The loss of riparian vegetation along streams causes morphological divergences in functional traits of semiaquatic insects (Heteropteran: Gerromorpha) in the eastern Amazon.

Understanding the effects of mining activities on Amazonian streams and their impact on aquatic communities is of paramount importance in the current context of resource overexploitation in society. In this study, we assessed the significance of the environment and interspecific interactions on the organization patterns of semiaquatic insect species in a mineral extraction region in the eastern Amazon. We utilized the morpho functional characteristics of 22 species from the suborder Gerromorpha (Heteropteran), considering both the abundance and sexual dimorphism of these species. Additionally, we quantified the density of riparian vegetation surrounding each stream to categorize sampling points and evaluate whether there are differences in species distribution patterns among categories. We sampled 16 sites, categorized into two treatments based on the percentage of riparian vegetation in forested and deforested areas located in the Capim River Basin. We did not find the action of environmental filters on the total assembly; however, we found significant morphological divergence for all the traits analyzed. On the other hand, the separation of streams into treatments with different portions of riparian vegetation showed that there are significant differences between them regarding species distribution patterns. Forested streams within a 500-m radius have species distributed over a larger area, indicating that these streams have greater resource availability or that species can use these resources more efficiently. Our results demonstrate the importance of riparian vegetation for the studied communities, as well as for mitigating the impacts caused by mining activities.

Testing intra-species variation in allocation to growth and defense in rubber tree (Hevea brasiliensis).

Background: Plants allocate resources to growth, defense, and stress resistance, and resource availability can affect the balance between these allocations. Allocation patterns are well-known to differ among species, but what controls possible intra-specific trade-offs and if variation in growth vs. defense potentially evolves in adaptation to resource availability. Methods: We measured growth and defense in a provenance trial of rubber trees (Hevea brasiliensis) with clones originating from the Amazon basin. To test hypotheses on the allocation to growth vs. defense, we relate biomass growth and latex production to wood and leaf traits, to climate and soil variables from the location of origin, and to the genetic relatedness of the Hevea clones. Results: Contrary to expectations, there was no trade-off between growth and defense, but latex yield and biomass growth were positively correlated, and both increased with tree size. The absence of a trade-off may be attributed to the high resource availability in a plantation, allowing trees to allocate resources to both growth and defense. Growth was weakly correlated with leaf traits, such as leaf mass per area, intrinsic water use efficiency, and leaf nitrogen content, but the relative investment in growth vs. defense was not associated with specific traits or environmental variables. Wood and leaf traits showed clinal correlations to the rainfall and soil variables of the places of origin. These traits exhibited strong phylogenetic signals, highlighting the role of genetic factors in trait variation and adaptation. The study provides insights into the interplay between resource allocation, environmental adaptations, and genetic factors in trees. However, the underlying drivers for the high variation of latex production in one of the commercially most important tree species remains unexplained.

Variation in the Floral Morphology of Prosthechea karwinskii (Orchidaceae), a Mexican Endemic Orchid at Risk.

Prosthechea karwinskii is an orchid endemic to Mexico, threatened by the destruction of its habitat and the extraction of specimens to meet its demand for ornamental and religious use. Most of its populations, including the most locally abundant ones, are found in Oaxaca state. Variations in some floral traits have been observed in these populations. We implemented a morphometric analysis to assess their floral variation and identify the most significant characters in the morphological patterns of this orchid. Floral samples were collected from 17 populations of P. karwinskii in Oaxaca, as well as from specimens used as ornaments during Easter in an Oaxacan community (Zaachila), whose origin is unknown. Sampling of natural populations covered the environmental, geographic, and morphological variation of the species. We performed an analysis of variance (ANOVA), principal component analysis (PCA), canonical variate analysis (CVA), and cluster analysis, including 185 individuals and 45 variables (12 of them were discarded in the multivariate analyses due to high correlation). Characters of the column, lateral sepal, and labellum were most informative for the observed morphological patterns. Albarradas showed the greatest morphological differentiation, mainly due to the column. In general, individuals from the same locality tended to overlap more, especially the populations of Jaltianguis and Yahuiche, which were different from the geographically close population of Etla. Teposcolula presented the highest values in perianth characters, unlike Sola_Rancho Viejo. The specimens recovered from religious ornaments were morphologically more similar to those from Yanhuitlan and Etla. This morphometric analysis identified characters as potential taxonomic markers for P. karwinskii and related species, showing its potential to associate specimens of unknown origin with their probable geographical region. Our work encourages working on collaborative conservation strategies to ensure the long-term permanence of both the species and its traditional uses.

The spatiotemporal context of individual specialization in resource use and environmental associations.

1. Individual niche specialization is widespread in natural populations and has key implications for higher levels of biological organization. This phenomenon, however, has been primarily quantified in resource niche axes, overlooking individual variation in environmental associations (i.e. abiotic conditions organisms experience). 2. Here, we explore what we can learn from a multidimensional perspective of individual niche specialization that integrates resource use and environmental associations into a common framework. 3. By combining predictions from theory and simple simulations, we illustrate how (i) multidimensional intraspecific niche variation and (ii) the spatiotemporal context of interactions between conspecifics scale up to shape emergent patterns of the population niche. 4. Contemplating individual specialization as a multidimensional, unifying concept across biotic and abiotic niche axes is a fundamental step towards bringing this concept closer to the n-dimensional niche envisioned by Hutchinson.

1. A especialização individual de nicho é prevalente em populações naturais e tem implicações importantes para níveis de organização biológica superiores. Esse fenômeno, entretanto, tem sido principalmente quantificado em eixos do nicho que representam o uso de recursos, negligenciando a variação individual em associações ambientais (i.e. as condições abióticas que organismos experimentam). 2. Aqui, exploramos o que podemos aprender a partir de uma perspectiva multidimensional da especialização individual que integra o uso de recursos e associações ambientais em uma abordagem única. 3. Ao combinar predições da teoria e simulações simples, ilustramos como (i) a variação intraespecífica multidimensional de nicho e (ii) o contexto espaço­temporal de interações entre conspecíficos podem moldar padrões emergentes do nicho de populações. 4. Encarar a especialização individual como um conceito multidimensional e unificador em eixos do nicho bióticos e abióticos é um passo fundamental na direção de aproximar esse conceito do nicho n­dimensional idealizado por Hutchinson.

Local adaptation to aridity in a widely distributed angiosperm tree species is mediated by seasonal increase of sugars and reduced growth.

Trees in dry climates often have higher concentrations of total non-structural carbohydrates (NSC = starch + soluble sugars) and grow less than conspecifics in more humid climates. This pattern might result from growth being more constrained by aridity than the carbon (C) gain, or reflect local adaptation to aridity, since NSC fuel metabolism and ensure adequate osmoregulation through the supply of soluble sugars (SS), while low growth reduces water and C demands. It has been further proposed that C allocation to storage could come at the expense of growth (i.e., a growth-storage trade-off). We examined whether NSC and growth reflect local adaptation to aridity in Embothrium coccineum (Proteaceae), a species with an exceptionally wide niche. To control for any influence of the phenotypic plasticity on NSC and growth, we collected seeds from dry (500 mm year-1) and moist (> 2500 mm year-1) climates and grew seedlings in a common garden experiment for 3 years. We then compared NSC and SS concentrations and pools (i.e., total contents), and the biomass of seedlings at spring, summer, and fall. Seedlings from the dry climate had significantly lower biomass and similar NSC concentrations and pools than seedlings from moist climate, suggesting that reduced growth in arid environments does not result from a prioritization of C allocation to storage but it confers advantages under aridity (e.g., lower transpiration area). Across organs, starch and NSC decreased similarly in seedlings from both climates from spring onward. However, root and stem SS concentrations increased during the growing season, and these increases were significantly higher in seedlings from the dry climate. The greater SS accumulation in seedlings from the dry climate compared to those from the moist climate demonstrates ecotypic differentiation in the seasonal dynamics of SS, suggesting that SS underlie local adaptation to aridity. (298 words).

Observations on heterodonty within the dentition of the Atlantic Sharpnose Shark, Rhizoprionodon terraenovae (Richardson, 1836), from the north-central Gulf of Mexico, USA, with implications on the fossil record.

The Atlantic Sharpnose Shark, Rhizoprionodon terraenovae (Richardson, 1836), is the most common small coastal requiem shark in the north-central Gulf of Mexico, USA. Despite this fact, little is known about the dental variation within this taxon. To help rectify this shortcoming, we examined 126 male and female R. terraenovae jaws sets across all maturity stages to document the various types of heterodonty occurring in the dentition of this taxon. Quantitative data gathered from a subset of our sample allowed for us to place teeth within the dentition of R. terraenovae into standardized upper and lower parasymphyseal/symphyseal, anterior lateral, and posterior tooth groups. As with all carcharhinid sharks, the dentition of R. terraenovae exhibits monognathic and dignathic heterodonty. We also observed significant ontogenetic heterodonty in the species, as the teeth and dentition progress through five generalized developmental stages as the shark matures. The ontogenetic development of serrations on the teeth appears to be closely related to documented dietary changes as the shark matures. Initial diets are comprised of high percentages of invertebrate prey like shrimp, crabs, and squid, but this transitions through ontogeny to a diet that is more reliant on fishes. We also provide the first documentation of gynandric heterodonty in mature male R. terraenovae, with development of these seasonal teeth likely enabling a male to grasp female sharks during copulation. Our analysis revealed a tremendous amount of variation in the dentition of R. terraenovae, which has direct implications on the taxonomy of fossil Rhizoprionodon. A comparison of the jaws in our sample to those of the extant species of Rhizoprionodon and the morphologically similar Loxodon, Scoliodon, and Sphyrna allowed us to formulate a list of generic-level characteristics to assist with the identification of isolated teeth. When applied to the fossil record, it is shown that some species previously assigned to Rhizoprionodon likely belong to one of the other aforementioned genera. The earliest occurrence of unequivocal Rhizoprionodon teeth in the fossil record are those of the Eocene †R. ganntourensis (Arambourg, 1952), the oldest records of which occur in early Ypresian deposits in Alabama and Mississippi, USA. The early Eocene occurrence of unequivocal fossil Rhizoprionodon teeth in Alabama predates the first occurrence of Negaprion, Galeocerdo, and Carcharhinus teeth in the state, supporting published molecular and morphological phylogenies positing a basal position for Rhizoprionodon within the Carcharhinidae.

An integrative approach to explore species limits in Laelaps mazzai Fonseca, 1939 (Mesostigmata, Laelapidae), a South American widespread mite parasitizing the cricetid Calomys Waterhouse, 1837.

Laelaps mazzai Fonseca, 1939 (Mesostigmata, Laelapidae) parasitizes several species of the widespread South American rodent genus Calomys Waterhouse, 1837. Morphological variation has been noticed within this laelapid but has yet to be analyzed. Since several other species of laelapids that initially were considered generalists have resulted in host-specific species, after further analyses, herein we explored, through morphology and genetics, the variation of this parasite across six species of Calomys, trying to establish if it constitutes a polymorphic species or a complex of cryptic host specific-species. An integrative approach was applied, including principal component and discriminant analyses of females and males and DNA sequences (nuclear region ITS and the COI gene). The obtained results indicate that female mites tend to differentiate only the sizes of their dorsal shield among host species but with extensive overlapping. At the same time the males lack metrical differentiation, and the genetic evidence failed to resolve specific-species clades. We conclude that L. mazzai is a single widespread mite with little genetic and phenotypic differentiation.

Ecologically driven differences in individual diet specialization across three populations of Guiana dolphin.

Populations usually considered foraging generalists may include specialized individuals that feed on a restricted subset of the prey spectrum consumed by the population. By analyzing the time series of δ13C and δ15N values in sequential growth layer groups within tooth dentin, we measured population- and individual-level variation in resource use of three populations of Guiana dolphins (Sotalia guianensis)-Caravelas River, Babitonga Bay, and Norte Bay-along a latitudinal gradient in the southwestern Atlantic Ocean. We show that the Guiana dolphin at Caravelas River is a generalist population consisting of individual dietary specialists, likely due to the absence of other resident dolphin populations thus allowing individuals to target prey across a wide range of habitats. The Babitonga Bay population is also composed of individual specialists potentially due to the selective foraging behavior of some individuals on high-quality prey sources within and near the bay. In contrast, the Norte Bay population comprises individual generalists, which likely reflects its distinctive cohesive social organization, coexistence with two other dolphin species, and an opportunistic foraging strategy in response to resource fluctuations inherent to the southern limit of the species distribution. Although the Guiana dolphin is generally considered to be a dietary generalist at the population level, our findings reveal that the total niche width of populations and the degree of individual diet specialization are highly context dependent, suggesting dietary plasticity that may be related to a latitudinal gradient in resource availability and environmental conditions.

Terpene chemotypes in Gossypium hirsutum (wild cotton) from the Yucatan Peninsula, Mexico.

Cultivated plants of Gossypium hirsutum Cav. (cotton) consistently emit low levels of volatile organic compounds, primarily mono- and sesquiterpenoids, which are produced and stored in pigment glands. In this study, we provide a comprehensive evaluation of the terpene profiles of wild G. hirsutum plants sourced from sites located throughout natural distribution of this species, thus providing the first in-depth assessment of the scope of its intraspecific chemotypic diversity. Chemotypic variation can potentially influence resistance to herbivory and diseases, or interact with abiotic stress such as extreme temperatures. Under controlled environmental conditions, plants were grown from seeds of sixteen G. hirsutum populations collected along the coastline of the Yucatan Peninsula, which is its likely centre of origin. We found high levels of intraspecific diversity in the terpene profiles of the plants. Two distinct chemotypes were identified: one chemotype contained higher levels of the monoterpenes γ-terpinene, limonene, α-thujene, α-terpinene, terpinolene, and p-cymene, while the other chemotype was distinguished by higher levels of α- and ß-pinene. The distribution of chemotypes followed a geographic gradient from west to east, with an increasing frequency of the former chemotype. Concurrent analysis of maternal plants revealed that chemotypes in wild G. hirsutum are highly heritable.

Animal tracking moves community ecology: Opportunities and challenges.

Individual decisions regarding how, why and when organisms interact with one another and with their environment scale up to shape patterns and processes in communities. Recent evidence has firmly established the prevalence of intraspecific variation in nature and its relevance in community ecology, yet challenges associated with collecting data on large numbers of individual conspecifics and heterospecifics have hampered integration of individual variation into community ecology. Nevertheless, recent technological and statistical advances in GPS-tracking, remote sensing and behavioural ecology offer a toolbox for integrating intraspecific variation into community processes. More than simply describing where organisms go, movement data provide unique information about interactions and environmental associations from which a true individual-to-community framework can be built. By linking the movement paths of both conspecifics and heterospecifics with environmental data, ecologists can now simultaneously quantify intraspecific and interspecific variation regarding the Eltonian (biotic interactions) and Grinnellian (environmental conditions) factors underpinning community assemblage and dynamics, yet substantial logistical and analytical challenges must be addressed for these approaches to realize their full potential. Across communities, empirical integration of Eltonian and Grinnellian factors can support conservation applications and reveal metacommunity dynamics via tracking-based dispersal data. As the logistical and analytical challenges associated with multi-species tracking are surmounted, we envision a future where individual movements and their ecological and environmental signatures will bring resolution to many enduring issues in community ecology.

Response to thermal and hydric regimes point to differential inter- and intraspecific vulnerability of tropical amphibians to climate warming.

In Puerto Rico, an island threatened by climate warming, only one of two species of frogs that share part of their distribution has undergone a recent range contraction to higher elevations. We questioned if differences in their physiological response to temperature and dehydration might explain this distributional change. We studied a lowland and a highland population of Eleutherodactylus coqui, a widespread generalist, and E. portoricensis, an endangered species that is currently found only above 600 m. We compared various physiological aspects: operative temperature; temperature selection; critical temperatures; and their response to jumping performance tests at various thermal and hydric regimes. Results revealed that E. portoricensis had the highest CTmin and lowest CTmax and selected a cooler range of temperatures from the experimental gradient. Jumping performance increased with temperature for the three populations until attaining maximum performance. Afterwards, performance dropped drastically until reaching CTmax. Dehydration had a negative effect on performance for both species, particularly on maximum performance. This effect was greatest for E. portoricensis, followed by high-elevation E. coqui. The significantly greater thermo-hydric physiological limitations of E. portoricensis may explain its recent range contraction, potentially, as a response to climate warming. Low-elevation E. coqui had the lowest operative warming tolerance and was the only population to select temperatures like those encountered in their environment, indicating it may be narrowly adapted to local thermal conditions and thus, also vulnerable to climate change. Our results point towards plasticity in the response of E. coqui to varying climatic conditions, and present evidence of different physiological responses between closely related species at the same locality. This work highlights the importance of studying the combined effects of temperature and hydration to understand the response of ectotherms to warming environments and presents further evidence that desiccation may be a limiting factor determining which species may survive.

Monogeneans from Catfishes in Lake Tanganyika. I: Two new species of Bagrobdella (Dactylogyridae) from Auchenoglanis occidentalis (Siluriformes: Claroteidae)

In the framework of the study of Siluriform fish monogeneans of Lake Tanganyika, we described two new species of Bagrobdella Paperna, 1969 from Auchenoglanis occidentalis (Valenciennes, 1840). Bagrobdella vanhovei sp. nov. is characterized by the morphology of its MCO which is unique among its congeners, presenting a non-terminal opening, whereas the other species have a terminal opening, and Bagrobdella vansteenbergei sp. nov. characterized by the size of its hooks, which are almost all of the same size, and its male copulating organ with a unique shape: a sub-terminal opening and no membrane surrounding. The Multivariate analysis done on morphometrical characters shows that the new and already described species are well individualized, except for Bagrobdella parauchenoglanii Akoumba, Pariselle, Tombi & Bilong Bilong, 2017 and Bagrobdella fraudulenta Euzet & Le Brun, 1990 (but these two species are easily distinguishable by their morphology), and that B. vanhovei sp. nov. has a great intra-specific morphometrical variation.

GENETIC DIVERSITY OF Lutzomyia (Nyssomyia) intermedia IN AN ENDEMIC AREA OF AMERICAN CUTANEOUS LEISHMANIASIS, STATE OF PARANÁ, BRAZIL / Diversidad genética de Lutzomyia (Nyssomyia) intermedia en un área endémica de leishmaniasis cutánea americana del estado de Paraná, Brasil

ABSTRACT Lutzomyia intermedia (Diptera: Psychodidae) features as one of the main vectors that are involved in the transmission of American cutaneous leishmaniasis (ACL) in the Neotropical region. However, genetic studies involving this taxon are still incipient and important for understanding the level of variability of different populations, their role, and implications as vectors. The aim of this study was to determine the level of genetic diversity of L. intermedia present in the Ribeira River Valley, an area of ACL transmission in the state of Paraná, Brazil, through the Random amplified polymorphic DNA (RAPD). Two municipalities were chosen to collect sand flies: Cerro Azul (new transmission area of the ACL) and Adrianópolis (endemic area of the ACL). The insects were captured in the house, in the peridomicile and in the wild (forest). Two of the used markers made it possible to estimate the polymorphism of the studied populations, resulting in 40 genotypes, most of them from peridomicile. The dendrogram generated by the analysis with the primer A10 showed different degrees of similarity, suggesting that there may be gene flow in the studied populations. The Principal Coordinate Analysis (PCO) with the A2 primer, was useful in grouping L. intermedia according to its ecological and geographical origin. There was no distinction between the lineages composing the L. intermedia complex. The results of this study, with the record of great genotypic diversity in L. intermedia, may contribute to explain the maintenance of the life cycle of Leishmania braziliensis (Kinetoplastida: Trypanosomatidae) in the region.

RESUMEN Lutzomyia intermedia (Diptera: Psychodidae) es uno de los principales vectores que participan en la transmisión de leishmaniasis cutánea americana (LCA) en la región Neotropical. A pesar de que aún los estudios genéticos que involucran a este taxón son incipientes, tienen una gran importancia para comprender el nivel de variabilidad de las diferentes poblaciones y sus implicaciones en su papel vectorial. El objetivo de este estudio fue determinar el nivel de diversidad genética de L. intermedia presente en el Valle del Río Ribeira, área de transmisión de LCA en el estado de Paraná, Brasil, mediante RAPD (ADN polimórfico amplificado aleatoriamente). Los flebótomos fueron recolectados en los municipios Cerro Azul (nueva área de transmisión de LCA) y Adrianópolis (área endémica de LCA), donde fueron capturados en ambientes residenciales, en el peridomicilio y en el bosque. Dos de los marcadores utilizados permitieron estimar el polimorfismo en las poblaciones estudiadas con la obtención de 40 genotipos, la mayoría de ellos en el peridomicilio. El dendrograma generado por el análisis con el cebador A10 mostró diferentes grados de similitud, lo que sugiere que puede haber flujo gènico en las poblaciones. El Análisis de Coordenadas Principales (PCO) con el cebador A2 fue útil para agrupar L. intermedia según su origen ecológico y geográfico. No hubo distinción entre los linajes que componen el complejo L. intermedia. Los resultados de este estudio, con el registro de gran diversidad genotipica en L. intermedia, pueden contribuir a explicar el mantenimiento del ciclo biológico de Leishmania braziliensis (Kinetoplastida: Trypanosomatidae) en la región.

Color vision and niche partitioning in a diverse neotropical primate community in lowland Amazonian Ecuador.

A recent focus in community ecology has been on how within-species variability shapes interspecific niche partitioning. Primate color vision offers a rich system in which to explore this issue. Most neotropical primates exhibit intraspecific variation in color vision due to allelic variation at the middle-to-long-wavelength opsin gene on the X chromosome. Studies of opsin polymorphisms have typically sampled primates from different sites, limiting the ability to relate this genetic diversity to niche partitioning. We surveyed genetic variation in color vision of five primate species, belonging to all three families of the primate infraorder Platyrrhini, found in the Yasuní Biosphere Reserve in Ecuador. The frugivorous spider monkeys and woolly monkeys (Ateles belzebuth and Lagothrix lagotricha poeppigii, family Atelidae) each had two opsin alleles, and more than 75% of individuals carried the longest-wavelength (553-556 nm) allele. Among the other species, Saimiri sciureus macrodon (family Cebidae) and Pithecia aequatorialis (family Pitheciidae) had three alleles, while Plecturocebus discolor (family Pitheciidae) had four alleles-the largest number yet identified in a wild population of titi monkeys. For all three non-atelid species, the middle-wavelength (545 nm) allele was the most common. Overall, we identified genetic evidence of fourteen different visual phenotypes-seven types of dichromats and seven trichromats-among the five sympatric taxa. The differences we found suggest that interspecific competition among primates may influence intraspecific frequencies of opsin alleles. The diversity we describe invites detailed study of foraging behavior of different vision phenotypes to learn how they may contribute to niche partitioning.

How long does it take to know a species? Redescription, vocalization, and chigger mites infestation pattern in the centenary emBrachycephalus/em emgarbeanus/em (Anura: Brachycephalidae).

Although we celebrate the centennial of Brachycephalus garbeanus' discovery, little progress has been done on understanding this species' biology apart from a few morphological and ecological studies, which includes its redescription based on three specimens from the type-series, microhabitat use, sexual dimorphism in body size, and feeding habits. This species is endemic to the Serra dos Órgãos Mountain range, in the state of Rio de Janeiro, southeastern Brazil. Here we redescribe B. garbeanus based on a wide sampling, including its advertisement and aggressive calls, and also the chigger mites infestation pattern. The advertisement call is longer than 25.8 s with pulsed notes series emitted at an average rate of 2.3 notes/s and 14.1 pulses/s; long inter-note interval with 320 ms; notes with distinctly short pulses (1 to 16 ms); low dominant frequency for this genus (3.0-5.4 kHz) and presence of four harmonics. This species is often parasitized by chigger mites of Hannemania, with a prevalence of infection of 67%, mainly affecting the ventral body surface. Females had a higher prevalence of parasites than males and there was no correlation found between the size of specimens and the number of parasites. Our study, provides an important and overdue taxonomical contribution, including a large amount of novel information for B. garbeanus.

To move or not to move? Skull and lower jaw morphology of the blindsnake Afrotyphlops punctatus (Leach, 1819) (Serpentes, Typhlopoidea, Typhlopidae) with comments on its previously advocated cranial kinesis.

"Scolecophidians" are traditionally known for their several skull and lower jaw autapomorphies, being conspicuously different from alethinophidian snakes in terms of skull shape and function. Although typically known for the absence of any kinetic joint in the skull dermatocranium and neurocranium-mostly due to an adaptation to fossorial habit, literature data have previously suggested a possible cranial kinesis for individuals of Afrotyphlops punctatus based on observations of live and preserved individuals. Given such observations, herein we aim to describe in detail the skull of A. punctatus based on CT-scan images of five specimens, evaluating the skull morphology and inferred function, and also providing valuable discussion on the skull osteology of the genus. Our results suggest that the skull of A. punctatus is similar to other blindsnakes in lacking any trace of snout, or even a frontal-parietal articulation. We also discuss possible osteological data that might be systematically relevant for Typhlopidae both interspecifically and intergenerically.

Plastome genomics in South American maize landraces: chloroplast lineages parallel the geographical structuring of nuclear gene pools.

BACKGROUND AND AIMS: The number of plastome sequences has increased exponentially during the last decade. However, there is still little knowledge of the levels and distribution of intraspecific variation. The aims of this study were to estimate plastome diversity within Zea mays and analyse the distribution of haplotypes in connection with the landrace groups previously delimited for South American maize based on nuclear markers. METHODS: We obtained the complete plastomes of 30 South American maize landraces and three teosintes by means of next-generation sequencing (NGS) and used them in combination with data from public repositories. After quality filtering, the curated data were employed to search for single-nucleotide polymorphisms, indels and chloroplast simple sequence repeats. Exact permutational contingency tests were performed to assess associations between plastome and nuclear variation. Network and Bayesian phylogenetic analyses were used to infer evolutionary relationships among haplotypes. KEY RESULTS: Our analyses identified a total of 124 polymorphic plastome loci, with the intergenic regions psbE-rps18, petN-rpoB, trnL_UAG-ndhF and rpoC2-atpI exhibiting the highest marker densities. Although restricted in number, these markers allowed the discrimination of 27 haplotypes in a total of 51 Zea mays individuals. Andean and lowland South American landraces differed significantly in haplotype distribution. However, overall differentiation patterns were not informative with respect to subspecies diversification, as evidenced by the scattered distribution of maize and teosinte plastomes in both the network and Bayesian phylogenetic reconstructions. CONCLUSIONS: Knowledge of intraspecific plastome variation provides the framework for a more comprehensive understanding of evolutionary processes at low taxonomic levels and may become increasingly important for future plant barcoding efforts. Whole-plastome sequencing provided useful variability to contribute to maize phylogeographic studies. The structuring of haplotype diversity in the maize landraces examined here clearly reflects the distinction between the Andean and South American lowland gene pools previously inferred based on nuclear markers.

Intraspecific variation of trace elements in the kelp gull (Larus dominicanus): influence of age, sex and location.

Hepatic tissue of Larus dominicanus sampled on the coastline of the state of Santa Catarina in Brazil between October 2016 and May 2018 was used to evaluate intraspecific trends and spatial distribution of essential trace elements (Mn, Co, Cu, Zn, Mo and Cr) and non-essential trace elements (As, Pb, Cd, Hg, Ba and V). Principal Component Analysis (PCA) indicated differences in the bioaccumulation of trace elements between female adults and male adults, differences to sex and age were indicated by Kruskal-Wallis test. Heat maps suggest hot spots in locals with high concentration of trace elements in liver of Larus dominicanus. In general, the concentration of trace elements were comparable with values reported in other studies carried out for this species in South America and other regions of the world. The heat maps showed to be a promising tool to identify influences of the locality on bioaccumulation of trace elements in Larus dominicanus.

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 dorsal trichomes, but a subset of these 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 a single large effect QTL, which includes svb, explains most of the trichome number difference between two D. virilis strains and that svb expression correlates with the trichome difference between strains. This QTL does not explain the entire difference between strains, implying that additional loci contribute to variation in trichome numbers. Thus, the genetic architecture of intraspecific variation exhibits similarities and differences with interspecific variation that may reflect differences in long-term and short-term evolutionary processes.

The role of ontogenetic allometry and nonallometric flower shape variation in species-level adaptive diversification - Calceolaria polyrhiza (Calceolariaceae) as a case study.

Organism shape changes predictably during ontogeny, resulting in specific patterns of ontogenetic allometry. In several plant and animal lineages, among-species variation in the shape of mature organisms mirrors variation along their growth trajectories. Hence, ontogenetic allometry is an important bias in evolution. This bias should be stronger at reduced evolutionary time scales, in which among-trait correlations had less time to evolve. Nevertheless, it was shown that adaptation of organism shape frequently involved departures from the ancestral ontogenetic allometry. Moreover, only a moderate fraction of shape variation is correlated with size during ontogeny. Hence, nonallometric variation in shape (NAVSh) is likely to contribute to adaptation, even at reduced evolutionary time scales. We explored the contributions of allometric variation in shape (AVSh), NAVSh, and size variation to adaptive evolution in the angiosperm species Calceolaria polyrhiza. This strongly relies on oil-collecting bees for pollination and experienced transitions in the size of pollinators during the last 2 Ma. Using geometric morphometrics, we described corolla morphology in several populations across its distribution range. Variation in corolla shape was decomposed into an allometric and a nonallometric component, and corolla size was estimated. We then looked for the correlation between these aspects of morphology and the pollinator. Our results suggest that adaptation to pollinators with different sizes relied on NAVSh, which resulted from shifts in the allometric slope and from shape changes that occurred early in flower development. We conclude that NAVSh can contribute to adaptation in flowering plants, even at the species-level.