Do Sex Ratio Distorting Microbes Inhibit the Evolution of Pesticide Resistance? An Experimental Test.

We are still largely reliant on pesticides for the suppression of arthropod pests which threaten human health and food production, but the recent rise of evolved resistance among important pest species has reduced pesticide efficacy. Despite this, our understanding of strategies that effectively limit the evolution of resistance remains weak. Male-killing sex ratio distorting microbes (SRDMs), such as and , are common among arthropod species.

Alternative reproductive tactics and evolutionary rescue.

Almost all life on earth is facing environmental change, and understanding how populations will respond to these changes is of urgent importance. One factor that is known to affect the speed by which a population can evolve when faced with changes in the environment is strong sexual selection. This increases the adaptive capacity of a population by increasing reproductive skew toward well-adapted (usually) males who will, on average, be best able to compete for matings.

Sex ratio distorting microbes exacerbate arthropod extinction risk in variable environments.

Maternally-inherited sex ratio distorting microbes (SRDMs) are common among arthropod species. Typically, these microbes cause female-biased sex ratios in host broods, either by; killing male offspring, feminising male offspring, or inducing parthenogenesis. As a result, infected populations can experience drastic ecological and evolutionary change.

Regulation of photosynthetic electron flow on dark to light transition by ferredoxin:NADP(H) oxidoreductase interactions.

During photosynthesis, electron transport is necessary for carbon assimilation and must be regulated to minimize free radical damage. There is a longstanding controversy over the role of a critical enzyme in this process (ferredoxin:NADP(H) oxidoreductase, or FNR), and in particular its location within chloroplasts. Here we use immunogold labelling to prove that FNR previously assigned as soluble is in fact membrane associated.

Metacommunity-scale biodiversity regulation and the self-organised emergence of macroecological patterns.

There exist a number of key macroecological patterns whose ubiquity suggests that the spatio-temporal structure of ecological communities is governed by some universal mechanisms. The nature of these mechanisms, however, remains poorly understood. Here, we probe spatio-temporal patterns in species richness and community composition using a simple metacommunity assembly model.

Warming at the population level: Effects on age structure, density, and generation cycles.

The impact of climate change on strongly age-structured populations is poorly understood, despite the central role of temperature in determining developmental rates in ectotherms. Here we examine the effect of warming and its interactions with resource availability on the population dynamics of the pyralid moth populations of which normally show generation cycles, a consequence of strong and asymmetric age-related competition. Warming by 3°C above the standard culture temperature led to substantial changes in population density, age structure, and population dynamics.

Sperm morph and remating frequency in the Indian meal moth, .

All Lepidoptera produce two sperm types: normal, nucleated 'eupyrene' sperm and anucleate 'apyrene' sperm. One hypothesis for the evolution of apyrene sperm suggests that they act to reduce female remating rate. Apyrene sperm require less resources to produce than do eupyrene sperm, and could delay remating by females by acting as a 'cheap filler', packing the spermatheca and thereby reducing receptivity.

The effect of sexual selection on adaptation and extinction under increasing temperatures.

Strong sexual selection has been reported to both enhance and hinder the adaptive capacity and persistence of populations when exposed to novel environments. Consequently, how sexual selection influences population adaption and persistence under stress remains widely debated. Here, we present two empirical investigations of the fitness consequences of sexual selection on populations of the Indian meal moth, exposed to stable or gradually increasing temperatures.

Patterns of divergence in the morphology of ceratopsian dinosaurs: sympatry is not a driver of ornament evolution.

Establishing the origin and function of unusual traits in fossil taxa provides a crucial tool in understanding macroevolutionary patterns over long periods of time. Ceratopsian dinosaurs are known for their exaggerated and often elaborate horns and frills, which vary considerably between species. Many explanations have been proposed for the origin and evolution of these 'ornamental' traits, from predator defence to socio-sexual dominance signalling and, more recently, species recognition.

Diverse and complex male polymorphisms in Odontolabis stag beetles (Coleoptera: Lucanidae).

When male animals engage in intrasexual contests then any alternative tactics they use can be associated with dimorphisms in the expression of weapons. Some species have recently been found to exhibit trimorphism in their weaponry, suggesting that the processes leading to their evolution and maintenance of these polymorphisms can be more complex than previously thought. Here, we describe the extraordinary diversity of polymorphism within the genus Odontolabis: there are dimorphic species (O.

Responses to a warming world: Integrating life history, immune investment, and pathogen resistance in a model insect species.

Environmental temperature has important effects on the physiology and life history of ectothermic animals, including investment in the immune system and the infectious capacity of pathogens. Numerous studies have examined individual components of these complex systems, but little is known about how they integrate when animals are exposed to different temperatures. Here, we use the Indian meal moth () to understand how immune investment and disease resistance react and potentially trade-off with other life-history traits.

Selective harvest focused on sexual signal traits can lead to extinction under directional environmental change.

Humans commonly harvest animals based on their expression of secondary sexual traits such as horns or antlers. This selective harvest is thought to have little effect on harvested populations because offtake rates are low and usually only the males are targeted. These arguments do not, however, take the relationship between secondary sexual trait expression and animal condition into account: there is increasing evidence that in many cases the degree of expression of such traits is correlated with an animal's overall well-being, which is partly determined by their genetic match to the environment.

Within- and Trans-Generational Effects of Variation in Dietary Macronutrient Content on Life-History Traits in the Moth Plodia interpunctella.

It is increasingly clear that parental environment can play an important role in determining offspring phenotype. These "transgenerational effects" have been linked to many different components of the environment, including toxin exposure, infection with pathogens and parasites, temperature and food quality. In this study, we focus on the latter, asking how variation in the quantity and quality of nutrition affects future generations.

Sexual selection can both increase and decrease extinction probability: reconciling demographic and evolutionary factors.

Previous theoretical models of the effect of sexual selection on average individual fitness in a population have mostly predicted that sexually selected populations should adapt faster and clear deleterious mutations more quickly than populations where sexual selection is not operating. While some laboratory studies have supported these predictions, others have not and studies of field systems have tended to find negative effects of sexual selection, or no effect. The negative effects of sexual selection found in field and other studies are usually ascribed to the costs associated with strong sexual selection acting on the population.

Genome size and ploidy influence angiosperm species' biomass under nitrogen and phosphorus limitation.

Angiosperm genome sizes (GS) range c. 2400-fold, and as nucleic acids are amongst the most phosphorus- (P) and nitrogen (N)-demanding cellular biomolecules, we test the hypothesis that a key influence on plant biomass and species composition is the interaction between N and P availability and plant GS. We analysed the impact of different nutrient regimes on above-ground biomass of angiosperm species with different GS, ploidy level and Grime's C-S-R (competitive, stress-tolerant, ruderal) plant strategies growing at the Park Grass Experiment (Rothamsted, UK), established in 1856.

Building a Beetle: How Larval Environment Leads to Adult Performance in a Horned Beetle.

The link between the expression of the signals used by male animals in contests with the traits which determine success in those contests is poorly understood. This is particularly true in holometabolous insects such as horned beetles where signal expression is determined during metamorphosis and is fixed during adulthood, whereas performance is influenced by post-eclosion feeding. We used path analysis to investigate the relationships between larval and adult nutrition, horn and body size and fitness-related traits such as strength and testes mass in the horned beetle Euoniticellus intermedius.

Disease epidemiology in arthropods is altered by the presence of nonprotective symbionts.

Inherited microbial symbionts can modulate host susceptibility to natural enemy attack. A wider range of symbionts influence host population demography without altering individual susceptibility, and it has been suggested that these may modify host disease risk through altering the rate of exposure to natural enemies. We present the first test of this thesis, specifically testing whether male-killing symbionts alter the epidemiology of a sexually transmitted infection (STI) carried by its host.

Control and target gene selection for studies on UV-induced genotoxicity in whales.

Background: Despite international success in reducing ozone-depleting emissions, ultraviolet radiation (UV) is not expected to decrease for several decades. Thus, it is pressing to implement tools that allow investigating the capacity of wildlife to respond to excessive UV, particularly species like cetaceans that lack anatomical or physiological protection. One approach is to examine epidermal expression of key genes involved in genotoxic stress response pathways.

Effects of oil-palm plantations on diversity of tropical anurans.

Agriculturally altered vegetation, especially oil-palm plantations, is rapidly increasing in Southeast Asia. Low species diversity is associated with this commodity, but data on anuran diversity in oil-palm plantations are lacking. We investigated how anuran biological diversity differs between forest and oil-palm plantation, and whether observed differences in biological diversity of these areas is linked to specific environmental factors.