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Funding: Systematics Research Fund 2019 to KV. John Templeton Foundation (Grant Number(s): #60501; Grant recipient(s): Kevin N Laland). 1. The size of a bird's nest can play a key role in ensuring reproductive success and is determined by a variety of factors. The primary function of the nest is to protect offspring from the environment and predators. Field studies in a number of passerine species have indicated that higher-latitude populations in colder habitats build larger nests with thicker walls compared to lower-latitude populations, but that these larger nests are more vulnerable to predation. Increases in nest size can also be driven by sexual selection, as nest size can act as a signal of parental quality and prompt differential investment in other aspects of care. It is unknown, however, how these microevolutionary patterns translate to a macroevolutionary scale. 2. Here, we investigate potential drivers of variation in the outer and inner volume of open cup nests using a large dataset of nest measurements from 1117 species of passerines breeding in a diverse range of environments. Our dataset is sourced primarily from the nest specimens at the Natural History Museum (UK), complemented with information from ornithological handbooks and online databases. 3. We use phylogenetic comparative methods to test long-standing hypotheses about potential macroevolutionary correlates of nest size, namely nest location, clutch size and variables relating to parental care, together with environmental and geographical factors such as temperature, rainfall, latitude and insularity. 4. After controlling for phylogeny and parental body size, we demonstrate that the outer volume of the nest is greater in colder climates, in island-dwelling species and in species that nest on cliffs or rocks. By contrast, the inner cup volume is associated solely with average clutch size, increasing with the number of chicks raised in the nest. We do not find evidence that nest size is related to the length of parental care for nestlings. 5. Our study reveals that the average temperature in the breeding range, along with several key life-history traits and proxies of predation threat, shapes the global interspecific variation in passerine cup nest size. We also showcase the utility of museum nest collections—a historically underused resource—for large-scale studies of trait evolution. Publisher PDF

Aim: The species diversity and endemism of tropical biotas are major contributors to global biodiversity, but the factors underlying the formation of these systems remain poorly understood. Location: The world's largest tropical island, New Guinea. Time period: Miocene to present. Major taxa studied: Passerine birds. Methods: We first generated a species-level phylogeny of all native breeding passerine birds to analyse spatial and elevational patterns of species richness, species age and phylogenetic diversity. Second, we used an existing dataset on bill morphology to analyse spatial and elevational patterns of functional diversity. Results: The youngest New Guinean species are principally distributed in the lowlands and outlying mountain ranges, with the lowlands also maintaining the majority of non-endemic species. In contrast, many species occurring in the central mountain range are phylogenetically distinct, range-restricted, endemic lineages. Centres of accumulation for the oldest species are in montane forest, with these taxa having evolved unique bill forms in comparison to the remaining New Guinean species. For the morphological generalists, attaining a highland distribution does not necessarily represent the end to dispersal and diversification, because a number of new species have formed in the outlying mountain ranges, following recent colonization from the central range. Main conclusions: We conclude that a general model of tropical montane diversification is that lineages commonly colonize the lowlands, shifting their ranges upslope through time to become range-restricted montane forest endemics, attaining novel functional adaptations to these environments.

Aim We assessed the spatial distribution of four different types of avian specialization throughout Europe, identifying landscape features associated with specialization and quantifying where the Natura 2000 network intersects with areas of high avian specialization. Location Europe. Time period Present day. Taxa studied European breeding birds. Methods We used the European Atlas of breeding birds and four avian specialization measures (diet, foraging behaviour, foraging substrate and habitat). We calculated specialization richness and identified geographical hotspots for each of these ecological traits. We tested whether elevational gradient, landscape heterogeneity or dominant land use predicted each type of specialization richness. We determined which types of European protected areas are most associated with higher specialization richness. Results Diet and foraging substrate specialists increased with elevation, whereas richness of foraging behavioural specialists decreased. There was a greater richness of dietary and habitat specialists in forests than in other environments. The Natura 2000 areas declared under Bird and both directives (Birds and Habitats) intersected with a high dietary, foraging substrate and habitat specialist richness. The richness of foraging behaviour specialists was high in Birds directive areas. Single and multiple hotspots of specialization were greater in protected than non-protected areas. However, almost 30% of specialization hotspots did not intersect with protected areas. Main conclusions Our findings suggest that higher levels of avian specialization in Europe are positively associated with elevation and forested land cover. Importantly, we found that the Natura 2000 network supports all types of avian ecological specialization, albeit mainly in areas declared under both directives.

This study was funded by the Carnegie Trust (#RIG008238 to CS) and John Templeton Foundation (#60501 to KNL). Aim Our aim was to evaluate the role of ecological and life-history factors in shaping global variation in offspring size in a marine clade with a diverse range of parental care behaviours. Location Global. Time period Data sourced from literature published from 1953 until 2019. Major taxa studied Marine teleost fishes. Methods We compiled a species-level dataset of egg and hatch size for 1,639 species of marine fish across 45 orders. We used Bayesian phylogenetic mixed models to evaluate the relationship between offspring size and environmental factors (i.e., mean temperature, chlorophyll-a and dissolved oxygen content together with their annual variation), as well as latitude, reproductive strategy, parental body size and fecundity. We also tested long-standing hypotheses about the co-evolution of offspring size and the presence of parental care in BayesTraits. Results After controlling for parental body size and phylogenetic history, we find that increased egg size is associated with colder and oxygen-rich waters, while hatch size further depends on food supply and the reproductive strategy exhibited by the species. Irrespective of the initial investment in egg size, species with parental care or demersal egg development yield larger hatchlings compared to pelagic spawners. We also demonstrate that hatch size has co-evolved with advanced forms of care in association with parental body but fail to find a relationship with other types of care. Main conclusions Our study shows that parental care behaviours, together with environmental context, influence the evolution of classic life-history trade-offs on a global scale. While the initial investment in eggs is driven primarily by temperature and oxygen content, hatch size also reflects the impact of care an offspring has received throughout development. In support of the 'offspring-first' hypothesis, we find that an increase in hatch size drives the evolution of advanced care provision. Postprint

Animals have diversified into a bewildering variety of morphological forms exploiting a complex configuration of trophic niches. Their morphological diversity is widely used as an index of ecosystem function, but the extent to which animal traits predict trophic niches and associated ecological processes is unclear. Here we use the measurements of nine key morphological traits for >99% bird species to show that avian trophic diversity is described by a trait space with four dimensions. The position of species within this space maps with 70–85% accuracy onto major niche axes, including trophic level, dietary resource type and finer-scale variation in foraging behaviour. Phylogenetic analyses reveal that these form–function associations reflect convergence towards predictable trait combinations, indicating that morphological variation is organized into a limited set of dimensions by evolutionary adaptation. Our results establish the minimum dimensionality required for avian functional traits to predict subtle variation in trophic niches and provide a global framework for exploring the origin, function and conservation of bird diversity.

Aposematic coloration is traditionally considered to signal unpalatability or toxicity. In mammals, most research has focused on just one form of defense, namely, noxious anal secretions, and its black-and-white advertisement as exemplified by skunks. The original formulation of aposematism, however, encompassed a broader range of morphological, physiological, and behavioral defenses, and there are many mammal species with black-and-white contrasting patterns that do not have noxious adaptations. Here, using Bayesian phylogenetic models and data from 1726 terrestrial nonvolant mammals we find that two aspects of conspicuous coloration, black-and-white coloration patterns on the head and body, advertise defenses that are morphological (spines, large body size), behavioral (pugnacity), and physiological (anal secretions), as well as being involved with sexual signaling and environmental factors linked to crypsis. Within Carnivora, defensive anal secretions are associated with complex black-and-white head patterns and longitudinal black-and-white body striping; in primates, larger bodied species exhibit irregular patches of black-and-white pelage; and in rodents, pugnacity is linked to sharp countershading and irregular blocks of white and black pelage. We show that black-and-white coloration in mammals is multifunctional, that it serves to warn predators of several defenses other than noxious anal secretions, and that aposematism in mammals is not restricted to carnivores.

The duration of the developmental period represents a fundamental axis of life history variation in animals, yet broad insights regarding the drivers of this diversity are currently lacking. Here using embryological data combined with information on incubation and fledging periods for 3096 species, we test key mechanistic and adaptive explanations for the evolutionary diversification of developmental durations in birds. First, using data on embryonic development for 20 model species, we show that developmental phases associated primarily with growth are longer and more variable than earlier phases, consistent with a role for allometric constraint in determining the duration of development. Second, using phylogenetic comparative methods, we find that avian developmental durations retain a strong imprint of deep evolutionary history, and that after accounting for these effects, body size differences among species explain less variation (5-22%) in developmental period lengths than previously thought. Finally, by collecting data for a suite of potential explanatory variables, our analyses reveal broad-scale ecological correlates of developmental durations, including variables associated with the relative safety of the developmental environment (e.g. nest height, insularity) and pressures of breeding phenology (e.g. migration). Overall, our results reveal that the combined effects of species’ body size, ecology, and phylogenetic history can account for 62-93% of the variation in developmental durations across birds, providing broad-scale quantitative insight into the relative importance of mechanistic constraints, adaptive evolution and evolutionary constraints in shaping the diversification of this key life-history trait.

Animals have diversified into a bewildering variety of morphological forms exploiting a complex configuration of trophic niches. Their morphological diversity is widely used as an index of ecosystem function, but the extent to which animal traits predict trophic niches and associated ecological processes is unclear. Here we use the measurements of nine key morphological traits for99% bird species to show that avian trophic diversity is described by a trait space with four dimensions. The position of species within this space maps with 70-85% accuracy onto major niche axes, including trophic level, dietary resource type and finer-scale variation in foraging behaviour. Phylogenetic analyses reveal that these form-function associations reflect convergence towards predictable trait combinations, indicating that morphological variation is organized into a limited set of dimensions by evolutionary adaptation. Our results establish the minimum dimensionality required for avian functional traits to predict subtle variation in trophic niches and provide a global framework for exploring the origin, function and conservation of bird diversity.

This research was funded by the European Research Council's Horizon 2020 programme under Starting Grant no. 639291 VARIKIN to F.M.J. Languages do not replace their vocabularies at an even rate: words endure longer if they are used more frequently. This effect, which has parallels in evolutionary biology, has been demonstrated for the core vocabulary, a set of common, unrelated meanings. The extent to which it replicates in closed lexical classes remains to be seen, and may indicate how general this effect is in language change. Here, we use phylogenetic comparative methods to investigate the history of 10 kinship categories, a type of closed lexical class of content words, across 47 Indo-European languages. We find that their rate of replacement is correlated with their usage frequency, and this relationship is stronger than in the case of the core vocabulary, even though the envelope of variation is comparable across the two cases. We also find that the residual variation in the rate of replacement of kinship terms is related to genealogical distance of referent to kin. We argue that this relationship is the result of social changes and corresponding shifts in the entire semantic class of kinship terms, shifts typically not present in the core vocabulary. Thus, an understanding of the scope and limits of social change is needed to understand changes in kinship systems, and broader context is necessary to model cultural evolution in particular and the process of system change in general. Publisher PDF

Th e widespread destruction and fragmentation of natural habitats around the world creates a strong incentive to understand how species and communities respond to such pressures. Th e vast majority of research into habitat fragmentation has focused solely on species presence or absence. However, analyses using innovative functional methodologies off er the prospect of providing new insights into the key questions surrounding community structure in fragmented systems. A key topic in fragmentation research is nestedness (i.e. the ordered composition of species assemblages involving a signifi cant tendency for packing of the presence – absence matrix into a series of proper subsets). To date, nestedness analyses have been concerned solely with nestedness of species membership. Here, we capitalize on the publication of a recent nestedness index (traitNODF) in which the branch lengths of functional dendrograms are incorporated into the standard NODF nestedness index. Using bird community data from 18 forest-habitat-island studies, and measurements of eight continuous functional traits from over 1000 bird species, we conduct the fi rst synthetic analysis of nestedness from a functional perspective (i.e. a nestedness analysis which incorporates how similar species are in terms of their ecological traits). We use two null models to test the signifi cance of any observed functional nestedness, and investigate the role of habitat island area in driving functional nestedness. We also determine whether functional nestedness is driven primarily by species composition or by diff erences in species ’ traits. We found that the majority (94%) of datasets were functionally nested by island area when a permutation null model was used, although only 11 – 22% of datasets were signifi cantly functionally nested when a more conservative fi xed-fi xed null model was used. Species composition was always the most important driver of functional nestedness, but the eff ect of diff erences in species traits was occasionally quite large. Our results isolate the importance of island area in driving functional nestedness where it does occur and show that habitat loss results in the ordered loss of functional traits. Th is analysis demonstrates the potential insights that may derive from testing for ordered patterns of functional diversity.

Background: In articles reporting randomized controlled trials, professional medical writing support is associated with increased adherence to Consolidated Standards of Reporting Trials (CONSORT). We set out to determine whether professional medical writing support was also associated with improved adherence to CONSORT for Abstracts.Methods: Using data from a previously published cross-sectional study of 463 articles reporting randomized controlled trials published between 2011 and 2014 in five top medical journals, we determined the association between professional medical writing support and CONSORT for Abstracts items using a Wilcoxon rank-sum test.Results: The mean proportion of adherence to CONSORT for Abstracts items reported was similar with and without professional medical writing support (64.3% vs 66.5%, respectively; p=0.30). Professional medical writing support was associated with lower adherence to reporting study setting (relative risk [RR]; 0.40; 95% confidence interval [CI], 0.23–0.70), and higher adherence to disclosing harms/side effects (RR 2.04; 95% CI, 1.37–3.03) and funding source (RR 1.75; 95% CI, 1.18–2.60).Conclusions: Although professional medical writing support was not associated with increased overall adherence to CONSORT for Abstracts, important aspects were improved with professional medical writing support, including reporting of adverse events and funding source. This study identifies areas to consider for improvement.

We compare the etymologies of ethnobiological nomenclature in 130 hunter-gatherer and agriculturist languages in Australia, North America, and Amazonia. Previous work has identified correlations between systems of ethnobiological terminology and dominant means of community subsistence, relating stability of terminology to the “salience” of the items. However, the relevance of subsistence patterns to the development of ethnobiological nomenclature requires further investigation, as does the notion of “salience” and how it might relate to etymological stability. The current study probes the relationship between salience and stability and the variability within this relationship. We refine the notion of stability by studying both inheritance and loan rates. We refine the notion of “salience” by separately testing retention and loan rates in flora and fauna vocabulary that might be considered salient for different reasons. Results indicate that the most etymologically stable items are core foodstuffs...

Summary paragraphOrganismal traits may evolve either gradually or in rapid pulses followed by periods of stasis, but the relative importance of these evolutionary models in generating biodiversity has proven difficult to resolve1,2. In addition, while it is often assumed that pulses of trait evolution are associated with speciation events, few studies have explicitly examined how the tempo of trait divergence varies with respect to different geographical phases of speciation. Thus, we still know little about the trajectories of trait divergence over timescales relevant to speciation, or the extent to which these trajectories are shaped by variation in geographical isolation and overlap (sympatry) among incipient species. Here, we combine divergence time estimates, trait measurements, and geographic range data for avian sister species pairs worldwide to examine the tempo and timing of trait divergence during allopatric speciation. We show that divergence in two important ecological traits—?body mass and beak morphology—is best explained by a model including pulses of divergence and periods of relative stasis. We also infer that trait divergence pulses often precede sympatry, and that pulses leading to greater trait disparity are associated with earlier transitions to sympatry. These findings suggest that early pulses of trait divergence promote subsequent transitions to sympatry, rather than such pulses occurring after sympatry has been established, for example via character displacement3. Incorporating pulsed divergence models into allopatric speciation theory helps to resolve some apparently contradictory observations, including widespread instances of both rapid sympatry and prolonged geographical exclusion4-6.

The influence of flying Although birds' eggs are generally ovoid in shape, there is considerable variation in the degree to which they are symmetrical, round, or bottom-heavy. Many hypotheses have been put forward to explain what has driven this variation, with many accepting life history or nesting explanations. Stoddard et al. looked at nearly 50,000 eggs from more than 1400 species from morphological, biophysical, and evolutionary perspectives and found little support for previous hypotheses (see the Perspective by Spottiswoode). Instead, their results suggest that selection for flight adaptations is most likely to be responsible for the variation. Science , this issue p. 1249 ; see also p. 1234

Sternberg (1977a, 1977b) has proposed a comprehensive theory of analogical reasoning involving five distinct components. The purpose of this research was to explore the necessity of two of these components, the inference and mapping processes, when solving simple analogies. Eighth-grade subjects and adult subjects were required to solve 8 target analogies and, in a separate task, to identify the relation) within 16 corresponding word pairs. The data revealed that the subjects were not required to both infer and map the relations of an analogy before correctly solving it as Sternberg’s theory implies. Further, no single process was found to be more valuable than the other processes for accurate analogy solution.

The purpose of this study was to examine incidental word learning from context, that is, whether students would spontaneously focus on and acquire meanings for unknown words encountered in text. Sixty‐five eleventh graders constituted two treatment groups, incidental and intentional learning, and a control group. Materials included (a) a U.S. history text passage embedding 10 target words, and (b) a newspaper article passage on a similar topic which did not embed these words. As a pretest, all subjects were given a list of the target words and 10 distractors; they were asked to indicate whether they knew each word and to supply a definition. Then, the intentional learning group read the text passage with the target words underlined and completed a redefinition task. The incidental learning group read a second form of the passage without the words emphasized, while the control group read the newspaper passage. The following day, all subjects were posttested on the same self‐report and definition tasks. Res...

Aim Whether entire communities of organisms converge towards predictable structural properties in similar environmental conditions remains controversial. We tested for community convergence in birds by comparing the structure of oceanic archipelago assemblages with their respective regional species pools. Location Eighteen major oceanic archipelagos of volcanic origin with global distribution. Major taxa studied Terrestrial birds. Methods We compiled a comprehensive database of morphological trait and phylogenetic data for 6,579 bird species, including species known to have become extinct owing to human activities. We quantified morphological and phylogenetic dissimilarity among species between pairs of archipelagos, using a modified version of the mean nearest taxon distance. We tested for convergence by estimating whether overall mean turnover among archipelagos and pairwise turnover between archipelagos were lower than expected by chance. Results For all land birds, we found that turnover in body plan, body mass and phylogeny among archipelagos was significantly lower than expected. Seventeen (of 18) archipelagos showed significant body plan and phylogenetic similarity with at least one other archipelago. Similar convergent patterns of community assembly were detected in different subsamples of the data (extant species, endemics, native non-endemics, and Passeriformes only). Convergence was more pronounced for extant species than for extant and extinct species combined. Main conclusions Consistent convergence in phylogenetic and morphological structure among archipelagic communities arises through a combination of non-random colonization and in situ adaptation. In addition, by including data from extinct taxa, we show that community convergence both precedes and is accentuated by the anthropogenic extinction of endemic lineages. Our results highlight the potential role of non-random extinction in generating patterns of community convergence and show that convergence existed even before anthropogenic extinctions, owing to deterministic community assembly in similar environmental settings at the global scale.

THE PURPOSE of this study was to examine sixth-grade students' awareness of four expository text structures (collection, comparison/contrast, causation, and problem/solution) and their recall of texts written in those structures. Three measures of awareness with different cognitive demands (use of organization in written recall, use of organization in composition, and response to interviews) were employed to provide a deeper probing of students' awareness than previous research had yielded. Two recall measures were used that have been found to be sensitive to differences in readers' awareness of text structure: subjects' recall of main ideas versus details, and their recall of normal passages versus scrambled passages. The three awareness tasks produced different profiles of sixth-grade students' text structure awareness. The task most typically used in structure awareness studies (use of structure in written recall) was least informative about differences in awareness of the four text structures. The authors