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135 results for “correlated evolution”
Evolution in alternating environments with tunable inter-landscape correlations
<p>Natural populations are often exposed to temporally varying environments. Evolutionary dynamics in varying environments have been extensively studied, though understanding the effects of varying selection pressures remains challenging. Here we investigate how cycling between a pair of statistically related fitness landscapes affects the evolved fitness of an asexually reproducing population. We construct pairs of fitness landscapes that share global fitness features but are correlated with one another in a tunable way, resulting in landscape pairs with specific correlations. We find that switching between these landscape pairs, depending on the ruggedness of the landscape and the inter-landscape correlation, can either increase or decrease steady-state fitness relative to evolution in single environments. In addition, we show that switching between rugged landscapes often selects for increased fitness in both landscapes, even in situations where the landscapes themselves are anti-correlated. We demonstrate that positively correlated landscapes often possess a shared maximum in both landscapes that allows the population to step through sub-optimal local fitness maxima that often trap single landscape evolution trajectories. Finally, we demonstrate that switching between anti-correlated paired landscapes leads to ergodic-like dynamics where each genotype is populated with nonzero probability, dramatically lowering the steady-state fitness in comparison to single landscape evolution.</p>
Macroevolution of flower color patterning: biased transition rates and correlated evolution with flower size
<p>Floral pigmentation patterns can both mediate plant-pollinator interactions and modify the abiotic environment of reproductive structures. To date there have been no inquiries into the rate and directionality of macroevolutionary transitions between patterned and non-patterned petals despite their ecological importance and ubiquity across angiosperms. Petals in the Potentilleae tribe (Rosaceae) display color patterns in the ultraviolet (UV) and human-visible spectrum, or can be uniform in color (i.e., patternless). Using a phylogeny of Potentilleae, I test whether evolutionary transition rates between patterned and non-patterned petals are biased in either direction. I then examine whether UV and human-visible patterns are phylogenetically correlated and test the prediction that color patterns will evolve in concert with larger flowers if they function as guides to orient pollinators to floral rewards. I found that transition rates were biased toward petals that were uniform in color. Transition rates from patterned to uniformly-colored petals were two and six times higher than the reverse for UV and human-visible pattern, respectively. The presence of UV and human-visible pattern evolved independently from one another. However, the evolution of human-visible pattern was associated with the evolution of larger flowers but the evolution of UV pattern was correlated with the evolution of smaller flowers. I posit that the transition bias towards non-patterned flowers may reflect developmental constraints on spatial regulation of pigments required to produce floral color patterning. The correlated evolution of larger flowers and human-visible pigmentation patterns support the hypothesis that nectar or pollen guides are more likely to evolve in larger-flowered species. This work provides insight into how transition rate bias and trait correlations can shape phylogenetic patterns of floral color pattern diversity.</p>
Data from: Impacts of genetic correlation on the independent evolution of body mass and skeletal size in mammals
Mammals show a predictable scaling relationship between limb bone size and body mass. This relationship has a genetic basis which likely evolved via natural selection but it is unclear how much the genetic correlation between these traits in turn impacts their capacity to evolve independently. We selectively bred laboratory mice for increases in tibia length independent of body mass to test the hypothesis that a genetic correlation with body mass constrains evolutionary change in tibia length. Over 14 generations we produced mean tibia length increases of 11-12% while mean body mass was unchanged in selectively bred mice and random-bred controls. Using evolutionary scenarios with different selection and quantitative genetic parameters we also found that this genetic correlation impedes the rate of evolutionary change in both traits slowing increases in tibia length while preventing decreases in body mass despite the latter's negative effect on fitness. Overall results from this ongoing selection experiment suggest that parallel evolution of relatively longer hind limbs among rodents for example in the context of strong competition for resources and niche partitioning in heterogeneous environments may have occurred very rapidly on geological timescales in spite of the genetic correlation between tibia length and body mass.
Data from: Evolutionary history and genetic parallelism affect correlated responses to evolution
We investigated the relationship between genomic and phenotypic evolution among replicate populations of Escherichia coli evolved for 1000 generations in four different environments. By re-sequencing evolved genomes, we identified parallel changes in genes encoding transcription regulators within and between environments. Depending on both the environment and the altered gene, genetic parallelism at the gene level involved mutations that either repeatedly affected identical codons or domains or were more widely distributed within the relevant genes. Evolved clones were characterized by parallel phenotypic changes in their respective evolution environments but also in the three alternative environments. Phenotypic parallelism for both traits was high for clones that evolved in the same environment, even in the absence of genetic parallelism. By contrast, clones that evolved in different environments revealed a higher parallelism in correlated responses when they shared mutated genes. Altogether, this work shows that after an environmental change or the colonization of a new habitat, similar ecological performances might be expected for individuals that shared mutated genes or experienced similar past selective pressures.
Data from: Selection on learning performance results in the correlated evolution of sexual dimorphism in life history
The evolution of learning can be constrained by trade-offs. As male and female life-histories often diverge, the relationship between learning and fitness may differ between the sexes. However, because sexes share much of their genome, intersexual genetic correlations can prevent males and females from reaching their sex-specific optima resulting in intralocus sexual conflict (IaSC). To investigate if IaSC constraints sex-specific evolution of learning we selected Caenorhabditis remanei nematode females for increased or decreased olfactory learning performance and measured learning, lifespan (in mated and virgin worms), reproduction and locomotory activity in both sexes. Males from downward-selected female lines had higher locomotory activity and longer virgin lifespan but sired fewer progeny than males from upward-selected female lines. In contrast, we found no effect of selection on female reproduction and downward-selected females showed higher locomotory activity but lived shorter as virgins than upward-selected females. Strikingly, selection on learning performance led to the reversal of sexual dimorphism in virgin lifespan. We thus show sex-specific trade-offs between learning, reproduction and lifespan. Our results support the hypothesis that selection on learning performance can shape the evolution of sexually dimorphic life-histories via sex-specific genetic correlations.
Data from: Data set incongruence and correlated character evolution: an example of functional convergence in the hind-limbs of stifftail diving ducks
The unwitting inclusion of convergent characters in phylogenetic estimates poses a serious problem for efforts to recover phylogeny. Convergence is not inscrutable, however, particularly when one group of characters tracks phylogeny and another set tracks adaptive history. In such cases, convergent characters may be correlated with one or a few functional anatomical units and readily identifiable using comparative methods. Stifftail ducks (Oxyurinae) offer one such opportunity to study correlated character evolution and function in the context of phylogenetic reconstruction. Morphological analyses place stifftail ducks as part of a large clade of diving ducks that includes the sea ducks (Mergini), Hymenolaimus, Merganetta, and Tachyeres, and possibly the pochards (Aythyini). Molecular analyses, on the other hand, place stifftails far from other diving ducks and suggest, moreover, that stifftails are polyphyletic. Mitochondrial cytochrome b gene sequences of eight stifftail species traditionally supposed to form a clade were compared with each other and with sequences from 50 other anseriform and galliform species. Stifftail ducks are not the sister group of sea ducks, but lie outside the typical ducks (Anatinae). Of the four traditional stifftail genera, monophyly of Oxyura and its sister group relationship with Nomonyx are strongly supported. Heteronetta probably is the sister group of that clade, but support is weak. Biziura is not a true stifftail. Within Oxyura, Old World species (O. australis, O. leucocephala, O. maccoa) appear to form a clade, with New World species (O. jamaicensis, O. vittata) branching basally. Incongruence between molecules and morphology is interpreted to be the result of adaptive specialization and functional convergence in the hind limbs of Biziura and true stifftails. When morphological characters are divided into classes, only hind-limb characters are significantly in conflict with the molecular tree. Null models of synonomous and nonsynonomous substitution based on patterns of codon-degeneracy and chemical dissimilarity, likewise, indicate that the nucleotide and amino acid changes postulated by the molecular tree are more plausible than those postulated by the morphological tree. These findings teach general lessons about the utility of highly adaptive characters (in particular those related to foraging ecology) and underscore the problems that convergence can pose for attempts to recover phylogeny. They also demonstrate how the concept of natural data partitions and simple models of evolution (e.g., parsimony, likelihood, neutrality) can be used to test the accuracy of independent phylogenetic estimates and provide arguments in favor of one tree topology over another.
Data from: Correlated evolution of senescence and ephemeral substrate use in the Sordariomycetes
Evolutionary theory predicts that senescence – a decline in reproduction and survival with increasing age - can evolve as a trade-off between the investment in reproduction on one side and in somatic maintenance and repair on the other side. The ecology of a species is crucial here, since it provides the external causes of death that determine the statistical limit to a species' lifespan. Filamentous fungi are generally believed to be non-senescent, and there are indeed spectacular examples of very old fungal individuals in nature. Yet, for some fungi the growth conditions are ephemeral and therefore senescence is expected to have evolved, like in the coprophilic Podospora anserina, the only well-studied filamentous fungus with intrinsic senescence. Here we hypothesize that rapid senescence is more common in fungi than generally believed and that the phylogenetic distribution of senescence correlates with its ecology. We examined a set of Sordariomycetes for their lifespan and constructed phylogenies based on several nuclear sequences. Part of the strains were from the CBS culture collection, originally isolated from various substrates, some of which ephemeral. In addition we isolated new strains from short-lived substrates. Senescence was observed throughout the phylogeny. Correlation tests support the hypothesis that in the Sordariomycetes senescence is a trait that has arisen as an evolved adaptation to ephemeral substrates, and that it has evolved repeatedly and independently along the phylogeny.
Fruit syndromes in Viburnum: correlated evolution of color, nutritional content, and morphology in bird-dispersed fleshy fruits
<p>Premise</p> <p>A key question in plant dispersal via animal vectors is where and why fruit colors vary between species and how color relates to other fruit traits. To better understand the factors shaping the evolution of fruit color diversity, we tested for the existence of syndromes of traits (color, morphology, and nutrition) in the fruits of Viburnum. We placed these results in a larger phylogenetic context and reconstructed ancestral states to assess how Viburnum fruit traits have evolved across the clade.</p> <p>Results</p> <p>We find that blue Viburnum fruits are not very juicy, have high lipid content, and large, round endocarps surrounded by a small quantity of pulp. Red fruits display the opposite suite of traits: they are very juicy with low lipid content and smaller, flatter endocarps. The ancestral Viburnum fruit may have gone through a sequence of color changes before maturation (green to yellow to red to black), though our reconstructions are equivocal. In one major clade of Viburnum (Nectarotinus), fruits mature synchronously with reduced intermediate color stages. Most transitions between fruit colors occurred in this synchronously fruiting clade.</p> <p>Conclusions</p> <p>It is widely accepted that fruit trait diversity has primarily been driven by the differing perceptual abilities of bird versus mammal frugivores. Yet within a clade of largely bird-dispersed fruits, we find clear correlations between color, morphology, and nutrition. These correlations are likely driven by a shift from sequential to synchronous development, followed by diversification in color, nutrition, and morphology. A deeper understanding of fruit evolution within clades will elucidate the degree to which such syndromes structure extant fruit diversity.</p>
Data from: Correlated evolution of body and fin morphology in the cichlid fishes
Body and fin shape are chief determinants of swimming performance in fishes. Different configurations of body and fin shape can suit different locomotor specializations. The success of any configuration is dependent upon the hydrodynamic interactions between body and fins. Despite the importance of body-fin interactions for swimming, there are few data indicating whether body and fin configurations evolve in concert, or whether these structures vary independently. The cichlid fishes are a diverse family whose well-studied phylogenetic relationships make them ideal for the study of macroevolution of ecomorphology. This study measured body, caudal and median fin morphology from radiographs of 131 cichlid genera, using morphometrics and phylogenetic comparative methods to determine whether these traits exhibit correlated evolution. Partial least squares canonical analysis revealed that body, caudal fin, dorsal fin, and anal fin shapes all exhibited strong correlated evolution consistent with locomotor ecomorphology. Major patterns included the evolution of deep body profiles with long fins, suggestive of maneuvering specialization; and the evolution of narrow, elongate caudal peduncles with concave tails, a combination that characterizes economical cruisers. These results demonstrate that body shape evolution does not occur independently of other traits, but among a suite of other morphological changes that augment locomotor specialization.
Data from: Evolution of pre- and post-copulatory traits in male Drosophila melanogaster as a correlated response to selection for resistance to cold stress
Background: In Drosophila melanogaster the fitness of males depends on a broad array of reproductive traits classified as pre- and post-copulatory traits. Exposure to cold stress, can reduce sperm number, male mating ability and courtship behavior. Therefore, it is expected that the adaptation to cold stress will involve changes in pre- and post-copulatory traits. Such evolution of reproductive traits in response to cold stress is not well studied. Methods: We selected replicate populations of D. melanogaster for resistance to cold shock. Over 37–46 generations of selection, we investigated pre- and post-copulatory traits such as mating latency, copulation duration, mating frequency, male fertility, fitness (progeny production) and sperm competitive ability in male flies subjected to cold shock and those not subjected to cold shock. Results: We found that post cold shock, the males from the selected populations had a significantly lower mating latency along with, higher mating frequency, fertility, sperm competitive ability and number of progeny relative to the control populations. Conclusion: While most studies of experimental evolution of cold stress resistance have documented the evolution of survivorship in response to selection, our study clearly shows that adaptation to cold stress involves rapid changes in the pre- and post-copulatory traits. Additionally, improved performances under stressful conditions need not necessarily trade-off with performance under benign conditions.
Data from: Changing the habitat: the evolution of inter-correlated traits to escape from predators
Burst escape speed is an effective and widely used behaviour for evading predators, with burst escape speed relying on several different morphological features. However, we know little about how behavioural and underlying morphological attributes change in concert as a response to changes in selective predation regime. We studied inter-correlated trait differentiation of body shape and burst-swim-mediating morphology in response to a habitat shift related reduction in burst escape speed using larvae of the dragonfly genus Leucorrhinia. Species in this genus underwent a well-known habitat shift from predatory fish lakes (fish-lakes) to predatory fish free lakes dominated by large predatory dragonflies (dragonfly-lakes) accompanied by relaxed selection on escape burst speed. Results revealed that species from fish-lakes that possess faster burst speed have evolved a suite of functionally inter-correlated traits, expressing a wider abdomen, a higher abdominal muscles mass and a larger branchial chamber compared to species from dragonfly-lakes. In contrast, populations within species did not show significant differences in muscle mass and branchial chamber size between lakes types in three of the species. High multi-collinearity among variables suggests that traits have evolved in concert rather than independently when Leucorrhinia shifted from fish lakes to dragonfly lakes. Thus, relaxed selection on burst escape speed in dragonfly-lake species resulted in a correlated reduction of abdominal muscles and a smaller branchial chamber, likely to save production and/or maintenance costs. Our results highlight the importance of studying integrated behavioural and morphological traits to fully understand the evolution of complex phenotypes.
Data from: Rates of morphological evolution are correlated with species richness in salamanders
The tempo and mode of species diversification and phenotypic evolution vary widely across the tree of life, yet the relationship between these processes is poorly known. Previous tests of the relationship between rates of phenotypic evolution and rates of species diversification have assumed that species richness increases continuously through time. If this assumption is violated, simple phylogenetic estimates of net diversification rate may bear no relationship to processes that influence the distribution of species richness among clades. Here we demonstrate that the variation in species richness among plethodontid salamander clades is unlikely to have resulted from simple time-dependent processes, leading to fundamentally different conclusions about the relationship between rates of phenotypic evolution and species diversification. Morphological evolutionary rates of both size and shape evolution are correlated with clade species richness, but are uncorrelated with simple estimators of net diversification that assume constancy of rates through time. This coupling between species diversification and phenotypic evolution is consistent with the hypothesis that clades with high rates of morphological trait evolution may diversify more than clades with low rates. Our results indicate that assumptions about underlying processes of diversity regulation have important consequences for interpreting macroevolutionary patterns.
Data from: Correlated evolution of sexual dimorphism and male dimorphism in a clade of neotropical harvestmen
Secondary sexual traits increase male fitness, but may be maladaptive in females, generating intralocus sexual conflict that is ameliorated through sexual dimorphism. Sexual selection on males may also lead some males to avoid expenditure on secondary sexual traits and achieve copulations using alternative reproductive tactics (ARTs). Secondary sexual traits can increase or decrease fitness in males, depending on which ART they employ, generating intralocus tactical conflict that can be ameliorated through male dimorphism. Due to the evolutionary forces acting against intralocus sexual and tactical conflicts, male dimorphism could coevolve with sexual dimorphism, a hypothesis that we tested by investigating these dimorphisms across 48 harvestman species. Using three independently derived phylogenies we consistently found that the evolution of sexual dimorphism was correlated with that of male dimorphism, and suggest that the major force behind this relationship is the similarity between selection against intralocus sexual conflict and selection against intralocus tactical conflict. We also found that transitions in male dimorphism were more likely in the presence of sexual dimorphism, indicating that if a sexually selected trait arises on an autosome and is expressed in both sexes, its suppression in females probably evolves earlier than its suppression in small males that adopt ARTs.
Data from: The evolution of defense mechanisms correlate with the explosive diversification of autodigesting Coprinellus mushrooms (Agaricales, Fungi)
Bursts of diversification are known to have contributed significantly to the extant morphological and species diversity, but evidence for many of the theoretical predictions about adaptive radiations have remained contentious. Despite their tremendous diversity, patterns of evolutionary diversification and the contribution of explosive episodes in fungi are largely unknown. Here, using the genus Coprinellus (Psathyrellaceae, Agaricales) as a model, we report the first explosive fungal radiation, and infer that the onset of the radiation follows a change from a multi-layered to a much simpler defense structure on the fruiting bodies. We suggest that this change constitutes a key innovation, relaxing constraints on diversification imposed by nutritional investment into the development of protective tissues of fruiting bodies. Evidence for the impact of protective structures on diversification places our current understanding of fruiting body evolution in a new context. Fossil calibration suggests that Coprinellus mushrooms radiated during the Miocene coinciding with global radiation of large grazing mammals following expansion of dry open grasslands. In addition to diversification-rate based methods, we test the hard polytomy hypothesis, by analyzing the resolvability of internal nodes of the backbone of the putative radiation using Reversible-Jump MCMC. We discuss potential applications and pitfalls as well as how biologically meaningful polytomies can be distinguished from alignment shortcomings. Our data provide insights into the nature of adaptive radiations in general by revealing a deceleration of morphological diversification through time. The "rate" of morphological diversification was approximated by obtaining the temporal distribution of state changes in discrete traits along the trees and comparing it with the tempo of lineage accumulation. By using speciational trees, we found that the number of state changes correlate with the number of lineages, even in parts of the tree with short internal branches, and peaks around the onset of the explosive radiation followed by a slowdown, most likely because of the decrease in available niches.
Data from: Widespread correlations between climatic niche evolution and species diversification in birds
The adaptability of species' climatic niches can influence the dynamics of colonisation and gene flow across climatic gradients, potentially increasing the likelihood of speciation, or reducing extinction in the face of environmental change. However, previous comparative studies have tested these ideas using geographically, taxonomically and ecologically restricted samples, yielding mixed results, and thus the processes linking climatic niche evolution with diversification remain poorly understood. Focusing on birds, the largest and most widespread class of terrestrial vertebrates, we test whether variation in species diversification among clades is correlated with rates of climatic niche evolution, and the extent to which these patterns are modified by underlying gradients in biogeography and species' ecology. We quantified climatic niches, latitudinal distribution and ecological traits for 7657 (~75%) bird species based on geographical range polygons, and then used Bayesian phylogenetic analyses to test whether niche evolution was related to species richness and rates of diversification across genus and family-level clades. We found that the rate of climatic niche evolution has a positive linear relationship with both species richness and diversification rate at two different taxonomic levels (genus and family). Furthermore, this positive association between labile climatic niches and diversification was detected regardless of variation in clade latitude or key ecological traits. Our findings suggest either that rapid adaptation to unoccupied areas of climatic niche space promotes avian diversification, or that diversification promotes adaptation. Either way, we propose that climatic niche evolution is a fundamental process regulating the link between climate and biodiversity at global scales, irrespective of the geographical and ecological context of speciation and extinction.
Data from: Adaptive and non-adaptive evolution of trait means and genetic trait correlations for herbivory resistance and performance in an invasive plant
The EICA-hypothesis predicts that invading plants adapt to their novel environment by evolving increased performance and reduced resistance in response to the release from natural enemies, and assumes a resource allocation tradeoff among both trait groups as mechanistic basis of this evolutionary change. Using the plant Silene latifolia as a study system, we tested these predictions by investigating whether 1) invasive populations evolved lower resistance and higher performance, 2) this evolutionary change is indeed adaptive, and 3) there is a negative genetic correlation among performance and resistance (i.e. a tradeoff) in native and introduced individuals. We sampled eight native and eight invasive populations and determined their population co-ancestry based on neutral SSR-markers. We performed controlled crossings to produce five sib-groups per population and exposed them to increased and reduced levels of enemy attack in a full-factorial experiment to estimate performance and resistance. With these data, we performed trait-by-trait comparisons between ranges with 'animal models' that account for population co-ancestry to quantify the amount of variance in traits explained by non-adaptive vs. adaptive evolution. Moreover, we tested for genetic correlations among performance and resistance traits within sib-groups. We found significant reductions in resistance and increases in performance in invasive versus native populations, which could largely be attributed to adaptive evolution. While we detected a non-significant trend towards negative genetic performance × resistance correlations in native populations, invasive populations exhibited both significant and non-significant positive correlations. In summary, these results do not support a shift of performance and resistance trait values along a tradeoff line in response to enemy release, as predicted EICA. They rather suggest that the independent evolution of both traits is not constrained by a tradeoff, and that various selective agents (including resource availability) interact in shaping both traits and in weakening negative genetic correlations in the invaded habitat.
Data from: Antibiotic resistance correlates with transmission in plasmid evolution
Conjugative (horizontally transmissible) plasmids are autonomous replicators, whose 'self-interests' do not necessarily overlap with those of their hosts. This situation causes plasmids and bacteria to sometimes experience differing selection pressures. Escherichia coli plasmid pB15 contains genes for resistance to several antibiotics, including tetracycline. When plasmid-bearing cells were experimentally evolved in the laboratory, changes in resistance level in the unselected tetracycline marker coincided with changes in plasmid rates of vertical versus horizontal transmission. Here we used minimum-inhibitory assays that measure resistance levels as quantitative traits to determine phenotypic correlations among plasmid characters and to estimate divergence among plasmid lineages. Results suggested that plasmid-level evolution led to formation of two phenotypically-dissimilar groups: virulent (highly infectious) and avirulent (weakly infectious) plasmids. In contrast, measures of carbon-source utilization, and fitness assays relative to a common competitor revealed that bacterial hosts generally converged in phenotypic performance, despite divergence among their associated plasmids. Preliminary sequence analyses suggested that divergence in plasmid conjugation was due to altered configurations of a shufflon region (a site-specific recombination system), where genetic rearrangements affect conjugative ability. Furthermore, we proposed that correlated resistance and transmission in pB15 derivatives were caused by a tetracycline-resistance transposon inserted into a transfer operon, allowing transcription from its promoter to simultaneously affect both plasmid resistance and transmission.
Data and Code Files for Dalponti et al. Climate Affects the Correlated Evolution of Body Size and Trophic Position in Fishes
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Data from: The experimental evolution of herbicide-resistance in Chlamydomonas reinhardtii results in a positive correlation between fitness in the presence and absence of herbicides
Pleiotropic fitness trade-offs will be key determinants of the evolutionary dynamics of selection for pesticide resistance. However, for herbicide resistance, empirical support for a fitness cost of resistance is mixed, and it is therefore also questionable what further ecological trade-offs can be assumed to apply to herbicide resistance. Here, we test the existence of trade-offs by experimentally evolving herbicide resistance in Chlamydomonas reinhardtii. Although fitness costs are detected for all herbicides, we find that, counterintuitively, the most resistant populations also have the lowest fitness costs as measured by growth rate in the ancestral environment. Furthermore, after controlling for differences in the evolutionary dynamics of resistance to different herbicides, we also detect significant positive correlations between resistance, fitness in the ancestral environment and cross-resistance to other herbicides. We attribute this to the highest levels of nontarget-site resistance being achieved by fixing mutations that more broadly affect cellular physiology, which results in both more cross-resistance and less overall antagonistic pleiotropy on maximum growth rate. Consequently, the lack of classical ecological trade-offs could present a major challenge for herbicide resistance management.
Data from: The correlated evolution of antipredator defences and brain size in mammals
Mammals that possess elaborate antipredator defences such as body armour, spines and quills are usually well protected, intermediate in size, primarily insectivorous and live in simple open environments. The benefits of such defences seem clear and may relax selection on maintaining cognitive abilities that aid in vigilance and predator recognition, and their bearers may accrue extensive production and maintenance costs. Here, in this comparative phylogenetic analysis of measurements of encephalization quotient and morphological defence scores of 647 mammal species representing nearly every order, we found that as lineages evolve stronger defences, they suffer a correlated reduction in encephalization. The only exceptions were those that live in trees—a complex three-dimensional world probably requiring greater cognitive abilities. At the proximate level, because brain tissue is extremely energetically expensive to build, mammals may be trading off spending more on elaborate defences and saving by building less powerful brains. At the ultimate level, having greater defences may also reduce the need for advanced cognitive abilities for constant assessment of environmental predation risk, especially in simple open environments.
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Allen Brain Atlas
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Annotated Behaviour and Observability Dataset (ABODe)
ABODe is a University of Edinburgh DataShare dataset for behavior classification in group-housed mice using home-cage video, identities, bounding boxes, ground-plate positions, and annotator labels.
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