Biological Rules Research Articles

Context-dependent evolution of ostracod morphology along the ecogeographical gradient of ocean depth.

Ecogeographical rules inform our understanding of biodiversity by seeking reliable associations between organismal phenotypes and environmental factors. Reminiscent of classic ecogeographical rules, environmental factors vary in predictable ways with ocean depth, leading to predictions about organismal phenotypes. A valuable group for studying associations between habitat depth and phenotype is cylindroleberidid ostracods (Crustacea) because of previous phylogenetic analyses and their enormous depth range. Using phylogenetic comparative methods, we asked how habitat depth relates to body size and eye morphology in 232 cylindroleberidid species measured from museum specimens and literature descriptions. For each species, we recorded maximum habitat depth, body size, absolute eye size, number of ommatidia (facets) per eye, and diameter of the largest ommatidium. We find that the relationship between morphology and habitat depth in cylindroleberidids depends on pelagic zone: as depth increases in the photic zone, body size increases and eyes have fewer ommatidia; as depth increases in the disphotic zone, body size does not change and eyes have more ommatidia. We did not find a relationship between absolute eye size and depth in either pelagic zone. Overall, we find that associations between phenotypes and ecogeographical gradients depend on interactions between contexts such as pelagic zone, character state, and evolutionary history.

Clinal variation in morph frequency in Swainson’s hawk across North America: no support for Gloger’s ecogeographical rule

Clinal variation in morph frequency in Swainson’s hawk across North America: no support for Gloger’s ecogeographical rule

Commentary: 'Ready or not here I come': developmental immaturity as a driver of impairment and referral in young-for-school-grade ADHD children. A reformulation inspired by Whitely etal. (2019).

The search for objective biological tests, sufficiently reliable, and predictive enough to be diagnostic of psychiatric disorders, continues apace - yet their discovery remains a distant dream. It seems increasingly unlikely that current diagnostic structures and concepts map biologically in a straight forward way - with heterogeneity within, and sharing across, existing diagnostic boundaries being the biological rule rather than the exception. Indeed, it now appears that the science of biological psychiatry is more likely to redraw those boundaries than it is to confirm and mark them (Sonuga-Barke, Journal of Child Psychology and Psychiatry, 2016, 57, 1). Clinical identification of childhood psychiatric disorders therefore remains, for the foreseeable future at least, an exercise in regulated social perception - reliant on the fallible and subjective judgements of parents, teachers and clinicians. Social perception of this sort is an active and motivated process and therefore prone, like all social perception, to bias and distortions - both systematic and idiosyncratic. Progress has certainly been made over the last 50years in reducing such judgement bias by, for instance filtering perceptions through the lens of standardised instruments (questionnaires and interviews) with carefully operationalised items and a degree of reliability and validity. However, such instruments often play only a peripheral role in actual diagnostic encounters and when they are used, there is still sufficient ambiguity to leave open plenty of room for interpretation. When we acknowledge that psychiatric diagnoses are social constructions - we are not saying that symptoms of inattention, impulsivity and hyperactivity are not real or do not cluster together in meaningful ways or that they do not cause real distress and disability but that their interpretation and meaning are often informed by social constructs such as ethnic or gender norms and stereotypes (Meyer, Stevenson, & Sonuga-Barke, Journal of Attention Disorders, 2019).

A review of Gloger's rule, an ecogeographical rule of colour: definitions, interpretations and evidence

Gloger's rule is an ecogeographical rule that links animal colouration with climatic variation. This rule is named after C.W.L. Gloger who was one of the first to summarise the associations between climatic variation and animal colouration, noting in particular that birds and mammals seemed more pigmented in tropical regions. The term 'Gloger's rule' was coined by B. Rensch in 1929 and included different patterns of variation from those described by Gloger. Rensch defined the rule in two ways: a simple version stating that endothermic animals are predicted to be darker in warmer and humid areas due to the increased deposition of melanin pigments; and a complex version that includes the differential effects of humidity and temperature on both main types of melanin pigments-eu- and phaeo-melanin. The blackish eu-melanins are predicted to increase with humidity, and decrease only at extreme low temperatures, while the brown-yellowish phaeomelanins prevail in dry and warm regions and decrease rapidly with lower temperatures. A survey of the literature indicates that there is considerable variation/confusion in the way Gloger's rule is understood (based on 271 studies that define the rule). Whereas the complex version is hardly mentioned, only a quarter of the definitions are consistent with the simple version of Gloger's rule (darker where warm and wet), and most definitions mention only the effects of humidity (darker where wet). A smaller subset of studies define the rule based on other correlated climatic and environmental variables such as vegetation, latitude, altitude, solar radiation, etc., and a few even contradict the original definition (darker where cold). Based on the literature survey, I synthesised the qualitative (N=124 studies) and quantitative (meta-analytically, N=38 studies, 241 effects) evidence testing the simple version of Gloger's rule (I found no tests of the complex version). Both lines of evidence supported the predicted effects of humidity (and closely linked variables) on colour variation, but not the effects of temperature. Moreover, humidity effects are not restricted to birds and mammals, as the data indicate that these effects also apply to insects. This suggests that the simple version of Gloger's rule as originally defined may not be valid, and possibly that the rule should be re-formulated in terms of humidity effects only. I suggest, however, that more data are needed before such a reformulation, due to potential publication biases. In conclusion, I recommend that authors cite Rensch when referring to Gloger's rule and that they make clear which version they are referring to. Future research should concentrate on rigorously testing the validity and generality of both versions of Gloger's rule and establishing the mechanism(s) responsible for the patterns it describes. Since humidity seems to be the core climatic variable behind Gloger's rule, I suggest that the two most plausible mechanisms are camouflage and protection against parasites/pathogens, the latter possibly through pleiotropic effects on the immune system. Understanding the processes that lead to climatic effects on animal colouration may provide insights into past and future patterns of adaptation to climatic change.

A macroecological approach to evolutionary rescue and adaptation to climate change

Despite the widespread use of ecological niche models (ENMs) for predicting the responses of species to climate change, these models do not explicitly incorporate any population‐level mechanism. On the other hand, mechanistic models adding population processes (e.g. biotic interactions, dispersal and adaptive potential to abiotic conditions) are much more complex and difficult to parameterize, especially if the goal is to predict range shifts for many species simultaneously. In particular, the adaptive potential (based on genetic adaptations, phenotypic plasticity and behavioral adjustments for physiological responses) of local populations has been a less studied mechanism affecting species’ responses to climatic change so far. Here, we discuss and apply an alternative macroecological framework to evaluate the potential role of evolutionary rescue under climate change based on ENMs. We begin by reviewing eco‐evolutionary models that evaluate the maximum sustainable evolutionary rate under a scenario of environmental change, showing how they can be used to understand the impact of temperature change on a Neotropical anuran species, the Schneider's toad Rhinella diptycha. Then we show how to evaluate spatial patterns of species’ geographic range shift using such models, by estimating evolutionary rates at the trailing edge of species distribution estimated by ENMs and by recalculating the relative amount of total range loss under climate change. We show how different models can reduce the expected range loss predicted for the studied species by potential ecophysiological adaptations in some regions of the trailing edge predicted by ENMs. For general applications, we believe that parameters for large numbers of species and populations can be obtained from macroecological generalizations (e.g. allometric equations and ecogeographical rules), so our framework coupling ENMs with eco‐evolutionary models can be applied to achieve a more accurate picture of potential impacts from climate change and other threats to biodiversity.

A CMOS-based Neuron Circuit for Spiking Neural Networks with Memristive Synapse

The brained-inspired spiking neural networks (SNNs), which can be applied on visual information processing and speech recognition, is attracting great attention especially when combined with emerging electronic synapse (i.e. memristor). The neuron, transmitting and receiving spiking signals, is a vital component to realize the biological rules of SNNs, such as leaky-integrate-and-fire (LIF), inhibitory period, winner takes all (WTA) and bidirectional transmission. In this work, we propose and implement a novel spiking neuron circuit based on complementary- metal-oxide-semiconductor (CMOS) technology. Experimental results show that the neuron circuit can generate spiking pulses, realize lateral inhibition and change the weight of synapse.

Acute Pneumonia: Biological Rules and Laws require Attention and Respect.

Acute Pneumonia: Biological Rules and Laws require Attention and Respect.

Ecogeographic patterns in fetal limb proportions.

Humans generally comply with the ecological rule of Allen (1877), with populations from tropical environments exhibiting body proportions in which limb segments are long relative to trunk height compared to temperate groups. This study tests whether ecogeographic differences in intralimb proportions are identifiable among two modern fetal samples of differing ancestry. Data are derived from radiographic measurements of long bone diaphyseal length and crown-heel length (CHL) of contemporary, spontaneously aborted fetuses of African Americans ("black") of assumed African (tropical) ancestry and European Americans ("white") of assumed European (temperate) ancestry (n = 184). Population individual limb elements, brachial, and crural indices are compared via analyses of covariance (ANCOVA). Potential patterns of divergent allometric growth are quantified through principal components analysis (PCA). African ancestral distal limb elements were consistently, albeit slightly, longer than those of European ancestry, relative to CHL. None of the ANCOVA interactions with ancestry are statistically significant for limb indices. The radius was the only single element that displayed a statistically significant ancestry effect (p = 0.0435) equating to a 1 mm difference. PCA highlights that upper limbs demonstrate negative allometry and lower limbs demonstrate positive allometry with sample-specific multivariate growth patterns being nearly identical. Differences in growth allometry late in gestation make little contribution to observed differences in adult limb proportions. No statistically significant ecogeographic patterns were appreciated among intralimb proportions between these groups during the fetal period. This study contributes to a greater appreciation of phenotypic plasticity, ecogeographic variation in ontogeny, and the evolution of modern human diversity.

The impact of proliferation and cancer stem cell upon the resistence to chemotherapy in salivary mucopepidermoid carcinoma

Background and aim: Mucoepidermoid carcinoma is a common salivary tumor that affects both adults and children. Proliferation is one of the most fundamental biological processes of growth and maintenance of tissue homeostasis. CD-44 may be used as an indicator of aggressive behavior of some human malignancy. Multidrug resistance is one of the major obstacles for successful cancer chemotherapy. The present study was carried out for evaluation of the biological rules and the clinicopathological significance of Ki-67, CD-44 and MDR-1 expression in the different histopathological grades of MECs.Patients and methods: Eighty paraffin embedded MEC tissues were collected and classified to three groups according to their histological grades. Tissue sections were stained with Ki-67, CD-44 and MDR-1 then examined microscopically and analyzedstatistically.Result: High grade MEC cases showed the highest expression for Ki-67, CD-44 and MDR-1. Additionally, significant differences were found between the histopathological grades as well as between lymph node stages of the studied cases and the expression of the three utilized markers.Conclusion: Ki-67, CD-44 and MDR-1can be used to evaluate the degree of differentiation and to predict the prognosis of MECs, furthermore, high grade MEC cases with high proliferative indices might be resistant to chemotherapy.

Knitting patterns of biodiversity, range size and body size in aquatic beetle faunas: significant relationships but slightly divergent drivers

1. Ecogeographical rules refer to recurring patterns in nature, including the latitudinal diversity gradient (LDG), Rapoport's rule and Bergmann's rule, amongst others. In the present study, the existence of these rules was examined for diving beetles (Coleoptera: Dytiscidae), a family of aquatic predatory beetles.2. Assemblage‐level data were analysed for diving beetles, focusing on species richness, local contribution to beta diversity (LCBD), mean range size and mean body size across the biogeographical provinces of Northern Europe. First, each of these variables was correlated with latitude, and then variation in each variable was modelled using actual environmental variables in boosted regression tree analysis.3. Species richness was found to decrease with latitude, LCBD increased with latitude, mean range size did not show a significant relationship with latitude, and mean body size decreased with latitude. The latter finding was in contrast to Bergmann's rule. The actual environmental variables best predicting variation in these four response variables varied among the models, although they generally included temperature‐related and land use variables as the most influential ones.4. The results obtained in the present study suggest that diving beetles conformed to the LDG, did not follow Rapoport's rule, and showed a reversed latitudinal gradient in the context of Bergmann's rule. In addition, species‐poor provinces harboured ecologically most unique faunas, suggesting that species richness and LCBD are complementary measures of biodiversity.5. Even though general support was not found for most of the ecogeographical rules examined, the findings of the present study are interesting because they suggest that aquatic ectothermic invertebrates may show patterns different from those originally described for terrestrial endothermic vertebrates.

Визначення стану сформованості екологічної культури в учнів молодших класів з порушеннями інтелекту

Criteria and indicators of the ecological culture formation in primary school students with intellectual disorders are considered. In particular, the following criteria and indicators of ecological culture are analyzed: demand-motivation (the presence of interest in objects of nature); cognitive (possession of mental activity methods in the process of communicating with natural objects and phenomena, the nature of judgments with regard to the main ecological categories); axiological (presence of experiencing (empathy) in the process of interaction with natural phenomena); behavioral (conformity of the student’s behavior in nature with the assimilated ecological norms and rules). The diagnostic methods were selected according to certain criteria, which enabled to establish the state of ecological culture formation in children of the group studied. The degrees of ecological culture formation in primary school students with intellectual disorders are specified: high, medium, low, destructive. It is proved that low and destructive levels prevail in children with intellectual disorders. It is noted that the results of the determination of the state of ecological culture formation indicate that there is an urgent need to determine the pedagogical conditions that are conducive to overcome the existing shortcomings, as well as correct the content, forms and methods of interaction between school and families, and aimed at forming an environmentally appropriate behavior of primary school students, which is expected to be the prospect of further research.

Low-Power (1T1N) Skyrmionic Synapses for Spiking Neuromorphic Systems

In this paper, we propose a “1-transistor 1-nanotrack” (1T1N) synapse based on the movement of magnetic skyrmions using spin-polarized current pulses. The proposed synaptic bit-cell has four terminals and fully decoupled spike transmission and programming paths. With careful tuning of programming parameters, we ensure multi-level non-volatile conductance evolution in the proposed skyrmionic synapse. Through micromagnetic simulations, we studied in detail the impact of the programming conditions (current density and pulse width) on synaptic performance parameters, such as the number of conductance levels and energy per transition. The programming parameters used for all further analysis gave rise to a synapse with 7 distinct conductance states and 1.2 fJ per conductance state transition event. Exploiting bidirectional conductance modulation, the 1T1N synapse is able to undergo long-term potentiation and depression according to a simplified variant of the biological spike timing-dependent plasticity rule. We present a subthreshold CMOS spike generator circuit which when coupled with a well-known subthreshold integrator circuit produces custom pre- and post-neuronal spike shapes responsible for implementing unsupervised learning with the proposed 1T1N synaptic bit-cell and consuming ~0.25 pJ/event. A spiking neural network incorporating the characteristics of the 1T1N synapse was simulated for two separate applications: pattern extraction from noisy video streams and handwritten digit classification.

Golden Orbweavers Ignore Biological Rules: Phylogenomic and Comparative Analyses Unravel a Complex Evolution of Sexual Size Dimorphism.

Instances of sexual size dimorphism (SSD) provide the context for rigorous tests of biological rules of size evolution, such as Cope’s rule (phyletic size increase), Rensch’s rule (allometric patterns of male and female size), as well as male and female body size optima. In certain spider groups, such as the golden orbweavers (Nephilidae), extreme female-biased SSD (eSSD, female:male body length n}{}ge2) is the norm. Nephilid genera construct webs of exaggerated proportions, which can be aerial, arboricolous, or intermediate (hybrid). First, we established the backbone phylogeny of Nephilidae using 367 anchored hybrid enrichment markers, then combined these data with classical markers for a reference species-level phylogeny. Second, we used the phylogeny to test Cope and Rensch’s rules, sex specific size optima, and the coevolution of web size, type, and features with female and male body size and their ratio, SSD. Male, but not female, size increases significantly over time, and refutes Cope’s rule. Allometric analyses reject the converse, Rensch’s rule. Male and female body sizes are uncorrelated. Female size evolution is random, but males evolve toward an optimum size (3.2–4.9 mm). Overall, female body size correlates positively with absolute web size. However, intermediate sized females build the largest webs (of the hybrid type), giant female Nephila and Trichonephila build smaller webs (of the aerial type), and the smallest females build the smallest webs (of the arboricolous type). We propose taxonomic changes based on the criteria of clade age, monophyly and exclusivity, classification information content, and diagnosability. Spider families, as currently defined, tend to be between 37 million years old and 98 million years old, and Nephilidae is estimated at 133 Ma (97–146), thus deserving family status. We, therefore, resurrect the family Nephilidae Simon 1894 that contains Clitaetra Simon 1889, the Cretaceous GeratonephilaPoinar and Buckley (2012), Herennia Thorell 1877, IndoetraKuntner 2006, new rank, Nephila Leach 1815, Nephilengys L. Koch 1872, Nephilingis Kuntner 2013, Palaeonephila Wunderlich 2004 from Tertiary Baltic amber, and TrichonephilaDahl 1911, new rank. We propose the new clade Orbipurae to contain Araneidae Clerck 1757, Phonognathidae Simon 1894, new rank, and Nephilidae. Nephilid female gigantism is a phylogenetically ancient phenotype (over 100 Ma), as is eSSD, though their magnitudes vary by lineage.

An Efficient Motion Generation Method for Redundant Humanoid Robot Arm Based on the Intrinsic Principles of Human Arm Motion

The aim of this paper is trying to propose an efficient method of inverse kinematics and motion generation for redundant humanoid robot arm based on the intrinsic principles of human arm motion. The intrinsic principle analysis takes into account both the skeletal kinematics and muscle strength properties. Firstly, this work analyzed the kinematic redundancy problem of a human arm. By analyzing the biological feature of a human arm, the kinematic redundancy boils down to the uncertainty of elbow position. Secondly, because the muscle’s kinematic and strength properties are critical for simulating biometric motion authentically, the muscle strength property was introduced as the criterion for configuration identification and motion generation. Three types of limb configuration, dog walking, gecko climbing, and human walking limb configuration were analyzed, and two geometrical configuration identification rules were deduced to generate biomimetic motion for humanoid robotic arms. By comparing the proposed method with other five IK methods, the proposed method significantly deduced the computing time. Finally, the configuration identification rules were used to generate motions for a 7-DoF humanoid robotic arm. The results showed that the biological rules can generate biomimetic, smooth arm motions for a redundant humanoid robotic arm.

A two-dimensional (2D) systems biology-based discrete liver tissue model: A simulation study with implications for ultrasound elastography of liver fibrosis

Continuum tissue models that were often used to simulate or analyze the mechanical properties of tissues being imaged may not be biologically realistic. Our primary objective was to establish the feasibility of using systems biology to construct biologically relevant tissue models linking tissue structure, composition and architecture to the ultrasound measurements directly. The first application was designated to model fibrotic liver tissues.The proposed liver tissue model leveraged established histopathology knowledge of fibrotic liver tissues. Particularly, rules of systems biology derived from molecular histopathology were first implemented into an agent-based software platform SPARK to reflect progressions of liver fibrosis with/without steatosis. Then, microscopic compositions of tissues (e.g. cellular components) were converted to computing grids (at the 50–100 μm scale) for wave simulations using an open-source K-Wave. To verify the physical soundness of the proposed model, virtual wave speed measurements (i.e. shear wave speed [SWS] and the speed of sound [SOS]) were performed.Our initial results demonstrated that the simulated SWS values increased with the progression of liver fibrosis (from 1.5 m/s [Fibrosis stage 1] to 4 m/s [Fibrosis stage 4]). Similarly, the simulated SOS values were within the range of clinical data (from 1575 m/s [Fibrosis stage 0–3] to 1594 m/s [Fibrosis stage 4]).In summary, we found that those systems biology simulated fibrotic liver tissues with and without steatosis can reflect spatial characteristics of relevant histology. Also, their mechanical characteristics (i.e. shear/compressional wave speed) were in good agreement with data reported in the clinical literature.

Linking Marine Plankton Ecosystems and Climate: A New Modeling Approach to the Warm Early Eocene Climate

AbstractThe fossil record reveals large changes in marine plankton ecosystems linked with both environmental and ecological change across the Cenozoic. An understanding of the drivers of these changes is key to understanding the marine carbon cycle. The response of plankton ecosystems in past warm climates also provides a key analogue for current climate change. While models are employed to quantify interactions between the environment and the biota, current Earth system models strongly encode our understanding of modern marine ecosystems. By contrast, trait‐based models aim to describe the marine plankton ecosystem in terms of fundamental ecological and physiological rules that are less likely to change through time. This provides a unique opportunity to assess the interactions between marine ecosystem and paleoclimate. For the first time, we apply a size‐structured trait‐based plankton ecosystem model embedded in the Earth system model of intermediate complexity, cGENIE, to model plankton communities for the warm climate of the early Eocene. Compared to modern, we find the warm climate is associated with an increase in the mean cell size of plankton communities and export production, particularly in the southern high latitudes, along with lower total phytoplankton biomass. Paleogeography has an important role in regulating the effect of ecosystem structure via changes in ocean circulation and nutrient cycling. Warmer temperatures also drive changes due to enhanced zooplankton grazing. An integration of the fossil record with plankton ecosystem models will provide a powerful tool to assess the impacts of warm climates on marine systems.

Unsupervised speech recognition through spike-timing-dependent plasticity in a convolutional spiking neural network.

Speech recognition (SR) has been improved significantly by artificial neural networks (ANNs), but ANNs have the drawbacks of biologically implausibility and excessive power consumption because of the nonlocal transfer of real-valued errors and weights. While spiking neural networks (SNNs) have the potential to solve these drawbacks of ANNs due to their efficient spike communication and their natural way to utilize kinds of synaptic plasticity rules found in brain for weight modification. However, existing SNN models for SR either had bad performance, or were trained in biologically implausible ways. In this paper, we present a biologically inspired convolutional SNN model for SR. The network adopts the time-to-first-spike coding scheme for fast and efficient information processing. A biological learning rule, spike-timing-dependent plasticity (STDP), is used to adjust the synaptic weights of convolutional neurons to form receptive fields in an unsupervised way. In the convolutional structure, the strategy of local weight sharing is introduced and could lead to better feature extraction of speech signals than global weight sharing. We first evaluated the SNN model with a linear support vector machine (SVM) on the TIDIGITS dataset and it got the performance of 97.5%, comparable to the best results of ANNs. Deep analysis on network outputs showed that, not only are the output data more linearly separable, but they also have fewer dimensions and become sparse. To further confirm the validity of our model, we trained it on a more difficult recognition task based on the TIMIT dataset, and it got a high performance of 93.8%. Moreover, a linear spike-based classifier—tempotron—can also achieve high accuracies very close to that of SVM on both the two tasks. These demonstrate that an STDP-based convolutional SNN model equipped with local weight sharing and temporal coding is capable of solving the SR task accurately and efficiently.

Do ecogeographical rules explain morphological variation in a diverse, Holarctic genus of small mammals?

AbstractAimWe use ecogeographical rules to understand the relationship between biogeography and morphological evolution in Sorex (Linnaeus, 1758) shrews. Specifically, we test for climatic correlations in body size (Bergmann's rule; larger species in colder habitats) and pelage brightness (Gloger's rule; darker species in more humid/warmer habitats).LocationNorth America and Eurasia (Holarctic).TaxonSorex spp. (Mammalia: Soricomorpha: Soricidae).MethodsWe compiled body size data for 51 species of Sorex and measured pelage brightness from museum specimens for 43 species. We sourced bioclimatic data across the geographical range of each species as well as specific to the museum specimen localities. For comparative purposes, we also estimated a Sorex phylogeny using existing sequence data. To test Bergmann's and Gloger's rules, we constructed phylogenetic least squares models considering latitude, altitude, and bioclimatic variables as predictors of interspecific variation in body size and pelage brightness across Sorex. We then performed these tests separately for the Palaearctic and Nearctic lineages.ResultsSorex exhibits wide variation in both body size and pelage brightness. In models of the entire genus and of the Nearctic clade, neither trait is significantly predicted by the variables tested. A decrease in pelage brightness in the Palaearctic clade is significantly predicted by increasing mean annual temperature and annual precipitation, but only when considering climatic data specific to the measured specimen localities.Main conclusionsSorex does not conform to Bergmann's rule. This result aligns with intraspecific studies suggesting Bergmann's rule is less evident in smaller taxa, but it counters others that found support for the rule in North American and European assemblages. Different patterns in pelage evolution across the Nearctic and Palaearctic clades may result from different historical climatic pressures; however, the significance of the relationship between climate and pelage evolution is dependent on the specificity of the climatic data. Sorex may be a useful focal taxon for exploring the relationship between intra‐ and interspecific ecogeographical patterns as well as the relative roles of morphological, behavioural, physiological, and life history characteristics in explaining the ability to persist in climatically challenging environments.

PHYLACINE 1.2: The Phylogenetic Atlas of Mammal Macroecology.

Data needed for macroecological analyses are difficult to compile and often hidden away in supplementary material under non-standardized formats. Phylogenies, range data, and trait data often use conflicting taxonomies and require ad hoc decisions to synonymize species or fill in large amounts of missing data. Furthermore, most available data sets ignore the large impact that humans have had on species ranges and diversity. Ignoring these impacts can lead to drastic differences in diversity patterns and estimates of the strength of biological rules. To help overcome these issues, we assembled PHYLACINE, The Phylogenetic Atlas of Mammal Macroecology. This taxonomically integrated platform contains phylogenies, range maps, trait data, and threat status for all 5,831 known mammal species that lived since the last interglacial (~130,000 years ago until present). PHYLACINE is ready to use directly, as all taxonomy and metadata are consistent across the different types of data, and files are provided in easy-to-use formats. The atlas includes both maps of current species ranges and present natural ranges, which represent estimates of where species would live without anthropogenic pressures. Trait data include body mass and coarse measures of life habit and diet. Data gaps have been minimized through extensive literature searches and clearly labelled imputation of missing values. The PHYLACINE database will be archived here as well as hosted online so that users may easily contribute updates and corrections to continually improve the data. This database will be useful to any researcher who wishes to investigate large-scale ecological patterns. Previous versions of the database have already provided valuable information and have, for instance, shown that megafauna extinctions caused substantial changes in vegetation structure and nutrient transfer patterns across the globe.

Geographic variation of body size in New World anurans: energy and water in a balance

The validity of Bergmann's rule, perhaps the best known ecogeographical rule, has been questioned for ectothermic species. Here, we explore the interspecific version of the rule documenting body size gradients for anurans across the whole New World and evaluating which environmental variables best explain the observed patterns. We assembled a dataset of body sizes for 2761 anuran species of the Western Hemisphere and conducted assemblage‐based and cross‐species analyses that consider the spatial and phylogenetic structure in the data. In accordance with heat and water‐related explanations for body size clines, we found a consistent association of median body size and potential evapotranspiration across the New World. A relevant role of water availability also emerges, suggesting the joint importance of body size for thermoregulation and hydroregulation in anurans. Anurans do not follow a simple Bergmannian pattern of increasing size towards high latitudes. Consistent with previous regional findings, our Hemisphere‐wide analyses detect that the geographic variation in anuran body sizes is highly dependent on a trade‐off between heat and water balance. The observed size‐climate relationships possibly emerge from the interplay between thermoregulatory abilities and the benefits inherent to reduced surface‐to‐volume ratios in larger species, which decrease the rates of evaporative water loss and favour heat retention. Our results also show how temperature becomes important for species that are directly in contact with the substrate and water, like burrowing and terrestrial anurans, while arboreal species exhibit a body size cline linked with potential evapotranspiration.