Evolutionary timelines help explain the evolution of parental care strategies.

Comparative research on the evolution of parental care has followed a general trend in recent years, with researchers gathering data on clutch size or egg size and correlating these traits with ecological variables across a phylogeny. The goal of these studies is to shed light on how and why certain strategies evolve. However, results vary across studies, and we rarely have results explaining why the observed pattern occurred, leaving us with further hypotheses to test.

Biomechanical drivers of the evolution of butterflies and moths with a coilable proboscis.

Current biomechanical models suggest that butterflies and moths use their proboscis as a drinking straw pulling nectar as a continuous liquid column. Our analyses revealed an alternative mode for fluid uptake: drinking bubble trains that help defeat drag. We combined X-ray phase-contrast imaging, optical video microscopy, micro-computed tomography, phylogenetic models of evolution and fluid mechanics models of bubble-train formation to understand the biomechanics of butterfly and moth feeding.

Flexural rigidity of hawkmoth antennae depends on the bending direction.

To probe its environment, the flying insect controllably flexes, twists, and maneuvers its antennae by coupling mechanical deformations with the sensory output. We question how the materials properties of insect antennae could influence their performance. A comparative study was conducted on four hawkmoth species: Manduca sexta, Ceratomia catalpae, Manduca quinquemaculata, and Xylophanes tersa.

How seasonality influences the thermal biology of lizards with different thermoregulatory strategies: a meta-analysis.

Ectotherms that maintain thermal balance in the face of varying climates should be able to colonise a wide range of habitats. In lizards, thermoregulation usually appears as a variety of behaviours that buffer external influences over physiology. Basking species rely on solar radiation to raise body temperatures and usually show high thermoregulatory precision.

Wettability and morphology of proboscises interweave with hawkmoth evolutionary history.

Hovering hawkmoths expend significant energy while feeding, which should select for greater feeding efficiency. Although increased feeding efficiency has been implicitly assumed, it has never been assessed. We hypothesized that hawkmoths have proboscises specialized for gathering nectar passively.

Haemolymph viscosity in hawkmoths and its implications for hovering flight.

Viscosity determines the resistance of haemolymph flow through the insect body. For flying insects, viscosity is a major physiological parameter limiting flight performance by controlling the flow rate of fuel to the flight muscles, circulating nutrients and rapidly removing metabolic waste products. The more viscous the haemolymph, the greater the metabolic energy needed to pump it through confined spaces.

The hidden links between animal weapons, fighting style, and their effect on contest success: a meta-analysis.

In many species that fight over resources, individuals use specialized structures to gain a mechanical advantage over their rivals during contests (i.e. weapons).

Flight hampers the evolution of weapons in birds.

Birds are a remarkable example of how sexual selection can produce diverse ornaments and behaviours. Specialised fighting structures like deer's antlers, in contrast, are mostly absent among birds. Here, we investigated if the birds' costly mode of locomotion-powered flight-helps explain the scarcity of weapons among members of this clade.

Biomechanics influence sexual dimorphism in the giant mesquite bug, Thasus neocalifornicus.

In many species, males possess specialized weaponry that confers benefits during male-male combat. Because male weapons are often disproportionately larger versions of preexisting body parts, females often possess reduced versions of male weaponry. Most research focuses exclusively on sexual dimorphism in the size of male and female weapons, even though other aspects such as weapon performance can also explain the evolution of weapon sexual dimorphism.

Supergroup F in terrestrial isopods: Horizontal transmission from termites?

Unlabelled: Horizontal transmission between distantly related species has been used to explain how infect multiple species at astonishing rates despite the selection for resistance. Recently, a terrestrial isopod species was found to be infected by an unusual strain of supergroup F . However, only of supergroup B is typically found in isopods.

Harder, better, faster, stronger: Weapon size is more sexually dimorphic than weapon biomechanical components in two freshwater anomuran species.

Sexual selection influences the evolution of morphological traits that increase the likelihood of monopolizing scarce resources. When such traits are used during contests, they are termed weapons. Given that resources are typically linked to monopolizing mating partners, theory expects only males to bear weapons.

The longer the better: evidence that narwhal tusks are sexually selected.

Once thought to be the magical horn of a unicorn, narwhal tusks are one of the most charismatic structures in biology. Despite years of speculation, little is known about the tusk's function, because narwhals spend most of their lives hidden underneath the Arctic ice. Some hypotheses propose that the tusk has sexual functions as a weapon or as a signal.

Underwater compensation for exaggerated weaponry: The role of morphology and environment on crab locomotor performance.

Exaggerated morphologies may increase fitness, but they might be costly to bear; heavy weight, for instance, might hinder locomotion. Evidence supporting these costs are sparse because animals that move on land or swim have traits reducing those costs, called compensatory traits. Animals that walk underwater, however, are under different environmental pressures than land animals.

All by myself? Meta-analysis of animal contests shows stronger support for self than for mutual assessment models.

Since the 1970's, models based on evolutionary game theory, such as war of attrition (WOA), energetic war of attrition (E-WOA), cumulative assessment model (CAM) and sequential assessment model (SAM), have been widely applied to understand how animals settle contests. Despite the important theoretical advances provided by these models, empirical evidence indicates that rules adopted by animals to settle contests vary among species. This stimulated recent discussions about the generality and applicability of models of contest.

How does environment influence fighting? The effects of tidal flow on resource value and fighting costs in sea anemones.

An animal's decision to enter into a fight depends on the interaction between perceived resource value (V) and fighting costs (C). Both could be altered by predictable environmental fluctuations. For intertidal marine animals, such as the sea anemone , exposure to high flow during the tidal cycle may increase V by bringing more food.

[Impact of quality improvement process upon the state of nutritional support in a critical care unit].

Introduction: In a preceding article the state of Nutritional support (NS) in an Intensive Care Unit (ICU) was documented [Martinuzzi A et al. Estado del soporte nutricional en una unidad de Cuidados críticos. RNC 2011; 20: 5-17].