Environmental niche and flight intensity are associated with molecular evolutionary rates in a large avian radiation.

BACKGROUND: Metabolic activity and environmental energy are two of the most studied putative drivers of molecular evolutionary rates. Their extensive study, however, has resulted in mixed results and has rarely included the exploration of interactions among various factors impacting molecular evolutionary rates across large clades. Taking the diverse avian family Furnariidae as a case study, we examined the association between several estimates of molecular evolutionary rates with proxies of metabolic demands imposed by flight (wing loading and wing shape) and proxies of environmental energy across the geographic ranges of species (temperature and UV radiation). RESULTS: We found weak evidence of a positive effect of environmental and morphological variables on mitochondrial substitution rates. Additionally, we found that temperature and UV radiation interact to explain molecular rates at nucleotide sites affected by selection and population size (non-synonymous substitutions), contrary to the expectation of their impact on sites associated with mutation rates (synonymous substitutions). We also found a negative interaction between wing shape (as described by the hand-wing index) and body mass explaining mitochondrial molecular rates, suggesting molecular signatures of positive selection or reduced population sizes in small-bodied species with greater flight activity. CONCLUSIONS: Our results suggest that the demands of flight and environmental energy pose multiple evolutionary pressures on the genome either by driving mutation rates or via their association with natural selection or population size. Data from whole genomes and detailed physiology across taxa will bring a more complete picture of the impact of metabolism, population size, and the environment on avian genome evolution.

A new subspecies in the Turdus nudigenis complex (Aves: Turdidae) from the Cauca River valley of Colombia.

The taxonomy of the T. nudigenis complex has historically been challenging due to the uniformity in plumage among taxa, poorly known vocal variation, and allopatric distributions. Recent phylogenetic analyses have contributed to understanding relationships within the genus; however, much remains to be learned about the extent of phenotypic and genetic differentiation within taxa and its implications in species limits. Here, we analyze the taxonomic status of an enigmatic member of the T. nudigenis complex restricted to the Cauca River valley of Colombia. Our phylogenetic analyses suggest that the Cauca valley population is genetically distinctive from other members of the complex, although its sister relationships with respect to T. grayi and T. nudigenis could not be fully resolved due to paraphyly in the group. Based on similarity of plumage, calls, and biogeographic proximity we tentatively treat this taxon as a new subspecies of T. grayi. Populations from the northern Caribbean T. grayi casius/incomptus and the new taxon inhabit similar environmental conditions, being apparently isolated by the humid Nech lowlands. A formal analysis of vocalizations coupled with a more robust genomic dataset are needed to resolve the systematic affinities and taxonomic status of several members of the T. nudigenis complex.

Analysis of ultraconserved elements supports African origins of narrow-mouthed frogs.

Narrow-mouthed frogs (Anura: Microhylidae) are globally distributed and molecular data suggest the rapid evolution of multiple subfamilies shortly after their origin. Despite recent progress, several subfamilial relationships remain unexplored using phylogenomic data. We analysed 1,796 nuclear ultraconserved elements, a total matrix of 400,664 nucleotides, from representatives of most microhylid subfamilies. Summary method species-tree and maximum likelihood analyses unambiguously supported Hoplophryninae as the earliest diverging microhylid and confirm Chaperininae as a junior synonym of Microhylinae. Given the emerging consensus that subfamilies from mainland Africa diverged early, microhylids have likely occupied the continent for more than 66 million years.

A morphological database for 606 Colombian bird species.

Colombia is the country with the highest bird diversity in the world. Despite active research in ornithology, compelling morphological information of most bird species is still sparse. However, morphological information is the baseline to understand how species respond to environmental variation and how ecosystems respond to species loss. As part of a national initiative, the Instituto Alexander von Humboldt in collaboration with 12 Colombian institutions and seven biological collections, measured up to 15 morphological traits of 9,892 individuals corresponding to 606 species: 3,492 from individuals captured in field and 6,400 from museum specimens. Species measured are mainly distributed in high Andean forest, páramo, and wetland ecosystems. Seven ornithological collections in Colombia and 18 páramo complexes throughout Colombia were visited from 2013 to 2015. The morphological traits involved measurements from bill (total and exposed culmen, bill width and depth), wing (length, area, wingspan, and the distance between longest primary and longest secondary), tail (length and shape), tarsus (length), hallux (length and claw hallux), and mass. The number of measured specimens per species was variable, ranging from 1 to 321 individuals with a median of four individuals per species. Overall, this database gathered morphological information for >30% of Colombian bird diversity. No copyright, proprietary, or cost restrictions apply; the data should be cited appropriately when used.

Niche-tracking migrants and niche-switching residents: evolution of climatic niches in New World warblers (Parulidae).

Differences in life-history traits between tropical and temperate lineages are often attributed to differences in their climatic niche dynamics. For example, the more frequent appearance of migratory behaviour in temperate-breeding species than in species originally breeding in the tropics is believed to have resulted partly from tropical climatic stability and niche conservatism constraining tropical species from shifting their ranges. However, little is known about the patterns and processes underlying climatic niche evolution in migrant and resident animals. We evaluated the evolution of overlap in climatic niches between seasons and its relationship to migratory behaviour in the Parulidae, a family of New World passerine birds. We used ordination methods to measure seasonal niche overlap and niche breadth of 54 resident and 49 migrant species and used phylogenetic comparative methods to assess patterns of climatic niche evolution. We found that despite travelling thousands of kilometres, migrants tracked climatic conditions across the year to a greater extent than tropical residents. Migrant species had wider niches than resident species, although residents as a group occupied a wider climatic space and niches of migrants and residents overlapped extensively. Neither breeding latitude nor migratory distance explained variation among species in climatic niche overlap between seasons. Our findings support the notion that tropical species have narrower niches than temperate-breeders, but does not necessarily constrain their ability to shift or expand their geographical ranges and become migratory. Overall, the tropics may have been historically less likely to experience the suite of components that generate strong selection pressures for the evolution of migratory behaviour.

Ejercicio y la detección del mal agudo de montaña grave / Exercise and the detection of severe acute mountain sickness

El mal agudo de montaña (MAM) es un conjunto de síntomas inespecíficos padecidos por sujetos que ascienden rápidamente desde baja a alta altura sin adecuada aclimatación. Usualmente es autolimitado, pero las formas graves (edema pulmonar y cerebral) pueden causar la muerte. La hipoxemia exagerada en reposo está relacionada con el desarrollo de MAM pero su valor predictivo es limitado. Dado que el ejercicio en altura se acompaña de mayor hipoxemia y síntomas, postulamos el valor predictivo de un simple test de ejercicio para pronosticar MAM grave. Se estudió el valor predictivo de la saturación de oxígeno en reposo y ejercicio submáximo a 2.700 m y 4 300 m en 63 sujetos que ascendían al cerro Aconcagua (6 962 m). Se consideró desaturación de oxígeno con ejercicio a una disminución = 5% respecto al reposo. Se utilizó la escala de Lake-Louise para establecer la presencia de MAM grave. Seis sujetos presentaron MAM grave (9.5%) y requirieron evacuación. La saturación de oxígeno en reposo a 2.700 m no fue significativa para clasificar sujetos que luego desarrollaron MAM grave. Por el contrario, la asociación de desaturación durante el ejercicio a 2.700 m más la saturación inapropiada en reposo a 4.300 m fue significativa para clasificar a los sujetos que desarrollaron MAM grave con un valor predictivo positivo de 80% y un valor predictivo negativo del 97%. Nuestros resultados son relevantes para el montañismo y sugieren la adición de un simple test de ejercicio en la predicción del MAM grave.

Acute mountain sickness (AMS) is a group of non-specific symptoms, seen in subjects that ascend from low to high altitude too quickly, without allowing sufficient time to acclimatize. Usually it is self-limiting, but the severe forms (pulmonary and cerebral edema) can be fatal. Exaggerated hypoxemia at rest is related to later development of AMS but its predictive value is limited. Since exercise at altitude induces greater hypoxemia and symptoms, we postulated the predictive value of a simple exercise test to prognosticate severe AMS. We studied the predictive value of the oxygen saturation during rest and sub-maximum exercise at 2.700 m and 4.300 m in 63 subjects that intended the ascent to Mount Aconcagua (6.962 m). We considered exercise oxygen desaturation to a drop of = 5% respect to the resting value. Lake-Louise Score was used to quantify the presence of severe AMS. Six subjects developed severe AMS (9.5%) and required evacuation. Resting oxygen saturation at 2.700 m was not significant to classify subjects that then developed severe AMS. The association of oxygen desaturation during exercise at 2.700 m plus inappropriate resting oxygen saturation at 4.300 m was significant to classify the subjects that then developed severe AMS with a positive predictive value of 80% and a negative predictive value of 97%. Our results are relevant for mountaineering and suggest the use of a simple exercise test in the prediction of severe AMS.

Factores asociados al desarrollo de obesidad en mujeres jóvenes / Factors associated with the development of obesity in young women

La prevalencia de obesidad en las mujeres se ha duplicado en los últimos 2o años, por lo tanto el indentificar etapas claves y causas de ganancia de peso serán críticas para desarrollar programas de prevención con el fin de detener o disminuir ésta tendencia, en razón del riesgo que representa para el desarrollo de muchas enfermedades crónicas. Objetivo: Determinar factores que predisponen al desarrollo de obesidad en mujeres jóvenes. Métodos: Se tomaron medidas antropométricas "peso, talla, circunferencia de la cintura y cadera, índice de masa corporal (IMC), índice cintura-cadera (ICC). Se recopilaron antecedentes gineco-obtétricos y de actividad física. Resultados: Se encontró un 5.5% de obesidad en la mujeres que no han tenido embarazos y 10.2% en las que han tenido embarazos. Existe correlación positiva entre el IMC con la edad de la persona y el número de embarazos y correlación negativa entre el IMC con la edad de la menarquia. Conclusiones: existe una mayor prevalencia de obesidad en las mujeres que han tenido embarazos. Las variables que mejor predicen el IMC son la edad de la persona, el número de embarazos y la edad de la menarquia.

The prevalence of obesity in women has doubled in the last 2 years, therefore identifying key stages and causes of weight gain will be critical to develop prevention programs in order to stop or decrease this trend, due to the risk which represents for the development of many chronic diseases. Objective: To determine factors that predispose to the development of obesity in young women. Methods: Anthropometric measurements were taken: "weight, height, waist and hip circumference, body mass index (BMI), waist-hip index (CHF). Gyneco-obstetric and physical activity antecedents were collected. Results: 5.5% of obesity was found in women who have not had pregnancies and 10.2% in those who have had pregnancies. There is a positive correlation between BMI and the age of the person and the number of pregnancies, and a negative correlation between BMI and the age of menarche. Conclusions: there is a higher prevalence of obesity in women who have had pregnancies. The variables that best predict BMI are the person's age, the number of pregnancies and the age of menarche.

Prevalencia de osteopenia y osteoporosis en un grupo de adultos mayores de Quito / Prevalence of osteopenia and osteoporosis in a group of older adults from Quito

La osteoporosis, enfermedad conocida desde hace mucho tiempo ha presentado un desarrollo impresionante en las últimas décadas. El propósito del presente trabajo es determinar la prevalencia de osteopenia y osteoporosis en un grupo de adultos mayores de Quito. Se obtuvieron medidas antropométricas: Peso, talla, índice de masa corporal. Se determinó la densidad mineral ósea mediante ultrasonido a nivel de la muñeca. Se definió como osteopenia a una densidad mineral ósea entre -1 a -2,5 desviaciones estándar y como osteoporosis a un valor menor a -2,5 desviaciones estándar. La prevalencia de osteopenia fue de 31.9%, 36,5% en los hombres y 28,4% en las mujeres, la prevalencia de osteoporosis fue de 19,4%, 12,7% en los hombres y 24,7% en las mujeres. Se encontró una prevalencia elevada de osteoporosis especialmente en las mujeres. La prevalencia de osteoporosis fue mayor en las personas con sobrepeso, excepto en los hombres.

Osteoporosis, a disease known for a long time, has shown an impressive development in the last decades. The purpose of this work is to determine the prevalence of osteopenia and osteoporosis in a group of older adults from Quito. Anthropometric measurements were obtained: Weight, height, body mass index. Bone mineral density was determined by ultrasound at the wrist level. Osteopenia was defined as a bone mineral density between -1 to -2.5 standard deviations and as osteoporosis a value less than -2.5 standard deviations. The prevalence of osteopenia was 31.9%, 36.5% in men and 28.4% in women, the prevalence of osteoporosis was 19.4%, 12.7% in men and 24.7% in women. women. A high prevalence of osteoporosis was found especially in women. The prevalence of osteoporosis was higher in overweight people, except in men.

Sobrepeso y dislipidemias en una institución pública de Quito / Overweight and dislipidemias in a public institution of Quito

La obesidad es un desorden nutricional cuya prevalencia se incrementa a nivel mundial y constituye un factor de riesgo para muchas enfermedades crónicas. El objetivo fue determinar la prevalencia de sobrepeso y dislipidemias en los trabajadores de una institución pública de Quito. Se encontró que un 44,2 por ciento de personas tiene sobrepeso y 7,5 por ciento obesidad. Un 37,5 por ciento de personas tiene hipercolesterolemia y 22,1 por ciento presentan hipertrigliceridemia. Las prevalencias encontradas fueron mayores en los hombres que en las mujeres, excepto la prevalencia de obesidad. La prevalencia de sobrepeso es similar a la reportada en muchos países desarrollados y en algunos países desarrollados y en algunos paises latinoamericanos...