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opencc-zeroDec 2016View details →

Data from: Cannibalism and activity rate in larval damselflies increase along a latitudinal gradient as a consequence of time constraints

Background: Predation is ubiquitous in nature. One form of predation is cannibalism, which is affected by many factors such as size structure and resource density. However, cannibalism may also be influenced by abiotic factors such as seasonal time constraints. Since time constraints are greater at high latitudes, cannibalism could be stronger at such latitudes, but we know next to nothing about latitudinal variation in cannibalism. In this study, we examined cannibalism and activity in larvae of the damselfly Lestes sponsa along a latitudinal gradient across Europe. We did this by raising larvae from the egg stage at different temperatures and photoperiods corresponding to different latitudes. Results: We found that the more seasonally time-constrained populations in northern latitudes and individuals subjected to greater seasonal time constraints exhibited a higher level of cannibalism. We also found that activity was higher at north latitude conditions, and thus correlated with cannibalism, suggesting that this behaviour mediates higher levels of cannibalism in time-constrained animals. Conclusions: Our results go counter to the classical latitude-predation pattern which predicts higher predation at lower latitudes, since we found that predation was stronger at higher latitudes. The differences in cannibalism might have implications for population dynamics along the latitudinal gradients, but further experiments are needed to explore this.

opencc-zeroDec 2012View details →

Data from: Parentage analysis of Ansell's mole-rat family groups indicates a high reproductive skew despite relatively relaxed ecological constraints on dispersal

To better understand evolutionary pathways leading to eusociality, interspecific comparisons are needed, which would use a common axis, such as that of reproductive skew, to array species. African mole-rats (Bathyergidae, Rodentia) provide an outstanding model of social evolution because of a wide range of social organizations within a single family; however, their reproductive skew is difficult to estimate, due to their cryptic lifestyle. A maximum skew could theoretically be reached in groups where reproduction is monopolized by a stable breeding pair, but the value could be decreased by breeding-male and breeding-female turnover, shared reproduction and extra-group mating. The frequency of such events should be higher in species or populations inhabiting mesic environments with relaxed ecological constraints on dispersal. To test this prediction, we studied patterns of parentage and relatedness within 16 groups of Ansell's mole-rat (Fukomys anselli) in mesic miombo woodland. Contrary to expectation, there was no shared reproduction (more than one breeder of a particular sex) within the studied groups, and proportion of immigrants and offspring not assigned to current breeding males was low. The within-group parentage and relatedness patterns observed resemble arid populations of 'eusocial' Fukomys damarensis, rather than a mesic population of 'social' Cryptomys hottentotus. As a possible explanation, we propose that the extent ecological conditions affect reproductive skew may be markedly affected by life history and natural history traits of the particular species and genera.

opencc-zeroDec 2013View details →

Data from: Clock gene evolution: seasonal timing, phylogenetic signal, or functional constraint?

Genetic determinants of seasonal reproduction are not fully understood, but may be important predictors of organism responses to climate change. We used a comparative approach to study the evolution of seasonal timing within a fish community in a natural common garden setting. We tested the hypothesis that allelic length variation in the PolyQ domain of a circadian rhythm gene, Clock1a, corresponded to interspecific differences in seasonal reproductive timing across five native and one introduced cyprinid fishes (n = 425 individuals) that co-occur in the Rio Grande, New Mexico, USA. Most common allele lengths were longer in native species that initiated reproduction earlier (Spearman's r = -0.70, p = 0.23). Clock1a allele length exhibited strong phylogenetic signal and earlier spawners were evolutionarily derived. Aside from length variation in Clock1a, all other amino acids were identical across native species, suggesting functional constraint over evolutionary time. Interestingly, the endangered Rio Grande silvery minnow (Hybognathus amarus) exhibited less allelic variation in Clock1a and observed heterozygosity was 2- to 6-fold lower than the five other (non-imperiled) species. Reduced genetic variation in this functionally important gene may impede this species' capacity to respond to ongoing environmental change.

opencc-zeroDec 2016View details →

Data from: The evolution of a complex trait: cuticular hydrocarbons in ants evolve independent from phylogenetic constraints

Cuticular hydrocarbons (CHC) are ubiquitous and highly diverse in insects, serving as communication signal and waterproofing agent. Despite their vital function, the causes, mechanisms and constraints on CHC diversification are still poorly understood. Here, we investigated phylogenetic constraints on the evolution of CHC profiles, using a global dataset of the species-rich and chemically diverse ant genus Crematogaster. We decomposed CHC profiles into quantitative (relative abundances, chain length) and qualitative traits (presence/absence of CHC classes). A species-level phylogeny was estimated using newly generated and previously published sequences from five nuclear markers. Moreover, we reconstructed a phylogeny for the chemically diverse C. levior species group using cytochrome oxidase I. Phylogenetic signal was measured for these traits on genus and clade level and within the chemically diverse C. levior group. For most quantitative CHC traits, phylogenetic signal was low and did not differ from random expectation. This was true on the level of genus, clade and species-group, indicating that CHC traits are evolutionary labile. In contrast, the presence or absence of alkenes and alkadienes was highly conserved within the C. levior group. Hence, the presence or absence of biosynthetic pathways may be phylogenetically constrained, especially at lower taxonomic levels. Our study shows that CHC composition can evolve rapidly, allowing insects to quickly adapt their chemical profiles to external selection pressures, while the presence of biosynthetic pathways appears more constrained. However, our results stress the importance to consider the taxonomic level when investigating phylogenetic constraints.

opencc-by-4.0Jul 2021View details →

Solving Constraint Horn Clauses Modulo Algebraic Data Types and Recursive Functions

This repository contains the benchmark instances used for the evaluation of a new CHC solving algorithm. There are 4 folders: <ol> <li>leon-original. Contains original benchmarks generated by Leon</li> <li>leon-with-rdf. leon-original benchmarks modified by adding RDFs</li> <li>rust-horn-original. Contains original benchmarks generated by RustHorn</li> <li>rust-horn-with-rdf. rust-horn-original benchmarks modified by adding RDFs</li> </ol> The publisher is named anonymous to respect double blind review process

opencc-zeroJul 2021View details →

Analyzing time-energy constraints to understand the links between environmental change and local extinctions in terrestrial ectotherms

Accelerated extinction rates have prompted an increased focus on the interplay between environmental change and species response. The effects of environmental change on thermal opportunity are typically considered through a climate change context. However, habitat alteration can also have strong effects on the thermal environment. Additionally, habitat alteration is considered a leading factor of species extinction, yet few studies address the influence of habitat alteration on thermal opportunity and time-energy budgets in at-risk species. Here we show the strong effects that habitat degradation can have on thermal opportunity, time energy-budgets, and life history demographics of local populations. In the Ozark Mountains of northern Arkansas, woody vegetation encroachment has resulted in a shift in life history traits that appears to play an important role in recent extirpations of Eastern Collared Lizards (Crotaphytus collaris). Populations in degraded habitats experienced a decline in thermal opportunity and less time-at-body temperatures (time-at-Tb) suitable for digestion compared to those in intact habitats. We used our data to model the effect of reduced time-at-Tb on the net assimilated energy available for growth and reproduction. Our model predicts a ca. 46% decline in annual fecundity of individuals – which is similar to empirical observations of reproduction of C. collaris populations in degraded habitats (~49%). We conclude that C. collaris in degraded habitats experienced reduced growth and reproduction primarily as a result of constrained thermal opportunity leading to a decline in digestive processing rates. Our study applies an under-appreciated approach to identify the biophysical and time-energy effects of habitat alteration.

opencc-byJul 2021View details →

Supplementary Dataset for "Experimental constraints on clumped isotope fractionation during BaCO3 precipitation"

This supplementary dataset contains raw geochemical data used to generate figures in the article "Experimental constraints on clumped isotope fractionation during BaCO3 precipitation" by Guo et al.

opencc-zeroJul 2021View details →

Data from: Where Am I? Niche constraints due to morphological specialisation in two Tanganyikan cichlid fish species

Food resource specialisation within novel environments is considered a common axis of diversification in adaptive radiations. Feeding specialisations are often coupled with striking morphological adaptations and exemplify the relation between morphology and diet (phenotype-environment correlations), as seen in, for example, Darwin finches, Hawaiian spiders and, in particular, the cichlid radiations in East Africa. The cichlids' potential to rapidly exploit and occupy a variety of different habitats has previously been attributed to the variability and adaptability of their trophic structures including the pharyngeal jaw apparatus. Here we report a reciprocal transplant experiment designed to explore the adaptability of the cichlid's trophic structures in highly specialised cichlid fish species. More specifically, we forced two common but ecologically distinct cichlid species from Lake Tanganyika, Tropheus moorii (rock-dweller) and Xenotilapia boulengeri (sand-dweller), to live on their preferred as well as on an un-preferred habitat (sand and rock, respectively). We measured their overall performance on the different habitat types and explored whether adaptive phenotypic plasticity is involved in adaptation. We found that, while habitat had no effect on the performance of X. boulengeri, T. moorii performed significantly better in its preferred habitat. Despite an experimental duration of several months we did not find a shift in the morphology of the lower pharyngeal jaw bone that would be indicative of adaptive phenotypic plasticity in this trait.

opencc-zeroAug 2021View details →

Data for: Environmental and anthropogenic constraints on animal space use drive extinction risk worldwide

Animals require a certain amount of habitat to persist and thrive, and habitat loss is one of the most critical drivers of global biodiversity decline. While habitat requirements have been predicted by relationships between species traits and home range size, little is known about constraints imposed by environmental conditions and human impacts on a global scale. Our meta-analysis of 395 vertebrate species shows that global climate gradients in temperature and precipitation exert indirect effects via primary productivity, generally reducing space requirements. Human pressure, however, reduces realized space use due to ensuing limitations in available habitat, particularly for large carnivores. We show that human pressure drives extinction risk by increasing the mismatch between space requirements and availability. We use large-scale climate gradients to predict current species extinction risk across global regions, which also offers an important tool for predicting future extinction risk due to ongoing space loss and climate change.

Figure 8 in Constraints on convergence: hydrophobic hind legs allow some male pollinator fig wasps early access to submerged females

Figure 8. The surface tension (mean ± standard deviation) of the liquid inside figs of Ficus botryocarpa at developmental stages C and D, as measured by capillary rise, compared with distilled water and methanol dilutions.

Figure 5 in Constraints on convergence: hydrophobic hind legs allow some male pollinator fig wasps early access to submerged females

Figure 5. The hind legs of an adult male Ceratosolen corneri (from Ficus botryocarpa) showing the recurved elongate and densely hairy tarsi and the hairy inner face of the tibiae.

Figure 3 in Constraints on convergence: hydrophobic hind legs allow some male pollinator fig wasps early access to submerged females

Figure 3. Scanning electron micrograph of the hind leg tarsal segments of Ceratosolen bisulcatus showing the socketed trichoid setae with grooved surfaces and bent tips.

Figure 2 in Constraints on convergence: hydrophobic hind legs allow some male pollinator fig wasps early access to submerged females

Figure 2. Scanning electron micrograph of a Ceratosolen bisulcatus adult male, showing the short and sparsely hairy hind legs.

Figure 4 in Constraints on convergence: hydrophobic hind legs allow some male pollinator fig wasps early access to submerged females

Figure 4. Scanning electron micrograph of an adult male Ceratosolen corneri (from Ficus botryocarpa) showing the elongate hind legs and the gaster curved forwards beneath the thorax. It is extended farther, in front of the head, during mating.

Figure 7 in Constraints on convergence: hydrophobic hind legs allow some male pollinator fig wasps early access to submerged females

Figure 7. Scanning electron micrograph of the fourth tarsal segment on the hind legs of Ceratosolen corneri (from Ficus botryocarpa) showing the socketed setae (black arrow), the more numerous nonsocketed setae and short microtrichia.

Figure 11 in Constraints on convergence: hydrophobic hind legs allow some male pollinator fig wasps early access to submerged females

Figure 11. Scanning electron micrograph of Sycophaga fusca (Girault, 1915) showing the (a) metasoma and (b) modified peritremata towards the end of the metasoma typical of the males of this genus.

Figure 10 in Constraints on convergence: hydrophobic hind legs allow some male pollinator fig wasps early access to submerged females

Figure 10. Resting position of the hind legs of a male Ceratosolen corneri when floating in a headdown position on the surface of distilled water. The water-repellent legs ensure that the propodeal spriracles (anterior to the base of the gaster) remain clear of the water surface.

Figure 6 in Constraints on convergence: hydrophobic hind legs allow some male pollinator fig wasps early access to submerged females

Figure 6. Scanning electron micrograph of the proximal part of the inner face of the hind coxa of Ceratosolen corneri (from Ficus botryocarpa) showing the non-socketed setae with raised bases and the highly modified cuticular surface.

Figure 1 in Constraints on convergence: hydrophobic hind legs allow some male pollinator fig wasps early access to submerged females

Figure 1. Drawing of a Ceratosolen dentifer Wiebes adult male showing the elongate hairy hind legs and the forward-pointing telescopic metasoma extending forward beneath the head (from Wiebes 1994, fig. 2, reproduced with permission).

Figure 9 in Constraints on convergence: hydrophobic hind legs allow some male pollinator fig wasps early access to submerged females

Figure 9. Variation in resistance to wetting (means ± standard deviation) of male fig wasp hind legs in relation to immersion in liquids with differing surface tensions. The solutions are ordered in sequence of increasing surface tension. Resistance to wetting was scored using an index of 0 (least resistant), 1 or 2 (most resistant), depending on the formation of air bubbles between the hind legs. (a) Ceratosolen corneri from Ficus botryocarpa. (b) Ceratosolen bisulcatus from Ficus septica.