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publicNov 2021View details →

Data from: Differences in sibling cooperation in presence and absence of parental care in a genus with interspecific variation in offspring dependence

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publicApr 2025View details →

Data from: Interspecific and intraspecific variations in root phosphatase activity among tropical tree species with different soil phosphorus associations

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publicSep 2020View details →

Seasonality and interspecific competition shape individual niche variation in co-occurring tetra fish in Neotropical streams

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publicMay 2020View details →

Interspecific variation and elevated CO2 influence the relationship between plant chemical resistance and regrowth tolerance

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opencc-zeroDec 2020View details →

Cis-regulatory variation in the shavenbaby gene underlies intraspecific phenotypic variation, mirroring interspecific divergence in the same trait

Despite considerable progress in recent decades in dissecting the genetic causes of natural morphological variation, there is limited understanding of how variation within species ultimately contributes to species differences. We have studied patterning of the non-sensory hairs, commonly known as "trichomes," on the dorsal cuticle of first-instar larvae of Drosophila. Most Drosophila species produce a dense lawn of trichomes, but a subset of dorsal trichomes were lost in D. sechellia and D. ezoana due entirely to regulatory evolution of the shavenbaby (svb) gene. Here we describe intraspecific variation in dorsal trichome patterns of first-instar larvae of D. virilis that is similar to the trichome pattern variation identified previously between species. We found that 67% of this difference is explained by a QTL that contains svb and that svb expression correlates with trichome variation within D. virilis . Despite using an experimental design with reasonable power to detect a second locus accounting for the remainder of the variance in trichome number, only a single QTL could be mapped, suggesting that multiple other loci each make a small contribution to trichome patterning. Thus, the genetic architecture of intraspecific variation and interspecific differences exhibit similarities and differences that may reflect differences between short-term and long-term evolutionary processes.

opencc-zeroJan 2021View details →

Data from: Interspecific variation in post-disturbance growth responses of a savanna tree community and its implications for escaping the fire trap

Vegetation states in savannas are highly sensitive to tree growth rates, which determine whether individual trees can 'escape' periodic disturbances. Resprouting trees have lopsided shoot:root ratios and are often multi-stemmed, and these variables can modify post-disturbance growth rates and therefore the probability of escape. To date, few studies have systematically examined the implications of interspecific variation in these factors for escape. We conducted a two-year field experiment in lowveld savanna in South Africa and quantified post-disturbance growth characteristics of topkilled trees among 16 species. We examined the dependence of growth on pre-disturbance stem size across species, and the relationship between growth rates and the tendency of trees to produce a few large vs. many small resprouts following disturbance. We found that resprout growth was strongly influenced by pre-disturbance size, but the relationship did not vary among species. In contrast, our results showed that fast-growing species tend to allocate resources towards a few dominant stems, while slow-growing species allocated new biomass towards many smaller stems. Tree species that produced a few large stems also tended to produce individual stems that were tall and thin, further suggesting that the "few large vs. many small" axis is linked to intrinsic species attributes. These findings have implications for understanding how interspecific variation in savanna tree communities may influence their ability to escape disturbance traps.

opencc-zeroDec 2013View details →

Data from: Interspecific hybridisation and interaction with cultivars affect the genetic variation of Ulmus minor and U. glabra in Flanders

Interspecific hybridisation and gene flow from cultivated plants may have profound effects on the evolution of wild species. Considering the cultural history and past use of U. minor and U. glabra trees in Flanders (northern Belgium), we investigated the extent of human impact on the genetic variation of the remaining, supposedly indigenous elm populations. We therefore examined the rate of interspecific hybridisation, which is expected to be higher under human influence, the occurrence of clones within and among locations, the presence of cultivars and their possible offspring. Based on results produced using 385 Amplified Fragment Length Polymorphic (AFLP) markers, 46% of the 106 investigated Flemish elms appeared to be F1 hybrids or backcrosses to one of the parent species, while no F2 hybrids (F1 x F1 progeny) were found. Clonality was mainly found among U. minor and hybrids, which are more likely to form root suckers or sprouts as opposed to U. glabra. The majority of the studied locations (76% of the locations with multiple samples) showed evidence of clonal reproduction. Several, sometimes distant, locations shared a multilocus lineage. We also found indications of gene flow from cultivated elms into native species. It is conceivable that reproductive material has been moved around extensively, obscuring the natural genetic structure of the elm populations. The results help guide the Flemish elm genetic resources conservation program.

opencc-zeroDec 2016View details →

Data from: Intra- and interspecific niche variation as reconstructed from stable isotopes in two ecologically different Ethiopian Rift Valley lakes

1. The concept of species niches has enhanced our understanding of community assembly and food web structure in a variety of ecosystem types. Niche-based species sorting profoundly determines community composition along strong environmental gradients, while interspecific interactions tend to be more important within habitats at local spatial scales. The role of intraspecific niche variation in community assembly and ecosystem functioning has only recently been highlighted. 2. The present study undertakes a quantitative comparison of the trophic structure of fish communities in two iconic Ethiopian Rift Valley lakes, Lake Abaya and Lake Chamo, which are biodiversity hotspots with high societal importance. The lakes differ strongly in ecology: whereas Lake Abaya is turbid due to a very high sediment loading, Lake Chamo is a clear-water lake, which in recent years is, however, rapidly becoming more turbid. Using stable isotopes, we compare the structure of the food web in both lakes, and investigate the degree to which differences in trophic structure between the two lakes are mediated by changes in species composition with fixed within-species niches or rather by flexibility in food acquisition within species. 3. Different food web compartments, including fish and the main basal sources, were sampled in both lakes. We used Bayesian stable isotope mixing models and Bayesian community-wide metrics for a quantitative comparison of the food web structure between the two lakes. 4. We demonstrate that the isotopic niche of the fish community in Lake Abaya is larger and more diversified compared to that in Lake Chamo. Sediment organic material seems to be a major energy source for fish in Abaya, while zooplankton is a dominant source for fish in Chamo. This is consistent with the different ecology of the two lakes, where high turbidity impedes primary and secondary production in Abaya. Differences in trophic structure between the two lakes resulted from intraspecific isotopic niche variation rather than from compositional variation between fish communities. 5. Our results point to the importance of intraspecific variation in feeding ecology of fish communities inhabiting two large Ethiopian Rift Valley Lakes with distinct environmental conditions. We anticipate that the approach we used has strong potential to explore large-scale patterns in food web organization in relation to niche variation across different types of ecosystems.

opencc-zeroDec 2018View details →

Data from: Tropical tree height and crown allometries for the Barro Colorado Nature Monument, Panama: a comparison of alternative hierarchical models incorporating interspecific variation in relation to life history traits

Tree allometric relationships are widely employed for estimating forest biomass and production and are basic building blocks of dynamic vegetation models. In tropical forests, allometric relationships are often modeled by fitting scale-invariant power functions to pooled data from multiple species, an approach that fails to capture changes in scaling during ontogeny and physical limits to maximum tree size and that ignores interspecific differences in allometry. Here, we analyzed allometric relationships of tree height (9884 individuals) and crown area (2425) with trunk diameter for 162 species from the Barro Colorado Nature Monument, Panama. We fit nonlinear, hierarchical models informed by species traits – wood density, mean sapling growth, or sapling mortality – and assessed the performance of three alternative functional forms: the scale-invariant power function and the saturating Weibull and generalized Michaelis–Menten (gMM) functions. The relationship of tree height with trunk diameter was best fit by a saturating gMM model in which variation in allometric parameters was related to interspecific differences in sapling growth rates, a measure of regeneration light demand. Light-demanding species attained taller heights at comparatively smaller diameters as juveniles and had shorter asymptotic heights at larger diameters as adults. The relationship of crown area with trunk diameter was best fit by a power function model incorporating a weak positive relationship between crown area and species-specific wood density. The use of saturating functional forms and the incorporation of functional traits in tree allometric models is a promising approach for improving estimates of forest biomass and productivity. Our results provide an improved basis for parameterizing tropical plant functional types in vegetation models.

opencc-zeroDec 2014View details →

Data from: Interspecific variation in the structural properties of flight feathers in birds indicates adaptation to flight requirements and habitat

1. The functional significance of intra- and interspecific structural variations in the flight feathers of birds is poorly understood. Here, a phylogenetic comparative analysis of four structural features (rachis width, barb and barbule density and porosity) of proximal and distal primary feathers of 137 European bird species was conducted. 2. Flight type (flapping and soaring, flapping and gliding, continuous flapping or passerine type), habitat (terrestrial, riparian or aquatic), wing characteristics (wing area, S and aspect ratio, AR) and moult strategy were all found to affect feather structure to some extent. Species characterized by low wing-beat frequency flight (soaring and gliding) have broader feather rachises (shafts) and feather vanes with lower barb density than birds associated with more active flapping modes of flight. However, the effect of flying mode on rachis width disappeared after controlling for S and AR, suggesting that rachis width is primarily determined by wing morphology. 3. Rachis width and feather vane density are likely related to differences in force distribution across the wingspan during different flight modes. An increase in shaft diameter, barb density and porosity from the proximal to distal wing feathers was found and was highest in species with flapping flight indicating that aerodynamic forces are more biased towards the distal feathers in flapping flyers than in soarers and gliders. 4. Habitat affected barb and barbule density, which was greatest in aquatic species, and within this group, barb density was greater in divers than non-divers, suggesting that the need for water repellency and resistance to water penetration may influence feather structure. However, we found little support for the importance of porosity in water repellency and water penetration, because porosity was similar in aquatic, riparian and terrestrial species and among the aquatic birds (divers and non-divers). We also found that barb density was affected by moult pattern. 5. Our results have broad implications for the understanding of the selection pressures driving flight feather functional morphology. Specifically, the large sample size relative to any previous studies has emphasized that the morphology of flight feathers is the result of a suite of selection pressures. As well as routine flight needs, constraints during moulting, habitat (particularly aquatic) and migratory requirements also affect flight feather morphology. Identifying the exact nature of these trade-offs will perhaps inform the reconstruction of the flying modes of extinct birds.

opencc-zeroDec 2017View details →

Data from: Interspecific variation in ploidy as a key plant trait outlining local extinction risks and community patterns in fragmented landscapes

1. Polyploidy is associated with a plethora of phenotypic and genetic changes yielding transformative effects on species' life-history and ecology. These biological attributes can contribute to the success of species on ecological timescales, as observed in the invasion success or rapid environmental and climatic adaptation of polyploids. However, to date there has been a distinct lack of empirical evidence linking species' local extinction risk, species distributions and community structure in fragmented landscapes with interspecific variation in ploidy. 2. We aimed to investigate the relationship between levels of habitat fragmentation and patterns in both diversity and the frequency of species with different ploidy levels. We included additional persistence- and dispersal related life-history traits, to establish the relative importance of ploidy in determining species richness and frequencies following habitat fragmentation. We therefore collected plant community presence-absence data and landscape data from grassland fragments from South-Central Sweden. 3. Community-level analysis uncovered that interspecific variation in ploidy proved the strongest predictor of plant community species richness and turn-over across grassland fragments. Local extinction risk decreased as ploidy increased, with diploids most prone to local extinction. 4. In the species-level analysis, ploidy outweighed the combined explanatory power of commonly used life-history traits such as clonality, dispersal mechanism and mating system; key predictors of plant species distributions across fragmented landscapes. 5. Ploidy appears to capture parallel variation in a series of advantageous genetic and life-history mechanisms which operate on ecological timescales, emerging as the strongest predictor of local extinction risk even after accounting for variation in other crucial life-history traits. Our results therefore highlight the importance of genomic traits such as ploidy and total chromosome number as valuable factors explaining and predicting local extinction risk in fragmented landscapes.

FIGURE 8 in Quantitative analysis of interspecific and ontogenetic variation in Osteoglossum species (Teleostei: Osteoglossiformes: Osteoglossidae)

FIGURE 8. Principal component analysis including adults of Osteoglossum species. (a) plot characters factor coordinates (b) plot case factor coordinates. Numbers represents species and classes, where, 2= adults of O. ferreirai; 4= adults of O. bicirrhosum.

FIGURE 7 in Quantitative analysis of interspecific and ontogenetic variation in Osteoglossum species (Teleostei: Osteoglossiformes: Osteoglossidae)

FIGURE 7. Principal component analysis including postembryos and juveniles of Osteoglossum species. (a) plot characters factor coordinates (b) plot case factor coordinates. Numbers represents species and classes, where, 1= postembryos and juveniles of O. ferreirai; 3= postembryos and juveniles of O. bicirrhosum.

FIGURE 1 in Quantitative analysis of interspecific and ontogenetic variation in Osteoglossum species (Teleostei: Osteoglossiformes: Osteoglossidae)

FIGURE 1. The two Osteoglossum species: (a) adult specimen of O. bicirrhosum; (b) adult specimen of O. ferreirai; (c) juvenile specimen of O. bicirrhosum; (d) juvenile specimen of O. ferreirai.

FIGURE 6. Correlation between characters 4–5 and 1–6 in Quantitative analysis of interspecific and ontogenetic variation in Osteoglossum species (Teleostei: Osteoglossiformes: Osteoglossidae)

FIGURE 6. Correlation between characters 4–5 and 1–6, including all size classes of Osteoglossum species. Numbers represent species and classes, where, 1= postembryos and juveniles of O. ferreirai; 2= adults of O. ferreirai; 3= postembryos and juveniles of O. bicirrhosum; 4= adults of O. bicirrhosum.

FIGURE 3 in Quantitative analysis of interspecific and ontogenetic variation in Osteoglossum species (Teleostei: Osteoglossiformes: Osteoglossidae)

FIGURE 3. Principal component analysis including all size classes of Osteoglossum species. (a) plot characters factor coordinates (b) plot case factor coordinates. Numbers represent species and classes, where, 1= postembryos and juveniles of O. ferreirai; 2= adults of O. ferreirai; 3= postembryos and juveniles of O. bicirrhosum; 4= adults of O. bicirrhosum.

FIGURE 4. Correlation between characters 13–14 and 1–2 in Quantitative analysis of interspecific and ontogenetic variation in Osteoglossum species (Teleostei: Osteoglossiformes: Osteoglossidae)

FIGURE 4. Correlation between characters 13–14 and 1–2, including all size classes of Osteoglossum species. Numbers represent species and classes, where, 1= postembryos and juveniles of O. ferreirai; 2= adults of O. ferreirai; 3= postembryos and juveniles of O. bicirrhosum; 4= adults of O. bicirrhosum.

FIGURE 2 in Quantitative analysis of interspecific and ontogenetic variation in Osteoglossum species (Teleostei: Osteoglossiformes: Osteoglossidae)

FIGURE 2. Morphometric characters used in Aitchinson analysis: Standard length (1–6); head length (1–2); premaxillacleithrum length (1–3); predorsal length (1–4); postdorsal length (1–5); preanal length (1–8); prepectoral length (1–10); premaxillacoracoid length (1–11); premaxillainfraorbital length (1–12); snout length (1–13); premaxillaopercular length (1–15); eye diameter (13–14); occiputdorsal length; (2–4); occiputpostdorsal length (2–5); occiputcaudal length (2–6); occiputanal length (2–8); occiputpectoral length (2–10); head depth (2–11); dorsal fin length (4–5); analdorsal length (8–4); analpostdorsal length (8–5); anal fin length (8–7).

opennotspecifiedFeb 2007View details →

FIGURE 4 in Osteological characterization of four putative species of the genus Adenomera (Anura: Leptodactylidae), with comments on intra- and interspecific variation

FIGURE 4. Manus of OTU 1, QCAZ 6192 from Ecuador. b–p: base of the prepollex; p: prepollex; r: radiale; ra: radius; s: sesamoid; u: ulnare; ul: ulna; y: element y; 2: distal carpal 2; 5–4–3: distal carpal 5 + distal carpal 4 + distal carpal 3.