Plastic and genomic change of a newly established lizard population following a founder event.

Understanding how phenotypic divergence arises among natural populations remains one of the major goals in evolutionary biology. As part of competitive exclusion experiment conducted in 1971, 10 individuals of Italian wall lizard (Podarcis siculus (Rafinesque-Schmaltz, 1810)) were transplanted from Pod Kopiste Island to the nearby island of Pod Mrcaru (Adriatic Sea). Merely 35 years after the introduction, the newly established population on Pod Mrcaru Island had shifted their diet from predominantly insectivorous towards omnivorous and changed significantly in a range of morphological, behavioural, physiological and ecological characteristics. Here, we combine genomic and quantitative genetic approaches to determine the relative roles of genetic adaptation and phenotypic plasticity in driving this rapid phenotypic shift. Our results show genome-wide genetic differentiation between ancestral and transplanted population, with weak genetic erosion on Pod Mrcaru Island. Adaptive processes following the founder event are indicated by highly differentiated genomic loci associating with ecologically relevant phenotypic traits, and/or having a putatively adaptive role across multiple lizard populations. Diverged traits related to head size and shape or bite force showed moderate heritability in a crossing experiment, but between-population differences in these traits did not persist in a common garden environment. Our results confirm the existence of sufficient additive genetic variance for traits to evolve under selection while also demonstrating that phenotypic plasticity and/or genotype by environment interactions are the main drivers of population differentiation at this early evolutionary stage.

Relationships between dietary breadth and flexibility in jaw movement: A case study of two recently diverged insular populations of Podarcis lizards.

The kinematics of lizard feeding are the result of complex interactions between the craniocervical, the hyolingual, and the locomotor systems. The coordinated movement of these elements is driven by sensory feedback from the tongue and jaws during intraoral transport. The kinematics of jaw movements have been suggested to be correlated with the functional characteristics of the prey consumed, such as prey mobility and hardness. However, whether and how dietary breadth correlates with the flexibility in the behavioral response has rarely been tested, especially at the intraspecific level. Here we tested whether an increase in dietary breadth was associated with a greater behavioral flexibility by comparing two recently diverged populations of insular Podarcis lizards differing in dietary breadth. To do so, we used a stereoscopic high-speed camera set-up to analyze the jaw kinematics while offering them different prey types. Our results show that prey type impacts kinematics, especially maximum gape, and maximum opening and closing speed. Furthermore, the behavioral flexibility was greater in the population with the greater dietary breadth, suggesting that populations which naturally encounter and feed on more diverse prey items show a greater ability to modulate their movements to deal with variation in functionally relevant prey properties. Finally, the more generalist population showed more stereotyped movements suggesting a finer motor control.

La anorexia: consideraciones socioeconómicas y concepciones psicoanalíticas / The anorexia: socioeconomic considerations and psychoanalytic conceptions

¿Es la anorexia una problemática actual? ¿Es un fenómeno que está de moda? ¿Por qué tantos intentos de abordaje y tan pocos resultados? Éstas y muchas otras cuestiones son las que emergen ante el estallido de la casuística y con la cantidad de abordajes y concepciones que ello ha traído consigo. De un lado, de la mano de la publicidad y los ideales estéticos de belleza, se piensa en el impacto sin igual de la lógica del consumo sin reservas anudada a la circulación de imágenes de lo que se considera esbelto dentro de lo social; de otro, se apela a explicaciones de orden psicológico y psíquico que consideran el efecto de la presencia hostigante de una madre que avasalla el deseo de su hija y con ello instaura en ésta una relación caótica con la ingesta y con la vivencia de la feminidad, o suponen una contemporaneidad que promueve la circulación abierta e incontenida de las formas singulares de gozar de los seres hablantes, lo que trae como efecto modificaciones y novedades en las maneras de hacer vínculo y establecer sociedad. Este panorama suscita el intento de esclarecer y establecer los posibles límites y dificultades a que ha dado lugar lo que se ha dicho acerca de la anorexia en los contextos socioeconómico y clínico psicoanalítico ­sin desconocer lo histórico del fenómeno­ y que este texto busca recoger en sus principales puntos.

Is anorexia currently an issue? Is it a trendy phenomenon? Why are there so many approaches and so few results? These and many other concerns have been raised by the outbreak of cases recorded and the many approaches and definitions brought by it. On one hand, thanks to advertising and the aesthetic standards of beauty, we analyze the great impact of consumption logic without measure tied to the spreading of images of what's considered svelte; on the other hand, we have the psychological and psychic explanations that considers the effect of the presence of a lashing mother that subdues her daughter's desire, which establishes a chaotic relationship with the consumption of food and the experience of femininity, or supposes that our contemporaneity promotes the open and unrestrained flow of ways for jouissance of the speaking beings, that result in modifications and innovations in the ways we relate to each other and build society. This scene calls for an attempt to clarify and establish the possible limits and obstacles found in what's been said about anorexia in the socioeconomic, and clinical-psychoanalytical contexts ­without ignoring the historical grounds of the phenomenon­ and that this article pretends to condense through its key points.