Male crickets in poor condition engage in less same-sex sexual behavior.

Same-sex sexual behavior (SSB) is widespread among animals and is often treated as an evolutionary anomaly or mistake. An alternative view is that SSB occurs because individuals have broader or more permissive "mating filters." A broader filter means directing courtship toward anything that resembles a potential mate, while a narrower filter means having stricter criteria about when to court.

Meta-analytical evidence that males prefer virgin females.

Males are often predicted to prefer virgin over non-virgin females because of the reduced risk of sperm competition. Does this prediction hold across studies? Our systematic meta-analysis of 138 studies, mainly conducted in invertebrates, confirms that males generally prefer virgin females. However, males preferred virgin females even in species with last male sperm precedence, suggesting that sperm competition alone does not drive male preferences.

Rethinking same-sex sexual behaviour: male field crickets have broad mating filters.

Same-sex sexual behaviour (SSB) occurs in many animals and is often treated as an anomaly requiring special explanation. One common explanation for SSB is mistaken identity. However, animals make similar 'mistakes' in other contexts-such as attempting to mate with immature individuals or inanimate objects.

Sex-specific associations between life-history traits and a novel reproductive polymorphism in the Pacific field cricket.

Associations between heritable polymorphisms and life-history traits, such as development time or reproductive investment, may play an underappreciated role in maintaining polymorphic systems. This is because selection acting on a particular morph could be bolstered or disrupted by correlated changes in life history or vice versa. In a Hawaiian population of the Pacific field cricket (Teleogryllus oceanicus), a novel mutation (flatwing) on the X-chromosome is responsible for a heritable polymorphism in male wing structure.

Increased allocation to reproduction reduces future competitive ability in a burying beetle.

The existence of a trade-off between current and future reproduction is a fundamental prediction of life history theory. Support for this prediction comes from brood size manipulations, showing that caring for enlarged broods often reduces the parent's future survival or fecundity. However, in many species, individuals must invest in competing for the resources required for future reproduction.

Females adjust maternal hormone concentration in eggs according to male condition in a burying beetle.

In birds and other vertebrates, there is good evidence that females adjust the allocation of hormones in their eggs in response to prenatal environmental conditions, such as food availability or male phenotype, with profound consequences for life history traits of offspring. In insects, there is also evidence that females deposit juvenile hormones (JH) and ecdysteroids (ESH) in their eggs, hormones that play a key role in regulating offspring growth and metamorphosis. However, it is unclear whether females adjust their hormonal deposition in eggs in response to prenatal environmental conditions.

Interplay between age-based competitive asymmetries within the brood and direct competition between inbred and outbred offspring in a burying beetle.

Theory suggests that intraspecific competition associated with direct competition between inbred and outbred individuals should be an important determinant of the severity of inbreeding depression. The reason is that, if outbred individuals are stronger competitors than inbred ones, direct competition should have a disproportionate effect on the fitness of inbred individuals. However, an individual's competitive ability is not only determined by its inbreeding status but also by competitive asymmetries that are independent of an individual's inbreeding status.

Effects of variation in resource acquisition during different stages of the life cycle on life-history traits and trade-offs in a burying beetle.

Individual variation in resource acquisition should have consequences for life-history traits and trade-offs between them because such variation determines how many resources can be allocated to different life-history functions, such as growth, survival and reproduction. Since resource acquisition can vary across an individual's life cycle, the consequences for life-history traits and trade-offs may depend on when during the life cycle resources are limited. We tested for differential and/or interactive effects of variation in resource acquisition in the burying beetle Nicrophorus vespilloides.

No evidence of sibling cooperation in the absence of parental care in Nicrophorus vespilloides.

Interactions among siblings fall on a continuum with competition and cooperation at opposite ends of the spectrum. Prior work on the burying beetle Nicrophorus vespilloides suggests that parental care shifts the balance between competition and cooperation by masking a density-dependent shift from cooperation to competition. However, these results should be interpreted with caution because they were based on correlational evidence for an association between larval density at dispersal and mean larval mass at dispersal.

Inbred burying beetles suffer fitness costs from making poor decisions.

There is growing interest in how environmental conditions, such as resource availability, can modify the severity of inbreeding depression. However, little is known about whether inbreeding depression is also associated with differences in individual decision-making. For example, decisions about how many offspring to produce are often based upon the prevailing environmental conditions, such as resource availability, and getting these decisions wrong may have important fitness consequences for both parents and offspring.

Effects of Offspring and Parental Inbreeding on Parent-Offspring Communication.

There is mounting evidence that inbreeding can have complex effects on social interactions among inbred and outbred individuals. Here, we investigate effects of offspring and maternal inbreeding on parent-offspring communication in the burying beetle Nicrophorus vespilloides. We find effects of the interaction between offspring and maternal inbreeding on maternal behavior.

Intraspecific Competition and Inbreeding Depression: Increased Competitive Effort by Inbred Males Is Costly to Outbred Opponents.

A recent theoretical model suggests that intraspecific competition is an important determinant of the severity of inbreeding depression. The reason for this is that intraspecific competition is density dependent, leading to a stronger negative effect on inbred individuals if they are weaker competitors than outbred ones. In support of this prediction, previous empirical work shows that inbred individuals are weaker competitors than outbred ones and that intraspecific competition often exacerbates inbreeding depression.

Waist-to-height ratio is more predictive of years of life lost than body mass index.

Objective: Our aim was to compare the effect of central obesity (measured by waist-to-height ratio, WHtR) and total obesity (measured by body mass index, BMI) on life expectancy expressed as years of life lost (YLL), using data on British adults.

Methods: A Cox proportional hazards model was applied to data from the prospective Health and Lifestyle Survey (HALS) and the cross sectional Health Survey for England (HSE). The number of years of life lost (YLL) at three ages (30, 50, 70 years) was found by comparing the life expectancies of obese lives with those of lives at optimum levels of BMI and WHtR.