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).

Summary: Kessler et al. (2012)

The evolution of social systems has been largely influenced by kin selection. Within a social group, the ability to recognize paternal kin is important for minimizing inbreeding and loss of genetic diversity. Kessler et al. (2012) investigated vocal paternal kin recognition in the grey mouse lemur (Microcebus murinus), one of the first studies to do so. They analysed ultrasonic male courtship and alarm calls, and found that advertisement calls contain patrilineal signatures, which females use to assess relatedness of males. Alarm calls did not seem to contain these signatures. Kessler et al. (2012) conclude that paternal kin recognition is not reliant on brain size or social complexity, but could be the ancestral state from which more complex, kin-based sociality has arisen.

Summary: Foster et al. (2012)

Postmenopausal life span in humans has encouraged studies investigating the evolution prolonged post-reproductive life span in other animals. Two mechanisms are proposed: 1) increased longevity - evolutionary benefits accumulate only during the reproductive phase; 2) evolved adaptation - the post-reproductive life span increases individual "genetic" survival, resulting in increased inclusive fitness. Foster et al. (2012) used a Cox proportional hazards model (6) to study the influence of a mother killer whale’s (Orcinus orca) death on offspring survival. Neither sex disperses from the maternal group, so old mothers can maximise their inclusive fitness by increasing offspring survival and reproductive success. In addition, mothers should only help sons, as mating occurs outside the matriline. Foster et al. (2012) showed that old females assist male offspring. As reproductive success increases with male age, increased survival of sons increases the inclusive fitness of mothers. Mothers can assist with foraging or will provide support during agonistic encounters. Foster et al.'s (2012) results support the premise that a long post-reproductive life span is an evolved adaptation.

Summary: Hut & Scharff (1998)

Endoscopic equipment can be used to observe the behaviour of ground-dwelling animals inside their burrows. Hut & Scharff (1998) used a 205cm manoeuvrable fibre optic industrial endoscope attached to a video system to assess tunnel-blocking behaviour in European ground squirrels Spermophilus citellus. They found that, in 82% of cases, a tunnel block was found approximately 57 cm from the tunnel entrance. They suggest that ground squirrels are actively avoiding under-ground predation by blocking the tunnels with sand, and that they do this when both entering and leaving the burrow. Hut & Scharff (1998) suggest that these squirrels likely show a high tolerance to low oxygen (hypoxia) and high carbon dioxide (hypercapnia) conditions.