Presence of micronuclei and nuclear abnormalities in Caracara (Polyborus) plancus living in an airport area in southern Brazil.

The aviation sector is believed to be responsible for considerable environmental damage attributed to emission of a large number and amount of pollutants. Airports are often surrounded by forest fragments and humid areas that attract birds of prey and hence may potentially serve as useful bioindicators. The aim of the present study was to examine genotoxic potential in raptors exposed to airport pollution using the micronucleus (MN) test and morphological changes as evidenced by bilateral symmetry. This investigation was conducted at Salgado Filho International Airport of Porto Alegre - RS as well as in private and zoological breeding grounds. The presence of metals was measured in the blood cells of the collected birds. Seventeen birds (Caracara (Polyborus) plancus) were used in this study 11 from exposed and 6 from non-exposed group. The nuclear alterations clearly indicate that organisms exposed to airport pollution exhibited a significantly higher frequency of genetic damage compared to non-exposed birds. Further, manganese and chromium were detected exclusively in the blood of the exposed group. In contrast, the analysis of bilateral symmetry did not detect any significant morphologic differences between the two groups. Therefore, data indicate that blood genotoxic stress occurs in birds of prey living in civil aviation areas as evidenced by MN frequency increase and presence of manganese and chromium.

Hemispheric asymmetries in cortical grey matter of gyri and sulci in modern human populations from South America.

Structural asymmetries of brain regions associated with lateralised functions have been extensively studied. However, there are fewer morphometric analyses of asymmetries of the gyri and sulci of the entire cortex. The current study assessed cortical asymmetries in a sample of healthy adults (N = 175) from an admixed population from South America. Grey matter volume and surface area of 66 gyri and sulci were quantified on T1 magnetic resonance images. The departure from zero of the differences between left and right hemispheres (L-R), a measure of directional asymmetry (DA), the variance of L-R, and an index of fluctuating asymmetry (FA) were evaluated for each region. Significant departures from perfect symmetry were found for most cortical gyri and sulci. Regions showed leftward asymmetry at the population level in the frontal lobe and superior lateral parts of the parietal lobe. Rightward asymmetry was found in the inferior parietal, occipital, frontopolar, and orbital regions, and the cingulate (anterior, middle, and posterior-ventral). Despite this general pattern, several sulci showed the opposite DA compared to the neighbouring gyri, which remarks the need to consider the neurobiological differences in gyral and sulcal development in the study of structural asymmetries. The results also confirm the absence of DA in most parts of the inferior frontal gyrus and the precentral region. This study contributes with data on populations underrepresented in the databases used in neurosciences. Among its findings, there is agreement with previous results obtained in populations of different ancestry and some discrepancies in the middle frontal and medial parietal regions. A significant DA not reported previously was found for the volume of long and short insular gyri and the central sulcus of the insula, frontomarginal, transverse frontopolar, paracentral, and middle and posterior parts of the cingulate gyrus and sulcus, gyrus rectus, occipital pole, and olfactory sulcus, as well as for the volume and area of the transverse collateral sulcus and suborbital sulcus. Also, several parcels displayed significant variability in the left-right differences, which can be partially attributable to developmental instability, a source of FA. Moreover, a few gyri and sulci displayed ideal FA with non-significant departures from perfect symmetry, such as subcentral and posterior cingulate gyri and sulci, inferior frontal and fusiform gyri, and the calcarine, transverse collateral, precentral, and orbital sulci. Overall, these results show that asymmetries are ubiquitous in the cerebral cortex.

Wings are not perfect: increased wing asymmetry in a tropical butterfly as a response to forest fragmentation.

Habitat fragmentation and ecosystem changes have the potential to affect animal populations in different ways. To effectively monitor these changes, biomonitoring tools have been developed and applied to detect changes in population structure and/or individual traits that reflect such changes. Fluctuating asymmetry (FA) represents random deviations from perfect symmetry in bilateral traits from perfect symmetry in response to genetic and/or environmental stresses. In this study, we evaluated the use of FA as a tool to monitor stress caused by forest fragmentation and edge formation, using the tropical butterfly M. helenor (Nymphalidae) as a model species. We collected adult butterflies from three fragments of Atlantic Forest in Brazil encompassing both edge and interior habitats. Four wing traits (wing length, wing width, ocelli area, and ocelli diameter) were evaluated. Butterflies captured at edge sites exhibited higher FA values for wing length and wing width compared to those captured at interior sites, whereas traits related to ocelli did not show differences between the two habitat types. Our results suggest that the differences in abiotic and biotic conditions between forest interior and edges can act as a source of stress, impacting the symmetry of flight-related traits. On the other hand, as ocelli are crucial for butterfly camouflage and counter-predator strategies, our results indicate that this trait may be more conserved. By employing FA, we identified trait-specific responses to habitat fragmentation, thus suggesting its potential as a biomarker for environmental stress that can be used in butterflies to monitor habitat quality and change.

Neuro Postural Optimization Neuromodulation Treatment of Radio Electric Asymmetric Conveyer Technology on Stress and Quality of Life in Institutionalized Children in a Capital City of the Brazilian Amazon.

Background The deviation from perfect bilateral symmetry is defined as fluctuating asymmetry (FA) and is a common phenomenon among living organisms. This deviation from perfection is thought to reflect the environmental pressures experienced during development and, therefore, the FA represents an epigenetic measure of the environmental stress, which affects all living beings from conception, progressively affecting all aspects of life. Rinaldi and Fontani hypothesized that the FA morpho-functional changes are originated by an adaptive motor behavior determined by functional alterations in the cerebellum and neural circuits, not caused by a lesion, but induced by the experienced environmental stress. They identified in the asymmetric activation of symmetrical muscle groups, detectable even in healthy subjects, the expression of the dysfunctional adaptation state of the subject and named this clinical semeiotic phenomenon functional dysmetria (FD). On these premises, they developed the radio electric asymmetric conveyer (REAC) technology, a neuromodulation technology aimed at optimizing the best neuro-psycho-motor strategies in relation to environmental interaction. Neuro postural optimization (NPO) is a neurobiological stimulation treatment administered with the REAC technology and it has been specifically studied to treat the state of dysfunctional adaptation that is revealed through the presence of FD. Aim The purpose of this study was to verify whether a single administration of the REAC NPO treatment can trigger the improvement of the capacity of stress management and the quality of life in a population of children housed in a group home in Macapá, Brazil. Materials and methods The sample of this study consisted of nine children (six boys and three girls) in the age group of 6-11 years, which represented the totality of the children present in the structure. The children was investigated for the assessment of the presence of functional dysmetria and with the Pediatric Quality of Life Inventory TM 4.0 (PedsQL) before and one week after the administration of the REAC NPO. Results The stable disappearance of FD was found in all children at follow-up. In addition, improvements were found in stress management and quality of life, in the physical, emotional, social, and scholastic aspects evaluated with PedsQL. Conclusions It was seen that the REAC NPO neurobiological modulation treatment induced the stable disappearance of FD and triggered the initial improvement of neurophysical aspects also in a population of children housed in a group home in the Amazon region of Macapá, Brazil.

Drosophila Wing Integration and Modularity: A Multi-Level Approach to Understand the History of Morphological Structures.

Static, developmental, and evolutionary variation are different sources of morphological variation which can be quantified using morphometrics tools. In the present study we have carried out a comparative multiple level study of integration (i.e., static, developmental, and evolutionary) to acquire insight about the relationships that exist between different integration levels, as well as to better understand their involvement in the evolutionary processes related to the diversification of Drosophila's wing shape. This approach was applied to analyse wing evolution in 59 species across the whole genus in a large dataset (~10,000 wings were studied). Static integration was analysed using principal component analysis, thus providing an integration measurement for overall wing shape. Developmental integration was studied between wing parts by using a partial least squares method between the anterior and posterior compartments of the wing. Evolutionary integration was analysed using independent contrasts. The present results show that all Drosophila species exhibit strong morphological integration at different levels. The strong integration and overall similarities observed at multiple integration levels suggest a shared mechanism underlying this variation, which could result as consequence of genetic drift acting on the wing shape of Drosophila.

Formal models for the study of the relationship between fluctuating asymmetry and fitness in humans.

OBJECTIVES: To evaluate three of the main verbal models that have been proposed to explain the relationship between fluctuating asymmetry and fitness in humans: the "good genes," the "good development," and the "growth" hypotheses. MATERIALS AND METHODS: A formal model was generated for each verbal model following three steps. First, based on the literature, a theoretical causal model and the theoretical object of inquiry were outlined. Second, an empirical causal model and the targets of inference were defined using observational data of facial asymmetries and life-history traits related to fitness. Third, generalized linear models and causal inference were used as the estimation strategy. RESULTS: The results suggest that the theoretical and empirical assumptions of the "good genes" hypothesis should be reformulated. The results were compatible with most of the empirical assumptions of "the good development" hypothesis but suggest that further discussion of its theoretical assumptions is needed. The results were less informative about the "growth" hypothesis, both theoretically and empirically. There was a positive association between facial fluctuating asymmetry and the number of offspring that was not compatible with any of the empirical causal models evaluated. CONCLUSIONS: Although the three hypotheses focus on different aspects of the link between asymmetry and fitness, their overlap opens the possibility of a unified theory on the subject. The results of this study make explicit which assumptions need to be updated and discussed, facilitating the advancement of this area of research. Overall, this study elucidates the potential benefit of using formal models for theory revision and development.

Orchid bees (Apidae, Euglossini) from Oil Palm Plantations in Eastern Amazon Have Larger but Not Asymmetrical Wings.

Phenotypic variation in both morphology and symmetry of individuals may appear due to environmental stress caused by land-use changes. Here, we evaluated fluctuating asymmetry (FA) and wing size variations of two orchid bee species, Euglossa ignita Smith, 1874 and Eulaema meriana (Olivier, 1789), comparing 11 wing traits. We sampled the individuals from legal reserves (LR), areas of permanent protection (APP), and oil palm plantations (PALM) in Eastern Amazonia. We calculated FA as the absolute difference between the wing measurements made in the right and left wings of specimens and both species' wing size. We corrected each FA measure for possible directional asymmetry bias by subtracting the mean value of the mean FA signed difference to each FA measure. We compared FA and the size of each wing trait of each species between land-use types using one-way ANOVAs. We found no effect of FA between land-use types, but we observed individuals of both species from PALM areas having larger wings than those from LR areas. Our results demonstrate that there seems to be a pressure exerted by land-use change associated with palm oil cultivation favoring individuals with larger wings, although both species had shown substantial permeability of oil palm.

Morfometría geométrica y sus nuevas aplicaciones en ecología y biología evolutiva: Parte 2 / Geometric morphometric and its new applications in ecology and evolutionary biology: Part 2

RESUMEN: La presente revisión entrega una visión actualizada del estudio de la morfometría geométrica y sus aplicaciones más actuales en ecología y biología evolutiva, metodología con una amplia variación en los últimos 5 años de su primera versión en International Journal of Morphology. La Morfometría geométrica es una herramienta que permite evaluar las variaciones morfológicas con factores subyacentes, siendo una herramienta más sensible que la morfometría tradicional, lo que permite detectar mínimos cambios de variación morfológica. Lo que la ha vuelto una herramienta notable para responder preguntas de biología comparada centradas en caracteres anatómicos. En sus comienzos fue una herramienta usada principalmente para responder preguntas taxonómicas, y para diferenciar a nivel de individuos, poblaciones o especies. No obstante, en los últimos años la cantidad de preguntas y problemáticas en las que se aplica, ha diversificado considerablemente, pasando a ser una herramienta muy precisa para responder preguntas de variación morfológica en contextos ecológicos y evolutivos. Ya ha pasado casi media década desde la última revisión del método, por lo que éste trabajo tiene como objetivo analizar los cambios metodológicos y los nuevos enfoques usados en Morfometría geométrica, y presentar una pequeña guía introductoria a éstos nuevos métodos, sus usos y aplicaciones.

SUMMARY: This study provides an updated vision of the study of Geometric Morphometrics and its most recent application in ecology and evolutionary biology, covering a wide variation in methodology occurring in the last 5 years since the first version published in the International Journal of Morphology. Geometric Morphometrics is a tool that allows evaluating morphological variations with underlying factors, with a higher sensitivity than traditional morphology, so that minimum changes of morphological variation can be detected. Therefore, it has turned into an outstanding tool to answer questions of comparative biology focused on anatomic characters. At the beginning, it was a tool mainly used to answer taxonomic questions and for differentiation at individual, population or species level. However, in the last years, the number of questions and problematic on which it is applied, has diversified considerably, turning it into a very accurate tool to answer questions of morphological variation in ecologic and evolutionary contexts. Almost half a decade has elapsed since the last revision of the method, so this work is intended to analyze the methodological changes and the new approaches used in Geometric Morphometrics, including a brief introductory guideline to these new methods, their uses and applications.

Description and ecology of a new species of the cricket genus Endecous (Orthoptera: Grylloidea: Phalangopsidae) in the speleological province of Arcos-Pains-Doresópolis, Southeastern Brazil.

A new cricket species of the genus Endecous Saussure, 1878 is described in the present work found in the speleological province of Arcos-Pains-Doresópolis, which belongs to the limestone group Bambuí, Brazil. Moreover, the spatial distribution of the new species was related to the species Eidmanacris sp., which co-occurs with the former in several caves. Relationships between species abundance and horizontal projection, number of entrances and environmental stability of the caves where these species coexist were evaluated. The presence of bilateral symmetry in individuals of Endecous painensis n. sp. perhaps due to environmental stress caused by mining activities surrounding the cave was also tested. Endecous crickets are commonly observed in the caves, for which the preference by distinct microhabitats and generalist strategies may be key factors explaining colonization and segregation in relation to other cricket species in subterranean habitats. The generalist lifestyle of the here described species may attenuate the effects environmental stresses over development.

Scutation asymmetries in red-footed tortoise Chelonoidis carbonaria Spix, 1824 (Testudines: Testudinidae)

The ability of an individual to withstand random perturbations during its development is considered a good indicator of environmental and genetic stress. A common means of assessing developmental stability is through analysis of fluctuating asymmetry (FA) in bilateral traits. Tortoises, with their large, solid plastron, allow for measurement of body geometry. Their bilateral shell scutes are ideal candidates for asymmetries researches. With this issue in mind we assessed, as a preliminary study, levels of plastron scute asymmetry in a sample of 46 red-footed tortoise Chelonoidis carbonaria from Arauca, N Colombia. We found significative fluctuating asymmetry (FA) but no directional asymmetry, the former not increasing with carapace size and thus indicating that tortoise shells do not become increasingly asymmetrical with age, or in other words, signaling that FA is not being influenced by pholidosis (variability of scale cover mosaic according to the development of the scutes). Asymmetry in plastron shape, although not necessarily apparent at first glance, varied, with gender with males exhibiting higher levels of FA than females. Although we can not identify the potential sources of variation responsible for the observed patterns of developmental instability, we consider this detected form of asymmetry due to unfavorable environmental conditions.(AU)

Scutation asymmetries in red-footed tortoise Chelonoidis carbonaria Spix, 1824 (Testudines: Testudinidae)

The ability of an individual to withstand random perturbations during its development is considered a good indicator of environmental and genetic stress. A common means of assessing developmental stability is through analysis of fluctuating asymmetry (FA) in bilateral traits. Tortoises, with their large, solid plastron, allow for measurement of body geometry. Their bilateral shell scutes are ideal candidates for asymmetries researches. With this issue in mind we assessed, as a preliminary study, levels of plastron scute asymmetry in a sample of 46 red-footed tortoise Chelonoidis carbonaria from Arauca, N Colombia. We found significative fluctuating asymmetry (FA) but no directional asymmetry, the former not increasing with carapace size and thus indicating that tortoise shells do not become increasingly asymmetrical with age, or in other words, signaling that FA is not being influenced by pholidosis (variability of scale cover mosaic according to the development of the scutes). Asymmetry in plastron shape, although not necessarily apparent at first glance, varied, with gender with males exhibiting higher levels of FA than females. Although we can not identify the potential sources of variation responsible for the observed patterns of developmental instability, we consider this detected form of asymmetry due to unfavorable environmental conditions.

Scutation asymmetries in red-footed tortoise Chelonoidis carbonaria Spix, 1824 (Testudines: Testudinidae)

Abstract The ability of an individual to withstand random perturbations during its development is considered a good indicator of environmental and genetic stress. A common means of assessing developmental stability is through analysis of fluctuating asymmetry (FA) in bilateral traits. Tortoises, with their large, solid plastron, allow for measurement of body geometry. Their bilateral shell scutes are ideal candidates for asymmetries researches. With this issue in mind we assessed, as a preliminary study, levels of plastron scute asymmetry in a sample of 46 red-footed tortoise Chelonoidis carbonaria from Arauca, N Colombia. We found significative fluctuating asymmetry (FA) but no directional asymmetry, the former not increasing with carapace size and thus indicating that tortoise shells do not become increasingly asymmetrical with age, or in other words, signaling that FA is not being influenced by pholidosis (variability of scale cover mosaic according to the development of the scutes). Asymmetry in plastron shape, although not necessarily apparent at first glance, varied, with gender with males exhibiting higher levels of FA than females. Although we can not identify the potential sources of variation responsible for the observed patterns of developmental instability, we consider this detected form of asymmetry due to unfavorable environmental conditions.

Developmental instability is associated with estrogenic endocrine disruption in the Chilean native fish species, Trichomycterus areolatus.

Endocrine disrupting compounds (EDCs) are widespread contaminants that alter the normal functioning of the endocrine system. While they cause dysfunctions in essential biological processes, it is unclear whether EDCs also impact developmental stability. In the present study, we investigated the occurrence of estrogenic endocrine disrupting compounds in a small watershed of south-central Chile impacted by anthropogenic activities. Then, we assessed their relationship with internal levels of estrogenic active compounds and fluctuating asymmetry (FA), a proxy of developmental stability in organisms with bilateral symmetry, in a native fish species (Trichomycterus areolatus). Yeast estrogenic screen assays were performed to measure estrogenic activity in river sediments and in male fish tissues collected from 17 sites along the Chillán watershed, and geometric morphometrics used to estimate fluctuating asymmetry based on the shapes of 248 fish skulls. Estrogenic activity was detected both in sediments and male fish tissues at concentrations of up to 1005 ng and 83 ng 17ß-estradiol equivalent/kg dw, respectively. No significant correlation was found between the two. However, fish tissue estrogenicity, water temperature and dissolved oxygen explained >80% of the FA population variation. By showing a significant relationship between estrogenic activity and FA of T. areolatus, our results indicate that developmental stability can be altered by estrogenic endocrine disruption, and that FA can be a useful indicator of sub-lethal stress in T. areolatus populations.

Number of friends and self-perception among Jamaican children: the role of attractiveness and fluctuating asymmetry.

The role that physical attractiveness and fluctuating asymmetry (FA), a measure of developmental instability, play in self-perception and peer associations were explored in a well-studied cohort of Jamaican children using a novel research paradigm where subjects were already known to each other for extensive periods of time. The results showed that how attractive a child was perceived by others was significantly positively correlated with self-ratings of attractiveness. Contrary to findings from WEIRD (Western, Educated, Industrialized, Rich, Democratic) samples, the study found a reversal in the sex differences in self-perceived attractiveness and self-esteem, where Jamaican females rate themselves more attractive and report higher self-esteem than do males. Attractiveness also predicts overall popularity, as measured by desirability as a friend and the percentage of peers who choose an individual as a friend. Attractive individuals of both sexes were chosen more often as 'friends'. A significant correlation was also found between an individual's FA and the average FA of those chosen as friends. However, the effect was primarily due to preferences by males for female friends possessing similar levels of FA, which could be an effective strategy in reducing future mating effort.

Hindlimb lateral and medial acropodial series of cattle are uneven in form / Séries acropodias laterais e mediais são irregulares na forma

In bovines, fore and hind lateral claws are larger than the medial claws and the heel are deeper and the sole thicker. On this anatomical basis, we hypothesized that it must imply a form (size+shape) asymmetry of the digits. To test this hypothesis, we studied the acropodiums (digital series) of 15 young bovines belonging to Brown Pyrenean breed, irrespective of the gender. Dorso-plantar radiographies were obtained for each hindlimb and the form was studied in a sample of 30 hindlimbs (15 right and 15 left). Images were studied by geometric morphometric methods. A set of 7 paired landmarks on medial and lateral digital series and one axial landmark was used for the study. Lateral and medial digits were uneven both in size and shape, expressing both fluctuating and directional asymmetries. Directional asymmetries would suggest a different function in weight bearing. We hypothesize lateral digits serve to stabilize the centre of gravity to a greater extent than medial digits. These findings prompt careful reassessment of the function of each of the digital series during standing and during locomotion in future researches.

Em bovinos, cascos laterais anteriores e posteriores são maiores que os cascos mediais, o talão é mais profundo e o sola mais grosso. Nesta base anatômica, supomos que deve implicar em uma assimetria de forma (tamanho+forma pura) dos dígitos. Para testar essa hipótese, estudamos os acropodiums (série digital) de 15 bovinos jovens pertencentes à raça Pyrenean Brown, independentemente do sexo. Radiografias dorso-plantar foram obtidas para cada membro posterior e a forma foi estudada em uma amostra de 30 membros  (15 à direita e 15 à esquerda). As imagens foram estudadas por métodos geométricos morfométricos. Um conjunto de 7 pontos de referência emparelhados em séries digitais medial e lateral e um marco axial foram usados para o estudo. Os dígitos laterais e medial eram irregulares tanto em tamanho quanto em forma, expressando assimetrias flutuantes e direcionais. Assimimetrias direcionais sugerem uma função diferente para suportar peso. Nós hipotetizamos que os dígitos laterais servem para estabilizar o centro de gravidade em maior medida do que os dígitos mediais. Esses achados sugerem uma reavaliação cuidadosa da função de cada uma das séries digitais durante a posição e durante a locomoção em pesquisas futuras.

Hindlimb lateral and medial acropodial series of cattle are uneven in form / Séries acropodias laterais e mediais são irregulares na forma

In bovines, fore and hind lateral claws are larger than the medial claws and the heel are deeper and the sole thicker. On this anatomical basis, we hypothesized that it must imply a form (size+shape) asymmetry of the digits. To test this hypothesis, we studied the acropodiums (digital series) of 15 young bovines belonging to Brown Pyrenean breed, irrespective of the gender. Dorso-plantar radiographies were obtained for each hindlimb and the form was studied in a sample of 30 hindlimbs (15 right and 15 left). Images were studied by geometric morphometric methods. A set of 7 paired landmarks on medial and lateral digital series and one axial landmark was used for the study. Lateral and medial digits were uneven both in size and shape, expressing both fluctuating and directional asymmetries. Directional asymmetries would suggest a different function in weight bearing. We hypothesize lateral digits serve to stabilize the centre of gravity to a greater extent than medial digits. These findings prompt careful reassessment of the function of each of the digital series during standing and during locomotion in future researches.(AU)

Em bovinos, cascos laterais anteriores e posteriores são maiores que os cascos mediais, o talão é mais profundo e o sola mais grosso. Nesta base anatômica, supomos que deve implicar em uma assimetria de forma (tamanho+forma pura) dos dígitos. Para testar essa hipótese, estudamos os acropodiums (série digital) de 15 bovinos jovens pertencentes à raça Pyrenean Brown, independentemente do sexo. Radiografias dorso-plantar foram obtidas para cada membro posterior e a forma foi estudada em uma amostra de 30 membros  (15 à direita e 15 à esquerda). As imagens foram estudadas por métodos geométricos morfométricos. Um conjunto de 7 pontos de referência emparelhados em séries digitais medial e lateral e um marco axial foram usados para o estudo. Os dígitos laterais e medial eram irregulares tanto em tamanho quanto em forma, expressando assimetrias flutuantes e direcionais. Assimimetrias direcionais sugerem uma função diferente para suportar peso. Nós hipotetizamos que os dígitos laterais servem para estabilizar o centro de gravidade em maior medida do que os dígitos mediais. Esses achados sugerem uma reavaliação cuidadosa da função de cada uma das séries digitais durante a posição e durante a locomoção em pesquisas futuras.(AU)

Fluctuating asymmetry and exposure to pyrethroid insecticides in Triatoma infestans populations in northeastern Argentina.

Fluctuating asymmetry (FA), a phenotypic marker used as indicator of developmental stress or instability, is sometimes associated with insecticide application and resistance. Here we investigated the occurrence and amount of wing size and wing shape FA in Triatoma infestans females and males collected before and 4 months after a community-wide pyrethroid spraying campaign in a well-defined rural area of Pampa del Indio, Argentina. Moderate levels of pyrethroid resistance were previously confirmed for this area, and postspraying house infestation was mainly attributed to this condition. In the absence of insecticide-based selective pressures over the previous 12 years, we hypothesized that 1- if postspraying triatomines were mostly survivors to insecticide spraying (pyrethroid resistant), they would have higher levels of FA than prespraying triatomines. 2- if postspraying triatomines have a selective advantage, they would have lower FA levels than their prespraying counterparts, whereas if postspraying infestation was positively associated with immigrants not exposed to the insecticide, prespraying and postspraying triatomines would display similar FA levels. For 243 adult T. infestans collected at identified sites before insecticide spraying and 112 collected 4 months postspraying, wing size and wing shape asymmetry was estimated from landmark configurations of left and right sides of each individual. At population level, wing size and shape FA significantly decreased in both females and males after spraying. Males displayed greater wing size and shape FA than females. However, at a single peridomestic site that was persistently infested after spraying, FA declined similarly in females whereas the reverse pattern occurred in males. Our results suggest differential survival of adults with more symmetric wings. This pattern may be related to a selective advantage of survivors to insecticide spraying, which may be mediated or not by their pyrethroid-resistant status or to lower triatomine densities after insecticide spraying and the concomitant increase in feeding success.

Fluctuating asymmetry and exposure to pyrethroid insecticides in Triatoma infestans populations in northeastern Argentina

Fluctuating asymmetry (FA), a phenotypic marker used as indicator of developmental stress or instability, is sometimes associated with insecticide application and resistance. Here we investigated the occurrence and amount of wing size and wing shape FA in Triatoma infestans females and males collected before and 4 months after a community-wide pyrethroid spraying campaign in a well-defined rural area of Pampa del Indio, Argentina. Moderate levels of pyrethroid resistance were previously confirmed for this area, and postspraying house infestation was mainly attributed to this condition. In the absence of insecticide-based selective pressures over the previous 12 years, we hypothesized that 1- if postspraying triatomines were mostly survivors to insecticide spraying (pyrethroid resistant), they would have higher levels of FA than prespraying triatomines. 2- if postspraying triatomines have a selective advantage, they would have lower FA levels than their prespraying counterparts, whereas if postspraying infestation was positively associated with immigrants not exposed to the insecticide, prespraying and postspraying triatomines would display similar FA levels. For 243 adult T. infestans collected at identified sites before insecticide spraying and 112 collected 4 months postspraying, wing size and wing shape asymmetry was estimated from landmark configurations of left and right sides of each individual. At population level, wing size and shape FA significantly decreased in both females and males after spraying. Males displayed greater wing size and shape FA than females. However, at a single peridomestic site that was persistently infested after spraying, FA declined similarly in females whereas the reverse pattern occurred in males. Our results suggest differential survival of adults with more symmetric wings. This pattern may be related to a selective advantage of survivors to insecticide spraying, which may be mediated or not by their pyrethroid-resistant status or to lower triatomine densities after insecticide spraying and the concomitant increase in feeding success.

The asymmetry of dermatoglyphic finger ridge counts and the geographic altitude of the Jujenean population in northwest Argentina.

Asymmetry is omnipresent in the living world and therefore is a measure of developmental noise and instability. The main stressing agent in high-altitude ecosystems is hypobaric hypoxia. The variation in bilateral dermatoglyphic symmetry in populations from the Province of Jujuy in northwest Argentina is analyzed, and these results are compared to those for other populations with different ethnic and environmental backgrounds. Fingerprints were collected from 310 healthy students (140 males and 170 females) aged 18-20 years from three localities in Jujuy Province-Abra Pampa (3484 m above sea level), Humahuaca (2939 m above sea level), and San Salvador de Jujuy (1260 m above sea level). Asymmetry by sex was assessed based on radial and ulnar ridge counts to determine its pattern of variability (directional asymmetry [DA], fluctuating asymmetry [FA] and antisymmetry), and asymmetry and diversity indices were calculated. A bivariate plot and principal component analysis (PCA) were used to compare these indices with those for other populations. Homogeneity was found between populations and sexes when radial and ulnar ridges were counted. FA values did not show significant differences by locality or side (ulnar and radial), but significant differences were found by finger and sex, with males showing significantly greater FA values. The asymmetry and diversity indices clearly group the Andean populations and separate them from populations of different ethnic and geographic origin. Only the diversity index showed significant differences by locality in males, which suggests a substantially different genetic component in Abra Pampa male samples.

Craniofacial asymmetry as a marker of socioeconomic status among undocumented Mexican immigrants in the United States.

This study examines levels of fluctuating asymmetry (FA) in Mexican residents, U.S. residents, and undocumented border crossers (UBCs) from Mexico to the United States. Craniofacial structures develop symmetrically under ideal circumstances; however, during periods of developmental stress random deviations from perfect symmetry, or FA, can occur. It is hypothesized that the UBC sample would represent individuals of a lower socioeconomic status (SES) who experienced higher stress levels during development, and that these individuals would consequently have higher levels of FA. Three-dimensional cranial landmarks were collected from 509 individuals representing the three resident groups. Geometric morphometric methods were used to calculate an FA score for each individual. The FA score provides a distance measure that is a scalar measure of the magnitude of FA in each individual. The results show that the difference in the means of the FA scores between UBCs and U.S. residents is 0.43 (p = 0.02), with UBCs showing significantly higher levels of FA compared to U.S. residents. Moreover, Mexican residents' FA levels are intermediate between and not significantly different from the other two samples. These results suggest that levels of FA may prove useful for reconstructing individuals' social and economic circumstances, and that craniofacial asymmetry provides a suitable biological marker for analyzing differences in SES among different groups.