects, which is built by individuals following a simple set of behavioral rules. Here, we review the litterature on termite nest constructions in a phylogenetic framework and propose that parameter tuning of a common set of behavioral rules is at the origin of the diversity of nest shapes. Our reconstruction of the evolution of termite shelter tube constructions supports this idea, suggesting that the ability to build shelter tubes, and thus the behavioral rules used by termites to build them, originated once in the common ancestor of modern termites.

Collective behaviors in biological systems such as coordinated movements have important ecological and evolutionary consequences. While many studies examine within‐species variation in collective behavior, explicit comparisons between functionally similar species from different taxonomic groups are rare. Therefore, a fundamental question remains: how do collective behaviors compare between taxa with morphological and physiological convergence, and how might this relate to functional ecology and niche partitioning? We examined the collective motion of two ecologically similar species from unrelated clades that have competed for pelagic predatory niches for over 500 million years—California market squid, Doryteuthis opalescens (Mollusca) and Pacific sardine, Sardinops sagax (Chordata). We (1) found similarities in how groups of individuals from each species collectively aligned, measured by angular deviation, the difference between individual orientation and average group heading. We also (2) show that conspecific attraction, which we approximated using nearest neighbor distance, was greater in sardine than squid. Finally, we (3) found that individuals of each species explicitly matched the orientation of groupmates, but that these matching responses were less rapid in squid than sardine. Based on these results, we hypothesize that information sharing is a comparably important function of social grouping for both taxa. On the other hand, some capabilities, including hydrodynamically conferred energy savings and defense against predators, could stem from taxon‐specific biology.

Behavioural synchronization in dogs has been examined separately at intraspecific and interspecific levels. This study is the first to compare dogs’ behavioural synchronization and gaze behaviour when with a familiar person (with FP) compared to a familiar dog (with FD), while walking in an outdoor environment. Twenty dogs were observed under the two experimental conditions. We hypothesized that dogs would demonstrate stronger location and activity synchronization with an FD than with an FP due to similar locomotor patterns, while showing greater gaze attention towards the FP compared to the FD. Our hypothesis was partially confirmed. The results revealed a significantly shorter distance between dogs and the FD than between dogs and the FP. Dogs exhibited a smaller speed difference with the FD than with the FP, but only if they did not cohabit with other dogs. No significant differences were observed in body alignment or gaze behaviour between the two experimental conditions. Our results point to behavioural synchronization as a new instance of evolutionary convergence, as well as daily experiences, here cohabiting with other dogs, as a factor influencing dogs’ ability to synchronize with individuals from different species. This study enhances our understanding of canine cognition in conspecific versus heterospecific contexts.