A multidimensional perspective on the role of behavior in evolution

Behavior determines how organisms interact with their environment, and has long been posited as a pacemaker for evolution. The classical view is that novel behaviors expose organisms to new selective pressures, in turn "driving" evolution. Behavior can also restrain evolutionary change. Some behaviors, such as thermoregulation, help organisms maintain a constant selective environment, thus "inhibiting" evolution. This thesis seeks to understand the role of behavior in influencing the evolutionary process. In the first part, I test the hypothesis that the same behavior can simultaneously impede and impel evolution in different traits. I focus on the lizard, Anolis cybotes, from the Caribbean island of Hispaniola. Through a replicated field experiment I show that behavioral flexibility allows these lizards to maintain a constant body temperature in markedly different thermal habitats. I determine that this similarity in body temperatures is associated with physiological stasis, as the preferred temperature and heat tolerance are nearly identical among populations. I demonstrate that the behavioral change allowing lizards to maintain a constant body temperature involves a perch switch. Finally, I demonstrate that this shift in structural habitat use from trees at low elevation to rocks at high elevation in turn impels morphological evolution in traits associated with rock use, and that these traits are likely genetically based. Thus, a perch switch to rocks at high elevation is simultaneously impeding physiological evolution, whilst impelling morphological evolution. In the second part of my study, I asked whether rates of evolution differ among physiological traits, and how thermoregulation influences these rates. I found that cold tolerance evolves significantly faster than heat tolerance in the cybotoid anoles, a clade of anoles that contains A. cybotes and its relatives. I demonstrate that thermal variation is considerably greater during the day than at night and, at high elevation, nighttime temperatures are so cold that they would incapacitate most lizards. In the absence of thermal refuges and behavioral buffering, lizards at high elevation have no choice but to adapt their physiology. Thus, the ability to thermoregulate during, but not at night, likely influences differences in rates of evolution between heat and cold tolerance

A multidimensional perspective on the role of behavior in evolution

Behavior determines how organisms interact with their environment, and has long been posited as a pacemaker for evolution. The classical view is that novel behaviors expose organisms to new selective pressures, in turn "driving" evolution. Behavior can also restrain evolutionary change. Some behaviors, such as thermoregulation, help organisms maintain a constant selective environment, thus "inhibiting" evolution. This thesis seeks to understand the role of behavior in influencing the evolutionary process. In the first part, I test the hypothesis that the same behavior can simultaneously impede and impel evolution in different traits. I focus on the lizard, Anolis cybotes, from the Caribbean island of Hispaniola. Through a replicated field experiment I show that behavioral flexibility allows these lizards to maintain a constant body temperature in markedly different thermal habitats. I determine that this similarity in body temperatures is associated with physiological stasis, as the preferred temperature and heat tolerance are nearly identical among populations. I demonstrate that the behavioral change allowing lizards to maintain a constant body temperature involves a perch switch. Finally, I demonstrate that this shift in structural habitat use from trees at low elevation to rocks at high elevation in turn impels morphological evolution in traits associated with rock use, and that these traits are likely genetically based. Thus, a perch switch to rocks at high elevation is simultaneously impeding physiological evolution, whilst impelling morphological evolution. In the second part of my study, I asked whether rates of evolution differ among physiological traits, and how thermoregulation influences these rates. I found that cold tolerance evolves significantly faster than heat tolerance in the cybotoid anoles, a clade of anoles that contains A. cybotes and its relatives. I demonstrate that thermal variation is considerably greater during the day than at night and, at high elevation, nighttime temperatures are so cold that they would incapacitate most lizards. In the absence of thermal refuges and behavioral buffering, lizards at high elevation have no choice but to adapt their physiology. Thus, the ability to thermoregulate during, but not at night, likely influences differences in rates of evolution between heat and cold tolerance

El turismo y sus impactos: Actitudes y percepciones de las poblaciones locales

El turismo actualmente constituye un intrincado entramado de procesos socioeconómicos, que van desde la construcción imaginaria de los destinos como lugares de recreo y esparcimiento, hasta las prácticas de implantación neocolonial de la industria turística, pasando por el cambio en las estructuras de la propiedad del suelo y de los recursos locales, la transformación radical de los territorios, de las formas de estratificación social, del mercado y de los modos de trabajo o bien, de la distribución del ingreso. Complejo entramado que es, a la vez un campo donde se intercambian distintos tipos de capital y se altera su composición, su distribución y volumen y, una arena político económica donde dirimen sus diferencias grupos de poder, facciones, partidos políticos e intereses contrapuestosEl interés en el turismo y sus impactos como objeto de estudio lleva cuatro décadas. Durante todo este tiempo, se ha avanzado considerablemente en la perspectiva que identificara los impactos del turismo a través de la percepción de las sociedades receptoras y con ello conocer las actitudes de éstas hacia el turismo y los turistas. En esta empresa se han hecho diversas aportaciones en el terreno de la metodología que permitiera su comprensión. El trabajo que aquí se presenta tiene por finalidad presentar una revisión sobre cómo se han estudiado los impactos, las percepciones y las actitudes de las poblaciones receptoras hacia el turismo

Mujeres y sus representaciones sociales de género en el CIP Bahías de Huatulco, México

En este trabajo se exponen los resultados de un estudio que buscó conocer si la representación social de la mujer se ve modificada por el hecho de vivir o trabajar en un contexto turístico. Gracias al uso de entrevistas a profundidad, se obtuvo que el turismo proporciona a las mujeres la posibilidad de integrarse a la vida laboral remunerada y permite el contacto con hombres y mujeres cuyas conductas no se asemejan a las conductas de los habitantes de las zonas turísticas. Los roles modificados o nuevos pueden dar origen a una percepción del yo individual, que se transmite al yo colectivo y, por tanto, incide en la modificación de la memoria colectiva. Dicha resignificación de la representación social de la identidad de género implica el proceso por el cual las mujeres buscan dejar de ser cosas o seres-en-sí, para caminar hacia la posibilidad de ser sujetos.PROMEP- SE

Comparative Phylogeography of Two Seastars and Their Ectosymbionts Within the Coral Triangle

Repeated exposure and flooding of the Sunda and Sahul shelves during Pleistocene sea level fluctuations is thought to have contributed to the isolation and diversification of sea basin populations within the Coral Triangle. This hypothesis has been tested in numerous phylogeographic studies, recovering an assortment of genetic patterns that the authors have generally attributed to differences in larval dispersal capability or adult habitat specificity. This study compares phylogeographic patterns from mitochondrial COI sequences among two co-distributed seastars that differ in their adult habitat and dispersal ability, and two seastar ectosymbionts that differ in their degree of host specificity. Of these, only the seastar Linckia laevigata displayed a classic pattern of Indian-Pacific divergence, but with only moderate genetic structure (ΦCT = 0.067). In contrast, the seastar Protoreaster nodosus exhibited strong structure (ΦCT = 0.23) between Teluk Cenderawasih and the remainder of Indonesia, a 12 pattern of regional structure that was echoed in L. laevigata (ΦCT = 0.03) as well as its obligate gastropod parasite Thyca crystallina (ΦCT = 0.04). The generalist commensal shrimp, Periclimenes soror showed little genetic structuring across the Coral Triangle. Despite species-specific phylogeographic patterns, all four species showed departures from neutrality that are consistent with massive range expansions onto the continental shelves as sea levels rose, and date within the Pleistocene epoch. Our results suggest that habitat differences may affect the manner in which species responded to Pleistocene sea level fluctuations, shaping contemporary patterns of genetic structure and diversity

Espacio Publico en lo Rural: "espacio publico como generador de usos alternativos para la comunidad"

80 p.Qué pasa con el territorio en que vivimos, ese territorio de hermoso paisaje que tiene vida por sí solo y este escondido en lugares donde lo moderno año no lo alcanza, lugares sin decisiones tomadas, lugares muchas veces olvidados, donde el ser humano con su trabajo y sus costumbres, nos reflejan una crónica de vida. La vida de algunas personas trascurren en pequeños caseríos que aparecen al lado de un camino, dejando en evidencia la labor campesina, a través de faenas agrícolas, pueblos donde se vive a diario Ia tradición, una cultura campesina; pequeñas "zonas intermedias", que aparecen entre plantaciones, viñedos, etc. donde las personas se relacionan y generan un sentimiento de comunidad y un vínculo del hombre con su entorno natural; esta interrelación se refleja a través de la apropiación y transformación de espacios residuales, que son utilizados para Ia recreación y circulación, sea de manera permanente o temporal. Todo esto se asocia al concepto de identidad de una comunidad, que debería generar condiciones hacia el desarrollo sostenible que deberían tener cada uno de los caseríos que se encuentran en Ia región

Zinc combined with vitamin A reduces upper respiratory tract infection morbidity in a randomised trial in preschool children in Indonesia

Zn supplementation has shown inconsistent effects on respiratory morbidity in young children in developing countries. Few studies have focused on upper respiratory tract infection (URTI), a frequent cause of morbidity in this group, and potential benefit from Zn supplementation or factors that influence its efficacy. We investigated the effects of Zn supplementation on URTI before and after vitamin A supplementation. This randomised double-blinded controlled Zn supplementation study was conducted on 826 children aged 2–5 years. Placebo or Zn (10 mg/d) was given in syrup daily for 4 months, with 200 000 IU vitamin A (60 mg retinol) given to all children at 2 months. Health workers visited children every 3 d for compliance and morbidity information. We found that 84 % of children experienced URTI during the study. Zn supplementation reduced the percentage of days with URTI (12 % reduction; P = 0·09), with greater impact following vitamin A supplementation (20 % reduction; P = 0·01). Vitamin A supplementation was associated with a decreased number but an increased duration of URTI episodes. We conclude that Zn combined with vitamin A supplementation significantly reduced the percentage of days with URTI in a population of preschool Indonesian children with marginal nutritional status. The results suggest that vitamin A status modifies the efficacy of Zn supplementation on URTI

Human Glia Can Both Induce and Rescue Aspects of Disease Phenotype in Huntington Disease

The causal contribution of glial pathology to Huntington disease (HD) has not been heavily explored. To define the contribution of glia to HD, we established human HD glial chimeras by neonatally engrafting immunodeficient mice with mutant huntingtin (mHTT)-expressing human glial progenitor cells (hGPCs), derived from either human embryonic stem cells or mHTT-transduced fetal hGPCs. Here we show that mHTT glia can impart disease phenotype to normal mice, since mice engrafted intrastriatally with mHTT hGPCs exhibit worse motor performance than controls, and striatal neurons in mHTT glial chimeras are hyperexcitable. Conversely, normal glia can ameliorate disease phenotype in transgenic HD mice, as striatal transplantation of normal glia rescues aspects of electrophysiological and behavioural phenotype, restores interstitial potassium homeostasis, slows disease progression and extends survival in R6/2 HD mice. These observations suggest a causal role for glia in HD, and further suggest a cell-based strategy for disease amelioration in this disorder

Dinámica del Consumo de Gasolina en Ciudad Juárez, Chihuahua

This research analyzes short-run gasoline consumption dynamics in Ciudad Juárez, Chihuahua, México. Parameter estimation is carried out using linear transfer function ARIMA analysis. This market is of interest because it is influenced by regional, national, and international economic conditions due to its location on the border with the United States. Explanatory variables that satisfy the significance criterion include the real price of gasoline in Ciudad Juárez, the price of gasoline in Ciudad Juárez relative to that charged across the border in El Paso, Texas, USA, and formal sector employment in Ciudad Juárez. Out-of-sample simulations indicate that the model is relatively accurate for forecasts of to 1 to 24 months into the future

a cross-sectional study

Objectives We determined the seroprevalence and correlates of Toxoplasma gondii infection in pregnant women in Aguascalientes City, Mexico. Design A cross-sectional survey. Setting Pregnant women were enrolled in the central Mexican city of Aguascalientes. Participants We studied 338 pregnant women who attended prenatal care in 3 public health centres. Primary and secondary outcome measures Women were examined for IgG/IgM antibodies to T. gondii by using commercially available enzyme immunoassays, and an avidity test. Multiple analyses were used to determine the association of T. gondii seropositivity with the characteristics of the pregnant women. Results Of the 338 pregnant women studied, 21 (6.2%) had IgG antibodies to T. gondii, and 1 (4.8%) of them was also positive for IgM antibodies to T. gondii. Avidity of IgG antibodies to T. gondii was high in the IgM-positive sample. Logistic regression analysis of sociodemographic, behavioural and housing variables showed that T. gondii seropositivity was associated with white ethnicity (OR=149.4; 95% CI 10.8 to 2054.1; p<0.01), not washing hands before eating (OR=6.41; 95% CI 1.73 to 23.6; p=0.005) and use of latrine (OR=37.6; 95% CI 4.63 to 306.31; p=0.001). Conclusions Results demonstrate that pregnant women in Aguascalientes City have a low seroprevalence of T. gondii infection. However, this low prevalence indicates that most pregnant women are at risk for a primary infection. Factors associated with T. gondii exposure found in this study, including food hygiene, may be useful to determine preventive measures against T. gondii infection and its sequelae