Find research datasets worth reusing

Data from: Genotype-specific effects of ericoid mycorrhizae on floral traits and reproduction in Vaccinium corymbosum

PREMISE OF THE STUDY: Most plants interact with mycorrhizal fungi and animal pollinators simultaneously. Yet, the effects of mycorrhizae on pollination are poorly understood. Here, we examined how inoculation with ericoid mycorrhizal fungi affected flowering phenology, floral traits, and reproductive success among eight genotypes of Vaccinium corymbosum (Ericaceae). We asked three overarching questions: 1) do genotypes differ in response to inoculation? 2) How does inoculation affect floral and flowering traits? 3) Are inoculated plants more attractive to pollinators and thus less pollen limited than non-inoculated plants of the same genotype? METHODS: To examine these questions, we experimentally inoculated plants with fungal spores at planting, grew them in the field, and took flowering and floral measurements over two years. In year two, we conducted a hand-pollination experiment to test if plants differed in pollen limitation. KEY RESULTS: Our results demonstrated that inoculated plants had significantly higher levels of colonization for some genotypes but not all, and there were significant floral trait changes in inoculated plants for some genotypes as well. On average, inoculated plants produced significantly larger floral displays, more fruits/inflorescence, and heavier fruits with lower sugar content, than non-inoculated, control plants. Hand pollination enhanced the production of fruits, and fruit mass, for non-inoculated plants but not for those that were inoculated. CONCLUSIONS: Our results demonstrate that ericoid mycorrhizal fungi enhance flowering and alter investment in reproduction in genotype-specific ways. These findings underscore the importance of examining belowground symbionts to fully understand the drivers of aboveground interactions.

Data from: Experimental migration upward in elevation is associated with strong selection on life history traits

One of the strongest biological impacts of climate change has been the movement of species poleward and upward in elevation. Yet, what is not clear, is the extent to which the spatial distribution of locally adapted lineages and ecologically important traits may also shift with continued climate change. Here, we take advantage of a transplant experiment mimicking up-slope seed dispersal for a suite of ecologically-diverse populations of yellow monkeyflower (Mimulus guttatus sensu lato) into a high-elevation common garden during an extreme drought period in the Sierra Nevada mountains, California, USA. We use a demographic approach to quantify fitness and test for selection on life history traits in local vs. lower-elevation populations and in normal vs. drought years to test the potential for up-slope migration and phenotypic selection to alter the distribution of key life history traits in montane environments. We find that lower-elevation populations tend to outperform local populations, confirming the potential for up-slope migration. Although selection generally favored some local montane traits, including larger flowers and larger stem size at flowering, drought conditions tended to select for earlier flowering typical of lower elevation genotypes. Taken together, this suggests that monkeyflower lineages moving upward in elevation could experience selection for novel trait combinations, particularly under warmer and drier conditions that are predicted to occur with continued climate change.

Unique genetic signatures of local adaptation over space and time for diapause, an ecologically relevant complex trait, in Drosophila melanogaster

Organisms living in seasonally variable environments utilize cues such as light and temperature to induce plastic responses, enabling them to exploit favorable seasons and avoid unfavorable ones. Local adapation can result in variation in seasonal responses, but the genetic basis and evolutionary history of this variation remains elusive. Many insects, including Drosophila melanogaster, are able to undergo an arrest of reproductive development (diapause) in response to unfavorable conditions. In D. melanogaster, the ability to diapause is more common in high latitude populations, where flies endure harsher winters, and in the spring, reflecting differential survivorship of overwintering populations. Using a novel hybrid swarm-based genome wide association study, we examined the genetic basis and evolutionary history of ovarian diapause. We exposed outbred females to different temperatures and day lengths, characterized ovarian development for over 2800 flies, and reconstructed their full phased genomes. We found that diapause scored at two different developmental cutoffs has modest heritability, and we identified hundreds of SNPs associated with each of the two phenotypes. Alleles associated with one of the diapause phenotypes tend to be more common at higher latitudes, but these alleles do not show predictable seasonal variation. The collective signal of many small-effect, clinally varying SNPs can plausibly explain latitudinal phenotypic variation seen in North America. SNPs associated with diapause do not exhibit signs of recent selective sweeps, but most are segregating at relatively high frequencies in Africa, suggesting that variation in diapause relies on ancestral polymorphisms. Finally, we utilized outdoor mesocosms to track diapause under natural conditions. We found that hybrid swarms reared outdoors evolved increased propensity for diapause in late fall, whereas indoor control populations experienced no such change. Our results indicate that diapause is a complex, quantitative trait with different evolutionary patterns across time and space.

Efficient weighting methods for genomic best linear unbiased prediction (BLUP) adaption to the genetic architectures of quantitative traits

<a name="_Hlk19877414"></a>Genomic best linear unbiased prediction (GBLUP) assumes equal variance for all marker effects, which is suitable for traits that conform to the infinitesimal model. For traits controlled by major genes, Bayesian methods with shrinkage priors or genome-wide association study (GWAS) methods can be used to identify <a name="_Hlk24974556">causal variants</a> effectively. The information from Bayesian/GWAS methods can be used to construct the weighted genomic relationship matrix (G). However, it remains unclear which methods perform best for traits varying in genetic architecture. Therefore, we developed several methods to <a name="_Hlk23592218">optimize</a> the performance of weighted GBLUP and compare them with other available methods using simulated and real datasets. First, two types of methods (marker effects with local-shrinkage or normal prior) were used to obtain test statistics and estimates for each marker effect. Second, three weighted G matrices were constructed based on the marker information from the first step: (1) the genomic-feature weighted G (GFWG), (2) the estimated marker-variance weighted G (EVWG), and (3) the absolute value of estimated marker-effect weighted G (AEWG). Following the above process, six different weighted GBLUP methods (local-shrinkage/normal prior GF/EV/AE-WGBLUP) were proposed for genomic prediction. Analyses with both simulated and real data demonstrated that these options offer flexibility for optimizing the weighted GBLUP for traits with a broad spectrum of genetic architectures. The advantage of weighting methods over GBLUP in terms of accuracy were trait dependent, ranging from 14.8% to marginal for simulated traits and from 44% to marginal for real traits. Local-shrinkage prior EVWGBLUP is superior for traits mainly controlled by loci of large effect. Normal prior AEWGBLUP performs well for traits mainly controlled by loci of moderate effect. For traits controlled by some loci with large effects (<a name="_Hlk49869847">explain 25%~50% genetic variance</a>) and a range of loci with small effects, GFWGBLUP has advantages. In conclusion, the optimal weighted GBLUP method for genomic selection should take both the genetic architecture and number of QTLs of traits into consideration carefully.

opencc-by-4.0Sep 2020View details →

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Consistent variations in personality traits and their potential for genetic improvement in the biocontrol agent Trichogramma evanescens - Data table and code for data analysis

We provide data and code needed to re-do the analyses and figures presented in our preprint Consistent variations in personality traits and their potential for genetic improvement in the biocontrol agent Trichogramma evanescens (DOI : 10.1101/2020.08.21.257881 ): - data table : data_repetition01.xls, with informations about each column in the file data_repetition_info.pdf - data table : data_individual01.xls, with informations about each column in the file data_indivdual_info.pdf - The R code used to do the analyses : Rscript-Consistent variations in personality traits and their potential for genetic improvement in the biocontrol agent Trichogramma evanescens.R

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Experimental evolution of virulence and associated traits in a Drosophila melanogaster – Wolbachia symbiosis

Evolutionary theory predicts that vertically transmitted symbionts are selected for low virulence, as their fitness is directly correlated to that of their host. In contrast with this prediction, the Wolbachia strain wMelPop drastically reduces its Drosophila melanogaster host lifespan at high rearing temperatures. It is generally assumed that this feature is maintained because the D. melanogaster–wMelPop symbiosis is usually not exposed to environmental conditions in which the symbiont is virulent. To test this hypothesis, we submitted wMelPop-infected D. melanogaster lines to 17 generations of experimental evolution at a high temperature, while enforcing late reproduction. The fly survival was measured at different time points, as well as two traits that have been proposed to be causally responsible for wMelPop virulence: its relative density and the mean number of octomom copies present in its genome. We hypothesised that these conditions would select for a reduced wMelPop virulence, a reduced wMelPop density, and a reduced octomom copy number. Our results indicate that density, octomom copy number and virulence are correlated. However, contrary to our expectations, we could not detect any reduction in virulence during the course of evolution. We discuss the significance of our results with respect to the evolutionary causes of wMelPop virulence and propose that intra-host selection could explain this conundrum.

opencc-by-4.0Apr 2020View details →

Combined effects of rearing and testing temperatures on sperm traits

Temperature experienced during early development can affect a range of adult life history traits. Animals often show seemingly adaptive developmental plasticity – with animals reared at certain temperatures performing better as adults at those temperatures. The extent to which this type of adaptive response occurs in gonadal tissue that affect sperm traits is, however, poorly studied. We initially reared male mosquitofish (Gambusia holbrooki) at either 18oC or 30oC, and then measured their sperm reserves as adults. We also looked at the velocity of their sperm, at both the matched and mismatched temperature. Although males reared at 30oC were larger than those initially reared at 18oC, there was no detectable effect of rearing temperature on absolute sperm number. Sperm swam faster at 30oC than 18oC regardless of the male's rearing temperature. Therefore, we found no evidence of adaptive developmental plasticity. Rearing temperature did, however, significantly influence the relationship between male body size and sperm velocity. Larger males had faster sperm when reared at the warmer temperature, and slower sperm when reared at the cooler temperature. This suggests that rearing temperature could alter the relationship between pre- and post-copulatory sexual selection as male size affects mating success. Finally, there was a positive correlation between velocity at the two test temperatures, suggesting that temperature experienced during sperm competition is unlikely to affect a male's relative fertilisation success.

Using genomic prediction to detect microevolutionary change of a quantitative trait

Detecting microevolutionary responses to natural selection by observing temporal changes in individual breeding values is challenging. The collection of suitable datasets can take many years and disentangling the contributions of the environment and genetics to phenotypic change is not trivial. Furthermore, pedigree-based methods of obtaining individual breeding values have known biases. Here, we apply a genomic prediction approach to estimate breeding values of adult weight in a 35-year dataset of Soay sheep (Ovis aries). Comparisons are made with a traditional pedigree-based approach. During the study period adult body weight decreased, but the underlying genetic component of body weight increased, at a rate that is unlikely to be attributable to genetic drift. Thus cryptic microevolution of greater adult body weight has probably occurred. Genomic and pedigree-based approaches gave largely consistent results. Thus, using genomic prediction to study microevolution in wild populations can remove the requirement for pedigree data, potentially opening up new study systems for similar research.

Experimental evidence of warming-induced disease emergence and its prediction by a trait-based mechanistic model

Predicting the effects of seasonality and climate change on the emergence and spread of infectious disease remains difficult, in part because of poorly understood connections between warming and the mechanisms driving disease. Trait-based mechanistic models combined with thermal performance curves arising from the Metabolic Theory of Ecology (MTE) have been highlighted as a promising approach going forward; however, this framework has not been tested under controlled experimental conditions that isolate the role of gradual temporal warming on disease dynamics and emergence. Here, we provide experimental evidence that a slowly warming host – parasite system can be pushed through a critical transition into an epidemic state. We then show that a trait-based mechanistic model with MTE functional forms can predict the critical temperature for disease emergence, subsequent disease dynamics through time, and final infection prevalence in an experimentally warmed system of Daphnia and a microsporidian parasite. Our results serve as a proof of principle that trait-based mechanistic models using MTE sub-functions can predict warming-induced disease emergence in data-rich systems – a critical step towards generalizing the approach to other systems.

Selection on a small genomic region underpins differentiation in multiple color traits between two warbler species

Speciation is one of the most important processes in biology, yet the study of the genomic changes underlying this process is in its infancy. North American warbler species Setophaga townsendi and S. occidentalis hybridize in a stable hybrid zone, following a period of geographic separation. Genomic differentiation accumulated during geographic isolation can be homogenized by introgression at secondary contact, while genetic regions that cause low hybrid fitness can be shielded from such introgression. Here we examined the genomic underpinning of speciation by investigating: (1) the genetic basis of divergent pigmentation traits between species, (2) variation in differentiation across the genome, and (3) the evidence for selection maintaining differentiation in the pigmentation genes. Using tens of thousands of single nucleotide polymorphisms (SNPs) genotyped in hundreds of individuals within and near the hybrid zone, genome-wide association mapping revealed a single SNP associated with cheek, crown, breast coloration, and flank streaking, reflecting pleiotropy (one gene affecting multiple traits) or close physical linkage of different genes affecting different traits. This SNP is within an intron of the RALY gene, hence we refer to it as the RALY SNP. We then examined between-species genomic differentiation, using both genotyping-by-sequencing and whole genome sequencing. We found that the RALY SNP is within one of the highest peaks of differentiation, which contains three genes known to influence pigmentation: ASIP, EIF2S2, and RALY (the ASIP-RALY gene block). Heterozygotes at this gene block are likely of reduced fitness, as the geographic cline of the RALY SNP has been narrow over two decades. Together, these results reflect at least one barrier to gene flow within this narrow (~200kb) genomic region that modulates plumage difference between species. Despite extensive gene flow between species across the genome, this study provides evidence that selection on a phenotype-associated genomic region maintains a stable species boundary.

Negative trait-based association between abundance of nitrogen fixing trees and long-term tropical forest biomass accumulation

1. Plant functional traits are thought to drive biomass production and biogeochemical cycling in tropical forests, but it remains unclear how nitrogen (N)-fixing legumes influence the functional traits of neighboring trees and forest-wide biomass dynamics. Further, the degree to which effects of N-fixers are density-dependent and may depend on stem size and spatial scale remain largely unknown. 2. Here, we examine 30-years of stem demography data for ~20,000 trees in a lowland tropical forest in Trinidad that span a wide range of functional traits thought to drive aboveground biomass (AGB) dynamics. 3. These forests show positive but decreasing long-term net AGB accumulation resulting from constant average productivity but increasing mortality of non-fixing trees over time. We find that high abundance of N-fixing trees is associated with compositional shifts in non-fixer functional traits that confer lower competitive performance and biomass accumulation. Across tree size classes, most interactions between N-fixers and non-fixers were negative, density dependent, and strongest at smaller spatial scales. 4. Synthesis. Overall, our findings suggest that local trait-based interactions between N-fixing and non-fixing trees can influence long-term carbon accumulation in tropical forests.

Male-male behavioral interactions drive social-dominance mediated differences in ejaculate traits

Higher social status is expected to result in fitness benefits as it secures access to potential mates. In promiscuous species, male reproductive success is also determined by an individual's ability to compete for fertilization after mating by producing high quality ejaculates. However, the complex relationship between a male's investment in social status and ejaculates remains unclear. Here we examine how male social status influences ejaculate quality under a range of social contexts in the pygmy halfbeak Dermogenys cf. collettei, a small, group-living, internally fertilizing freshwater fish. We show that male social status influences ejaculate traits, both in the presence and absence of females. Dominant males produced faster swimming and more viable sperm, two key determinants of ejaculate quality, but only under conditions with frequent male-male behavioral interactions. When male-male interactions were experimentally reduced through the addition of a refuge, differences in ejaculate traits of dominant and subordinate males disappeared. Furthermore, dominant males were in better condition, growing faster and possessing larger livers, highlighting a possible condition-dependence of competitive traits. Contrary to expectations, female presence or absence did not affect sperm swimming speed or testes mass. Together, these results suggest a positive relationship between social status and ejaculate quality in halfbeaks, and highlight that the strength of behavioral interactions between males is a key driver of social-status dependent differences in ejaculate traits.

Python Script used in: Evolution of nuptial gifts and its coevolutionary dynamics with male-like persistence traits of females for multiple mating

Many male animals donate nutritive materials during courtship or mating to their female mates. Donation of large-sized gifts, though costly to prepare, can result in increased sperm transfer during mating and delayed remating of the females, resulting in a higher paternity. Nuptial gifting sometimes causes severe female-female competition for obtaining gifts (i.e., sex-role reversal in mate competition) and female polyandry, changing the intensity of sperm competition and the resultant paternity gains. We built a theoretical model to analyze such coevolutionary feedbacks between nuptial gift size (male trait) and propensity for multiple mating (female trait). Our genetically explicit, individual-based computer simulations demonstrate that a positive correlation between donated gift size and the resultant paternity gain is a requisite for the co-occurrence of large-sized gifts and females' competitive multiple mating for the gifts. When gift donation imposes monandry, exaggeration of nuptial gift size also occurs under the assumption that the last male monopolizes paternity, although it reduces mating opportunities, also occurs under the assumption that the last male monopolizes paternity. We also analyzed the causes and consequences of the evolution of a female persistence trait in trading of nuptial gifts, that is, double receptacles for nuptial gifts known to occur in an insect group with a "female penis" (Neotrogla spp.).

Multidimensional trait morphology predicts ecology across ant lineages

1. Understanding the link between ecology and morphology is a fundamental goal in biology. Ants are diverse terrestrial organisms, known to exhibit ecologically-driven morphological variation. While relationships between individual traits and ecologies have been identified, multidimensional interactions among traits and their cumulative predictive power remain unknown. Because selective pressures may generate convergent syndromes spanning multiple traits, we applied multivariate analyses across a wide sampling of taxa to assess ecomorphological variation in an integrative context. 2. How well does morphology predict ecology? Moreover, are there quantitatively-supported ant ecomorphs? We investigated the links between trait morphology and ecology by assembling a morphometric dataset spanning over 160 species within 110 genera. Because ants occupy a wide range of ecologies, we compiled natural history data on nesting microhabitat, foraging stratum, and functional role into 35 defined niche combinations. This tripartite ecological classification and our morphological dataset were optimized under dimension reduction techniques including Principal Component Analysis, Principal Coordinate Analysis, Linear Discriminant Analysis, and Random Forest supervised machine learning. 3. Our results describe ant ecomorphospace as comprising regions of shared, generalized morphology as well as unique phenotypic space associated with specialized ecologies. Dimension reduction and model-based approaches predict ecology with 77-85% accuracy and Random Forest analysis consistently outperforms LDA. While accounting for shared ancestry, we found eye, antennal scape, and leg morphology to be most informative in differentiating among ecologies. We also note some heterogeneity between trait significance in each ecological aspect (nesting niche, foraging niche, functional role). To increase the utility of ecomorphological classification we simplified our 35 observed niche combinations into 10 ecomorph syndromes, which were also predicted by morphology. The predictive power of these machine learning methods underscores the strong role that ecology has in convergently shaping overall body plan morphology across ant lineages. We include a pipeline for predictive ecomorphological modeling using morphometric data, which may be expanded with additional specimen-based and natural history data.

opencc-zeroJul 2021View details →

Data from: Bee phenology is predicted by climatic variation and functional traits

Climate change is shifting the environmental cues that determine the phenology of interacting species. Plant-pollinator systems may be susceptible to temporal mismatch if bees and flowering plants differ in their phenological responses to warming temperatures. While the cues that trigger flowering are well-understood, little is known about what determines bee phenology. Using Generalized Additive Models, we analyzed time-series data representing 67 bee species collected over nine years in the Colorado Rocky Mountains to perform the first community-wide quantification of the drivers of bee phenology. Bee emergence was sensitive to climatic variation, advancing with earlier snowmelt timing, while later phenophases were best explained by functional traits including overwintering stage and nest location. Comparison of these findings to a long-term flower study showed that bee phenology is less sensitive than flower phenology to climatic variation, indicating potential for reduced synchrony of flowers and pollinators under climate change.

Trait data of European and Maghreb butterflies

Trait-based analyses explaining the different responses of species and communities to environmental changes are increasing in frequency. European butterflies are an indicator group that responds rapidly to environmental changes with extensive citizen science contributions to documenting changes of abundance and distribution. Species traits have been used to explain long- and short-term responses to climate, land-use and vegetation changes. Studies are often characterised by limited traits sets being used, with risks that the relative roles of different traits are not fully explored. Butterfly trait information is dispersed amongst various sources and descriptions sometimes differ between sources. We have drawn together multiple information sets to provide a comprehensive trait database covering 542 taxa and 25 main traits (subdivided into 217 sub-traits) of the butterflies of Europe and North Africa which should serve for improved trait-based ecological, conservation-related, phylogeographic and evolutionary studies of this group of insects. We provide this data in two forms; the basic data and as processed continuous and multinomial data, to enhance its potential usage. A maintained database is available at <a href="https://butterflytraits.github.io/European-Butterfly-Traits/index.html">https://butterflytraits.github.io/European-Butterfly-Traits/index.html</a>

Hidden in the DNA: insights on how multiple historical processes and natural history traits shaped patterns of cryptic diversity in an Amazon leaf-litter lizard Loxopholis osvaldoi (Squamata: Gymnophthalmidae).

Aim: To investigate cryptic diversity and diversification timing in the putatively low-dispersal Amazonian leaf-litter lizard Loxopholis osvaldoi, and to ask how geography (rivers, isolation by distance, IBD), ecological drivers (isolation by environment, IBE) and historical factors (climatic refugia) explain intraspecific genetic variation. Location: Central Amazonia, Brazil. Taxon: Squamata; Gymnophthalmidae; Loxopholis osvaldoi. Methods: We sequenced two mitochondrial and two nuclear markers in 157 individuals. Phylogeographic structure and the occurrence of independent evolving lineages where explored through phylogenetic and coalescent analyses. A species tree and divergence dates of lineages were inferred with BEAST, employing multiple DNA substitution rates. The potential genetic impacts of geographic distance among localities, the environment, and the position of localities in relation to main rivers were tested by Redundancy Analysis (RDA). Results: We detected 11 independently evolving and largely divergent intraspecific lineages. Lineage distribution patterns are complex and do not match any conspicuous barrier to gene flow, except for the Amazon River. Most lineages appear to have originated in the lower Miocene and Pliocene, in disagreement with the Pleistocene refuge hypothesis. IBD, IBE, and rivers appear to have acted in concert establishing and maintaining genetic structure. However, when controlling for other explanatory variables, IBD explains significantly more variation than rivers, IBE, or historical factors. Main conclusions: Our results strongly suggest that L. osvaldoi is a species complex. Future taxonomic work should use an integrative approach to explore whether morphological variation is present and congruent with the genetic data. While the use of a sensitive dating analysis allowed us to better describe the diversification history of L. osvaldoi, the lack of a spatial model of Neogene river dynamics prevents the test of specific, more informative river barrier hypotheses. The data suggest that non-linear correlation analyses (e.g. RDA) should be preferred to detect factors that affect phylogeographic patterns in the Amazon, instead of linear multiple regressions (e.g. Mantel tests). Given the high level of cryptic diversity detected within this and other Amazonian species, we caution against hypothesis tests based solely on the distribution of nominal taxa, which can provide a rather incomplete view of the processes behind Amazonian diversity.

Changes in key traits versus depth and latitude suggest energy-efficient locomotion, opportunistic feeding and light lead to adaptive morphologies of marine fishes.

1. Understanding patterns and processes governing biodiversity along broad-scale environmental gradients, such as depth or latitude, requires an assessment of not just taxonomic richness, but also morphological and functional traits of organisms. Studies of traits can help to identify major selective forces acting on morphology. Currently, little is known regarding patterns of variation in the traits of fishes at broad spatial scales. 2. The aims of this study were: (i) to identify a suite of key traits in marine fishes that would allow assessment of morphological variability across broad-scale depth (50 – 1200 m) and latitudinal (29.15 – 50.91°S) gradients; and (ii) to characterise patterns in these traits across depth and latitude for 144 species of ray-finned fishes in New Zealand waters. 3. Here, we describe three new morphological traits: namely, fin-base-to-perimeter ratio, jaw-length-to-mouth-width ratio, and pectoral-fin-base-to-body-depth ratio. Four other morphological traits essential for locomotion and food acquisition that are commonly measured in fishes were also included in the study. Spatial ecological distributions of individual fish species were characterised in response to a standardised replicated sampling design and morphological measurements were obtained for each species from preserved museum specimens. 4. With increasing depth, fishes, on average, became larger and more elongate, with higher fin-base-to-perimeter ratio and larger jaw-length-to-mouth-width ratio, all of which translates into a more eel-like anguilliform morphology. Variation in mean trait values along the depth gradient was stronger at lower latitudes for fin-base-to-perimeter ratio, elongation and total body length. Average eye size peaked at intermediate depths (500-700 m) and increased with increasing latitude at 700 m. 5. These findings suggest that, in increasingly extreme environments, fish morphology shifts towards a body shape that favours an energy-efficient undulatory swimming style and an increase in jaw-length versus mouth width for opportunistic feeding. Furthermore, increases in eye size with both depth and latitude indicate that changes in both the average ambient light conditions as well as seasonal variations in day-length can act to select ecomorphological adaptations in fishes. 10-Oct-2019

Do visual traits honestly signal floral rewards at community level?

1. The high variability observed in floral traits has been interpreted as resulting from the adaptation of plants to pollinators, as the latter present innate preferences for specific floral traits and impose selection over them. However, some pollinators such as bees can learn to associate floral signals with rewards, thus increasing floral constancy on more rewarding flowers. The integration of all these rewards and cues is markedly important at community level, where co-flowering species compete for pollinators. 2. In order to verify the honesty of the above mentioned signals, we examined the association between floral visual signals (size, colour, symmetry and floral display) and rewards (pollen and nectar) for 98 species in a Mediterranean community. The associations between floral traits were analysed considering the phylogenetic relationship between the different species. 3. Flower colour, size, pollen volume, or amount of sucrose exhibited no phylogenetic signal, which suggests an adaptive evolution in response to different conditions in the pollinator community. Flower size was seen to constitute the most honest signal for pollinators, as this was significantly associated with quantities of pollen and nectar. In contrast, nectar concentration was observed to be positively associated with chromatic contrast. We detected no relationship between flower shape and rewards, on the one hand, or between flower display and rewards, on the other. 4. Our study unequivocally demonstrates the correlation between rewards and the visual signals perceived by bees, the most effective pollinators in the Mediterranean Basin. In the community studied, bees employed flower size at longer distances and chromatic contrast at shorter distances to predict rewards. The limited number of studies existing in this sense indicates that this kind of association appears to be community specific.

The interplay of color and bioacoustic traits in the differentiation of a Southeast Asian songbird complex

Morphological traits have served generations of biologists as a taxonomic indicator, and have been the main basis for defining and classifying species diversity for centuries. A quantitative integration of behavioural characters, such as vocalizations, in studies on biotic differentiation has arisen more recently, and the relative importance of these different traits in the diversification process remains poorly understood. To provide a framework within which to interpret the evolutionary interplay between morphological and behavioral traits, we generated a draft genome of a cryptic Southeast Asian songbird, the Limestone Wren-babbler Napothera crispifrons. We re-sequenced whole genomes of multiple individuals of all three traditional subspecies and of a distinct leucistic population. We demonstrate strong genomic and mitochondrial divergence among all three taxa, pointing to the existence of three species-level lineages. Despite its great phenotypic distinctness, the leucistic population was characterized by shallow genomic differentiation from its neighbor, with only a few localized regions emerging as highly-diverged. Quantitative bioacoustic analysis across multiple traits revealed deep differences especially between the two taxa characterized by limited plumage differentiation. Our study demonstrates that differentiation in these furtive songbirds has resulted in a complex mosaic of color-based and bioacoustic differences among populations. Extreme color differences can be anchored in few genomic loci and may therefore arise and subside rapidly.