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.