Summary: Milinkovitch et al. (2013)

Many amniotes (an animal possessing an amnion - sac enclosing the developing embryo) show keratinization of various skin appendages, such as hair, feathers and scales. These different appendages differentiate during embryonic development. The differentiation is genetically controlled by developmental units and reaction-diffusion mechanisms (RDMs) pattern the spatial organisation of these units. Milinkovitch et al. (2013) demonstrate that the face and jaw scales of crocodiles do not form under the influence of these genetically controlled elements. Rather, they are random polygonal domains of highly keratinized skin that form by cracking of the skin in a stress field (a physical self-organizing stochastic process). They suggest that this occurs because the embryonic facial and jaw skeleton undergoes rapid growth and is highly keratinized, which generates the mechanical stress that induces cracking.

Summary: Benedict et al. (2012)

Animals often signal at low frequency or with harsh sounds to indicate aggression. For some species, larger body size is correlated with lower frequency sound production and can potentially indicate fighting ability. Low frequency and harsh sounds may also indicate motivation to be aggressive and to attack. Benedict et al. (2012) investigated whether canyon wrens Catherpes mexicanus alter vocal behaviour (facultative adjustment) in the low frequency range, and whether they utter more harsh calls, in response to territorial intrusions (playback simulations). They found that territory holders altered their song type usage, lowered their frequency and increased song production rate in response to simulated intrusions. Territory holders were also more likely to attach harsh notes to the ends of songs. Benedict et al. (2012) indicate that these results support the motivation-structural hypothesis.

Summary: Mainwaring & Hartley (2013)

Individuals vary in behaviour. While the evolutionary and ecological consequences of this variation have been relatively well studied, the causes remain unknown. One of the primary influences of offspring behavioural development are the parents, which exert the majority of influence during the pre- and early post-natal periods. Female zebra finches Taeniopygia guttata, as for many other bird species, will hatch asynchronous clutches when females initiate incubation prior to completing laying. This drives differences in phenotypic expression between early and late-hatched young. Mainwaring & Hartley (2013) manipulated the hatching patterns of zebra finches and found that late-hatched birds from asynchronous clutches were bolder, exploring a novel environment more, than their earlier hatched or synchronous hatched siblings. They also noted sex differences in exploration of a novel object, with females being bolder than males, regardless of hatching regime. Mainwaring & Hartley's (2013) study provide support that variations in an offspring's early environment can have a significant influence on the expression of its behaviour and provides an insight into how parental investment plays a role in maintaining and generating behavioural variation.

Summary: Padmanabhan et al. (2012)

Transcriptional feedback loops drive the functioning of eukaryotic circadian clocks. Two important mammalian proteins involved in this process are Period (PER) and Cryptochrome (CRY). These proteins aggregate and form large nuclear complexes (PER complex), suppressing their own transcription. Padmanabhan et al. (2012) found the RNA helicases DDX5 and DHX9 are included in the PER complexes of mice. In addition, other molecules, such as RNA polymerase II large subunit, were also located here, promoting the termination of transcription. They found that RNA polymerase II accumulates, during circadian negative feedback, near termination sites on Per and Cry genes, but it does not control these genes. They conclude that this negative feedback mechanism includes direct control of the termination of protein transcription.

Summary: Stamatakis & Stuber (2012)

Negative reward-related information is carried to the ventral portion of the middle brain (including the rostromedial tegmental nucleus) via projections of the lateral habenula. Stamatakis & Stuber (2012) studied the behavioural complications of selective activation of this particular pathway in the brain in mice. They found that aversive stimuli increased the excitatory drive of the lateral habenula, which resulted in conditioned, passive and active behavioural avoidance of the aversive stimulus. The activity of these projections to the midbrain is thus aversive, and functions to negatively reinforce behavioural response.

Summary: Markham et al. (2012)

Social species benefit from group living, however, social groups must also compete for resources with other groups. Competition can be a major driver influencing a group's movements and space use and has the potential to shape the evolution of sociality. Markham et al. (2012) investigated the ecological factors influencing baboon Papio cynocephalus group dominance, with a specific focus on what spatial features influence dominance and what occurs when a group is defeated. They found that the number of adult males in a group predicted which group would win a direct conflict, but they also found that a group's intensity of use of areas associated with the encounter location also predicted a win, over a longer time period (9-12 months). Losing groups  used the area surrounding the encounter location less, possibly incurring short-term costs associated with reduced access to resources. Markham et al.'s (2012) study highlights the importance of inter-group competition on social group space use.

Summary: Kronfeld-Schor et al. (2013)

The circadian "clock" is the body's internal mechanism for keeping track of time. This "clock" is driven by an individual's physiology and it influences an animal's behaviour on a daily basis. Alterations to environmental light conditions results in the natural time-keeping rhythms to become entrained to particular light-dark (day-night) cycles. The circadian system consists of molecular, cellular, tissue and organismal levels, and how these levels contribute to an individuals behaviour is quite well understood. The shortcomings of these studies relate to the species studied, typically those that are standard laboratory species that have been maintained in captivity (so called "model" organisms). Kronfeld-Schor et al. (2013) suggest that to understand the evolutionary significance of the circadian clock, we need to study a variety of species from multiple taxonomic groups that display a diversity in activity patterns (e.g. diurnal, nocturnal, cathemeral, crepuscular). In a special feature of the Proceedings of the Royal Society of London B, Kronfeld-Schor et al. (2013) highlight seven papers that attempt to explore the adaptive significance of the circadian clock, with the reviews including the influence of moonlight, latitude, evolutionary history, sociality, temporal niche specialization, annual variation and post-transcriptional mechanisms. These seven papers demonstrate the complexity, as well as the diversity, of the circadian system.

Summary: Madden & Whiteside (2013)

Females of many species show individual differences in their choice of mate, which has subsequent effects on fitness. These choices are shaped by early life experiences. Madden & Whiteside (2013) studies how adult sexual behaviour of pheasants Phasianus colchicus is influenced by the sex ratio of the clutch at rearing. When females are raised in equal sex ratio clutches, they showed a strong discrimination between males of different attractiveness, while females raised in female-biased clutches did not discriminate between males. These females also showed highly skewed mating success, with most achieving no copulations and relatively few gaining the most. Madden & Whiteside (2013) suggest that the early life environment could influence variation in female mate choice, which could ultimately maintain male trait variation that is otherwise under strong direction selection.

Summary: McNamara et al. (2013)

Animals are able to evaluate the word in relative terms through successive contrast effects. These behaviours are dependent on the state of the current conditions (better or worse) in relation to previous conditions. Generally, descriptive models of various processes (psychological and physiological) attempt to explain these effects. The factors promoting the evolution of these contrast effects has been relatively poorly studied. McNamara et al. (2013) used simple and general optimality models to show that adaptive responses to uncertainty result in contrast effects in an environment that is dynamic and unpredictable. They suggest that sensitivity to past conditions will be selected for by a wide range of environmental change patterns, which can generate either positive or negative contrast effects. Based on these findings, McNamara et al. (2013) they suggest that environmental stochasticity and uncertainty should be included into future adaptive behaviour models.

Summary: Allen et al. (2013)

Neornithes (living birds) locomote by feather-aided flight and they have a bipdeal crouched hindlimb support structure that facilitates walking / running. The evolution of both these traits is controversial, however, computer modelling and well preserved specimens are paving the way for identifying the underlying biomechanics of locomotion. Allen et al. (2013) digitally reconstructed the body morphology of species across the Archosauria clade (17 species), using three-dimensional reconstruction of body shape, to measure the trends in evolutionary locomotor biomechanics. Species used included the four major species representing major key stages in avian body plan evolution: Microraptor, Archaeopteryx, Pengornis and Yixianornis. Allen et al. (2013) suggest that a more-crouched limb posture was acquired gradually in a step-wise fashion through theropod evolution, although this was accelerated in the Maniraptoran clade. They also found that enlargement of the pectoral limb, with other associated trends, had a stronger influence on the evolution of hindlimb posture than tail reduction. Within the Manirapotra, Allen et al. (2013) also found that the evolution of flight is closely correlated with the accelerated morpho-functional trends observed. They suggest that anatomical novelties in the pelvic and pectoral limbs is closely linked to the evolution of flight in birds.

Summary: Liu et al. (2012)

Prolonged social isolation results in stress, particularly in group-living species. Isolation stress, particularly during the early developmental period, may then have a profound influence on cognitive and endocrine function, as well as behaviour. Liu et al. (2012) found that prolonged social isolation also influenced transcriptional and structural alterations to neurons in the prefontal cortex. They also found that re-integration with the social group normalized transciptional and behavioural changes. In addition, they noted that shorter periods of isolation did not induce behavioural change, but did influence structure of chromatin and myelin. Liu et al. (2012) suggest that the alteration of myelination in response to social interactions could be a form of phenotypic plasticity in adults.

Summary: Byers & Dunn (2012)

 Male male competition and female mate choice are two aspects of sexual selection. In the case of male-male competition, the advantage of a competitor is largely determined by his fecundity, that is, the number of offspring he sires. Angus Bateman characterised this interaction in the form of a quantitative relationship known as the Bateman slope. This slope graphically depicts the relationship between a male's number of mates and the number of offspring produced. The potential for sexual selection is estimated from the slope of the line. Male mating success often relies on sexual dimorphism, and males with larger (heavier etc). traits are likely to achieve more matings. Generally, sexual dimorphism requires a positive Bateman slope. However, natural selection and random effects may also influence a male's ability to win mates. Byers & Dunn (2012) found a yearly positive Bateman slope for pronghorn Antilocapra americana over a decade, with no indication that random effects were skewing male mating success. They did find that there was variation between years due to fawn predation. Byers & Dunn (2012) suggest that environmental and/or extrinsic factors could limit sexual selection potential, but in general, the validity of a positive Bateman relationship is supported.

Summary: Corcoran et al. (2009)

 It has been hypothesized that the ultrasonic clicks made by some moth species in the presence of bats either warn bats of moth toxicity (aposematic signalling), startle bats that are not accustomed to sonic prey or are used to "jam" the bats echolocating signal. Tiger moths Bertholdia trigona are known to make ultrasonic clicks in response to the sonar clicks of some bats, such as big brown bats Eptesicus fuscus. Corcoran et al. (2009) studied which of these hypotheses is most likely for tiger moths using ultrasonic recording and high-speed infrared videography when moths interacted with bats. They found that tiger moths ultrasonic clicking jams big brown bat sonar. Sonar jamming has likely evolved in an evolutionary arms race between bats and insects.

Summary: Ortega-Jimenez & Dudley (2013)

The microstructure and ornamentation of spider webs influences their capture success. Furthermore, wind-induced vibrations may also influence capture success. Ortega-Jimenez & Dudley (2013) investigated whether positively electrostatically charged insects (honeybees Apis mellifera, green bottle flies Lucilia sericata, fruit flies Drosophila melanogaster, aphids Aphidoide) and water droplets influenced cross-spider Araneus diadematus web deformation as evidence has suggested that silk thread is attracted to electrostatically charged objects. Ortega-Jimenez & Dudley (2013) found that these electrostatically charged objects caused rapid deformation of spider thread, which they suggest could increase the risk of capture of flying prey.

Summary: Melichar & Robovský (2012)

Melichar & Robovský (2012) observed a novel defence group formation in captive golden takin Budorcas bedfordi, an ungulate that shares common features with the muskox Ovibos moschatus. A single day of occurrence of this behaviour was recorded in response to enclosure sharing with Chinese muntjacs Muntiacus reevesi. The formation was similar to that observed in wild muskox and rotated according to individual muntjac movement within the enclosure. The takin also emitted loud vocalisations and made several lunge attempts towards the muntjacs, although no direct contact was observed. This behaviour was exhibited multiple times on one day, but was not observed thereafter. Muntjacs actively avoided takin during this period, whereafter they entered the takin enclosure with limited interference. The takin thereafter ignored the muntjacs, although occasionally snorting was observed. Melichar & Robovský (2012) suggest that this behaviour has not be observed in wild takin. Due to its phylogenetic relationship with muskox, it is likely either that this behaviour evolved independently in the two groups, or occurred in a distant caprine ancestor.

Summary: Burgevin et al. (2013)

 The observation of same-sex sexual behaviour is common and taxonomically widespread. It is particularly observed in the insects, including the seed beetle Callosobruchus maculatus. While the focus of most research efforts have been on male-male same sex behaviour, some studies have started to investigate female-female same sex behaviour. The current theory behind male-male same sex behaviour is that the males accrue benefits associated with high mating rate, but that males are also poorly adept at discriminating between the sexes. This cannot explain female-female same behaviour as females do not typically mount males when mating. Burgevin et al. (2013) used a full-sib design and found that variation in male-male mount in the seed beetle explained a high proportion of the variation in female-female mounting behaviour, indicating an intersexual correlation. Their findings did not support that same-sex behaviour is related to activity or was costly for females. Burgevin et al. (2013) suggest that, at least for seed beetles, female-female same sex behaviour carries only a low cost and is maintained via selection on males in the population.

Summary: Krane et al. (2003)

The Indonesian prosimian, the slow loris Nycticebus coucang are known to inflict painful (occasionally fatal) bites that elicit anaphylaxis. The "venom" originates in the brachial organ. This organ is located in a naked area of skin on the inner arm surface. Krane et al. (2003) isolated a 18kDA protein (two 70-90 amino-acid chains with linking disulphide bonds) from the brachial organ. The N-termini of the protein chains were similar to an allergen from common house cats Felis catus, Fel d 1, suggesting the they exhibit inorganic cross- reactivity. This, together with the display of anaphylaxis and increased sensitivity to slow loris bites indicates that this slow loris protein is an allergen.

Summary: Maia & Volpato (2013)

The colour of environmental light can influence the stress-induced cortisol response observed in fish. Maia & Volpato (2013) investigated the effects of three (blue, yellow, white) environmental light colours on the stress response (changes in ventilatory frequency) of Nile tilapia Oreochromis niloticus to confinement. They found that, after 7 days, fish ventilatory frequency was similar under each environmental colour. Similarly, after a 15 minute period of confinement, ventilatory frequency increased, regardless of environmental colour, in the first period (0-4 minutes). Interestingly, Maia & Volpato (2013) found that, irrespective of time, fish kept under white light showed a higher post-confinement ventilatory frequency compared to fish kept under blue light. They suggest that Nile tilapia should be maintained under blue light to minimize stress.

Summary: Brown & Brown (2013)

Erickson et al. (2005) estimate that 80 million birds in the U.S. are killed annually by vehicles. Over a 30 year period, Brown & Brown (2013) found that there was a sharp decline in the incidence of road-kill in cliff swallows Petrochelidon pyrrhonota. Individuals cliff swallows that were killed on roads had longer wings than the average seen in the overall population. Longer wings could mean lower wing loading and inhibition of vertical take-off, resulting in these birds experiencing increased mortality. Alternatively, birds could be learning to avoid vehicles. Brown & Brown (2013) suggest that road mortality could be driving species response to change and could also exert selection for traits minimising collision.

Summary: Franz & Goldstein (2013)

Recently, Deans et al. (2012) proposed that philosophical descriptions of phenotypes can be used to pave the way in systematics and taxonomy. Franz & Goldstein (2013), while welcoming their contribution, question their approach.

Summary: Szyf (2013)

Szyf (2013) highlights the widely recognized, but poorly understood, concept of gene-environment interaction. Gene-environment interactions were first identified by epidemiologists who noted that a risk allele for increased lifetime risk of suffering from a disease is influenced by the particular environment an individual occurs in. The question still remains: How do genes and environments interact? Szyf (2013) provides a commentary on the report of Klengel et al. (2013) identifying the molecular mechanism of post-traumatic stress disorder (PTSD). Klengel et al. (2013) identified demethylation in the stress response regulator FKBP5 of a glucocorticoid response element that depends on both childhood trauma and the underlying allele.

Summary: Zaher & Riad (2012)

 Zaher & Riad (2012) noted that there is a unique median transitory cartilaginous precarotid plate in Pterocles alchata caudacutus that forms a floor to the hypophyseal fenestra in the posterior orbital region of the intermediate developmental embryo. The anterior pater is homologous to the precarotid commisure of some birds, however, its homology to the taenia intertrabecularis of some reptiles and birds is questioned.

Summary: Cresswell & Thompson (2012)

Cresswell & Thompson (2012) provide a technical comment to Henry et al's (2012) report "A Common Pesticide Decreases Foraging Success and Survival in Honey Bees". In this report, Henry et al. (2012) designed a model to predict that pesticide-induced intoxication by thiamethoxam, a neonicotinoid systemic pesticide, disrupts navigation, resulting in colony collapse (although it must be noted here that Henry et al. 2012 do not state explicitly in their article that a colony will collapse, but rather that it may be at risk of collapse). Cresswell & Thompson (2012) show that collapse disappears under a recalculated model where parameter values are set appropriate to the season during which most flowering crops, that are treated with pesticide, bloom.

Summary: Weygoldt & Huber (2012)

The undescribed whip scorpion Thelyphonus c.f. caudatus from Lombok Indonesia shows similar courtship, sperm transfer and spermatophore type to two other species, T. caudatus and T. linganus. However, Weygoldt & Huber (2012) observed differences in the intromittend tip of the sperm package and maternal care. The intromittend tip of the sperm package is short and wide, with a ring circumventing the opening. While maternal care is initially similar to that of most other Thelyphonidae species, the pre- and protonymphs of T. c.f. caudatus ride on the female's back (riding lasts for an additional for four/five weeks), whereas only the prenymphs ride on the mother's back in the other species. The protonymphs do not feed, persisting on yolk reserves. Maternal care ends when the nymphs do not return from nightly excursions.

Summary: Wilson & Krause (2012)

There has recently been a surge of interest in animal personality. Yet, how and why animal personalities arise, their adaptive significance and consistency of traits across ontogeny remain relatively poorly understood. Similarly, the underlying developmental processes governing metamorphosis remain poorly understood and under-appreciated. Wilson & Krause (2012) suggest that animals that undergo metamorphosis represent a unique opportunity to study the physiological, morphological and ecological influences on personality differences throughout the process of development.

Summary: Lum & Clevers (2012)

In 2012, a small molecule called LGK974, targeting Wnt-mediated cellular signalling entered the first stage of clinical trials. This type of cellular signalling is important in animal development and tissue homeostasis and, as a result, has been identified as a high-priority anticancer drug target. The target of LGK974 is an acyltransferase called Porcupine (PORCN), which adds fatty acids to Wnt. PORCN is a member (the founder) of the 16-gene family that has predicted acyltransferase activity. The fatty acid modification of Wnt is essential to the activity of proteins coded by PORCN. Lum & Clevers (2012) suggest that the proposed use of a PORCN inhibitor for targeting the Wnt signalling pathway in cancer reflects a growing confidence in the use of non-traditional anti-cancer treatments that target  cellular processes important in embryonic development.

Summary: Francis et al. (2002)

It has long been known that maternal care variations in adult rats are associated with changes in neurochemistry and behaviour. When rats receive higher levels of maternal care behaviour as pups, they are less fearful as adults and tend to show higher levels of maternal behaviour themselves. It has been suggested that both oxytocin and vasopressin are important in the expression of anxiety and social behaviour. Francis et al. (2002) assessed whether the variations observed in maternal care behaviour were associated with differences in both oxytocin and vasopressin receptors in adult offspring brains. Oxytocin binding was increased in adult females (in both the central nucleus of the amygdala and the bed nucleus of the stria terminalis) that received higher levels of maternal care as pups. The same response was not observed in adult males. Francis et al. (2002) did, however, find that amygdala vasopressin increased in adult males that received higher levels of maternal care as pups and, again, this response was sex-specific. They suggest that maternal care influences the expression of oxytocin and vasopressin receptors in a sex-specific manner.

Summary: Kreysing et al. (2012)

Vertebrate retinae are diverse, but, in general, are specialised either to maximise the amount of light hitting the retina (increased number of rods) or to enhance visual acuity (increased number of cones). Kreysing et al. (2012) noted a different functional type of retinae in elephantnose fish (Gnathonemus petersii) that is optimised for neither purpose. They found that cone photoreceptors group together in "reflecting, photonic crystal-lined cups" and these act as macroreceptors. In contrast, they found that rod photoreceptors occur behind these reflector cups, not in them. Interestingly, this arrangement matches photoreceptor sensitivity and allows for detecting mixed-colour stimuli and the grouping of these photoreceptor cells results in insensitivity to spatial noise. These allow for a more reliable flight reaction, given the fish's habitat (dim and turbid).