Multiple differences in calling songs and other traits between solitary and gregarious Mormon crickets from allopatric mtDNA clades

The Linnaean Society, The British Ecological Society, The Russell Trust (St. Andrews), The Orthopterists' Society and an NSERC (Canada) grant to DTG. Gordon S. Brown provided assistance with digital imaging and morphological measurements.Background: In acoustic species, traits such as male calling song are likely to diverge quickly between allopatric populations due to sexual selection, and divergence in parameters such as carrier frequency, chirp structure, and other important song characters can influence sexual isolation. Here we make use of two forms of Mormon crickets to examine differences in a broad suite of traits that have the potential to influence speciation via sexual isolation. Mormon crickets in "gregarious" populations aggregate into dense migratory bands, and females are the sexually competitive Fsex ( sex- role reversal). There is also a non-outbreak "solitary" form. These two forms are largely but not perfectly correlated with a significant mtDNA subdivision within the species that is thought to have arisen in allopatry. Combined information about multiple, independently evolving traits, such as morphology and structural and behavioural differences in calling song, provides greater resolution of the overall differences between these allopatric populations, and allows us to assess their stage of divergence. We test two predictions, first that the forms differ in song and second that gregarious males are more reluctant to sing than solitary males due to sex role reversal. We also tested for a difference in the relationship between the size of the forewing resonator, the mirror, and carrier frequency, as most models of sound production in crickets indicate that mirror size should predict carrier frequency. Results: Multivariate analyses showed that solitary and gregarious individuals from different populations representing the two mtDNA clades had almost non-overlapping distributions based on multiple song and morphological measurements. Carrier frequency differed between the two, and gregarious males were more reluctant to sing overall. Mirror size predicted carrier frequency; however, the relationship between mirror size and surface area varied between solitary and gregarious forms, suggesting that factors above and beyond mirror size contribute to carrier frequency. Conclusion: The two clades of Mormon crickets differ in a broad suite of independent traits that probably justify subspecies status ( the two can successfully mate so may not be reproductively isolated). However, our results emphasize the importance of carefully distinguishing the ultimate causation of differences between traits used to delineate species or subspecies boundaries.Publisher PDFPeer reviewe

PREFERENCE OF CONSUMERS TOWARD NON-DISTORTED GRAPHICS ON FULL-BODY SHRINK SLEEVE LABELS

Past research has indicated that shrink sleeves can lead to higher product trial rates, better long-term sales, and greater likelihood of brand loyalty. A pilot study and a primary experiment were conducted to investigate the significance of distortion and the ability of the Human Visual System (HVS) to recognize it in packaging design. Distortion works primarily in shrink film on which an image is printed, so these studies dealt only with reductive distortion. The pilot study aimed to identify the absolute threshold, or Just-Noticeable-Difference (JND) for a change from no stimulus, for simple polygons. The primary experiment focused on graphic distortion in full body shrink sleeves (FBSS). Treatments presented each of the stimulus levels, along with a control for comparison, using a 2-AFC (Alternative Forced-Choice) Method. This study used a mixed 2 (labels) x 3 (bottles) x 5 (distortion increments) model, effectively 30 treatments in a Randomized Complete Block Design (RCBD). Label was a between-subject variable while Bottle Shape and Distortion Percentage were within-subject variables. Data indicated that distortion has a significant effect at 100%, but that there is not a threshold at which consumers are guaranteed to perceive graphic distortion on FBSS. Men detected distortion better than women. Participants who said distortion would prevent a purchase decision had the same tolerance as those who reported that it would not. Bottle shape may only impact consumer acceptance of distortion with some percentages of distortion. Familiarity with a brand name label may increase consumer tolerance and acceptance of distortion, and may do so more on some bottle shapes

Fritz Lang\u27s Critique of Capitalism through Body Language in Metropolis

This honors thesis argues that Fritz Lang’s 1927 silent film Metropolis contains nonverbal narrative elements (including body language, architectural proxemics, and phallic imagery) that align the film with Marxist class structures. The film provides a moral epigram, “the mediator between head and hands must be the heart,” which this paper aims to define through a Marxist lens. This thesis narrates Metropolis’ verbal and nonverbal narratives through observing intertitles in the film alongside the elements that perplex the viewer and overload the senses. The aim of this paper is to notice where the head, hands, and heart make various unexpected appearances throughout the film – in Metropolis, the conceptual head and the productive hands are aligned to specific socioeconomic statuses. The heart is what must aid dysfunction between the two

The Effects of Operator Trust, Complacency Potential, and Task Complexity on Monitoring a Highly Reliable Automated System

Technological advances have allowed for widespread implementation of automation in complex systems. However, the increase in quantity and complexity of advanced automated systems has raised a number of potential concerns including degraded monitoring skills. The present investigation consisted of two studies that assessed the impact of system reliability, complacency potential, monitoring complexity, operator trust, and system experience on monitoring performance. In both studies, participants monitored a simulated aviation display for failures while operating a manually controlled flight task. In addition, the second experiment assessed the ability of operators to detect a single automation failure over three experimental sessions. Results indicated that realistic levels of system reliability severely impaired an operator\u27s ability to monitor effectively. In addition, as system experience increased, operator performance for monitoring highly reliable systems continued to decline. Further, operators who reported higher levels of trust, confidence, and more frequent usage of automation demonstrated poorer overall monitoring. The complexity of the monitoring task was also shown to be one of the most important factors influencing operator monitoring performance with poorer performance on more cognitively demanding tasks that continued to degrade as system experience increased. Results from both studies indicated that operator trust increased as a function of increasing system reliability and that as trust increased, monitoring performance decreased. These results suggest that for highly reliable systems, increasing task complexity and extensive experience may severely impair an operator\u27s ability to monitor for unanticipated system states

Social runaway : fisherian elaboration (or reduction) of socially selected traits via indirect genetic effects

NWB was funded by fellowships from the UK Natural Environment Research Council [NE/G014906/1 and NE/L011255/1].Our understanding of the evolutionary stability of socially‐selected traits is dominated by sexual selection models originating with R. A. Fisher, in which genetic covariance arising through assortative mating can trigger exponential, runaway trait evolution. To examine whether non‐reproductive, socially‐selected traits experience similar dynamics—social runaway—when assortative mating does not automatically generate a covariance, we modelled the evolution of socially‐selected badge and donation phenotypes incorporating indirect genetic effects (IGEs) arising from the social environment. We establish a social runaway criterion based on the interaction coefficient, ψ, which describes social effects on badge and donation traits. Our models make several predictions. (1) IGEs can drive the original evolution of altruistic interactions that depend on receiver badges. (2) Donation traits are more likely to be susceptible to IGEs than badge traits. (3) Runaway dynamics in non‐sexual, social contexts can occur in the absence of a genetic covariance. (4) Traits elaborated by social runaway are more likely to involve reciprocal, but non‐symmetrical, social plasticity. Models incorporating plasticity to the social environment via IGEs illustrate conditions favouring social runaway, describe a mechanism underlying the origins of costly traits such as altruism, and support a fundamental role for phenotypic plasticity in rapid social evolution.PostprintPeer reviewe

Within-generation and transgenerational social plasticity interact during rapid adaptive evolution

Funding: We are grateful for support from the Natural Environment Research Council to NWB (NE/L011255/1 and NE/T000619/1).The effects of within-generation plasticity vs. transgenerational plasticity on trait expression are poorly understood, but important for evaluating plasticity's evolutionary consequences. We tested how genetics, within-generation plasticity, and transgenerational plasticity jointly shape traits influencing rapid evolution in the field cricket Teleogryllus oceanicus. In Hawaiian populations attacked by acoustically orienting parasitoid flies, a protective, X-linked variant ("flatwing") eliminates male acoustic sexual signals. Silent males rapidly spread to fixation, dramatically changing the acoustic environment. First, we found evidence supporting flatwing-associated pleiotropy in juveniles: pure-breeding flatwing males and females exhibit greater locomotion than those with normal-wing genotypes. Second, within-generation plasticity caused homozygous-flatwing females developing in silence, which mimics all-flatwing populations, to attain lower adult body condition and reproductive investment than those experimentally exposed to song. Third, maternal song exposure caused transgenerational plasticity in offspring, affecting adult, but not juvenile, size, condition, and reproductive investment. This contrasted with behavioral traits, which were only influenced by within-generation plasticity. Fourth, we matched and mismatched maternal and offspring social environments and found that transgenerational plasticity sometimes interacted with within-generation plasticity and sometimes opposed it. Our findings stress the importance of evaluating plasticity of different traits and stages across generations when evaluating its fitness consequences and role in adaptation.Publisher PDFPeer reviewe

Intrasexual aggression reduces mating success in field crickets

This work was supported by the UK Natural Environment Research Council (NE/L011255/1 and NE/T000619/1).Aggressive behaviour is thought to have significant consequences for fitness, sexual selection and the evolution of social interactions, but studies measuring its expression across successive encounters?both intra- and intersexual?are limited. We used the field cricket Teleogryllus oceanicus to evaluate factors affecting repeatability of male aggression and its association with mating success. We quantified focal male aggression expressed towards partners and received from partners in three successive, paired trials, each involving a different male partner. We then measured a proxy of focal male fitness in mating trials with females. The likelihood and extent of aggressive behaviour varied across trials, but repeatability was negligible, and we found no evidence that patterns of focal aggression resulted from interacting partner identity or prior experience. Males who consistently experienced aggression in previous trials showed decreased male mating ?efficiency??determined by the number of females a male encountered before successfully mating, but the effect was weak and we found no other evidence that intrasexual aggression was associated with later mating success. During mating trials, however, we observed unexpected male aggression towards females, and this was associated with markedly decreased male mating efficiency and success. Our findings suggest that nonadaptive aggressive spillover in intersexual mating contexts could be an important but underappreciated factor influencing the evolution of intrasexual aggression.Publisher PDFPeer reviewe

Behavioural plasticity compensates for adaptive loss of cricket song

Funding: Funding was provided by UK Natural Environment Research Council grants to N.W.B. (NE/L011255/1, NE/T000619/1) and a University of St Andrews School of Biology PhD studentship to W.T.S.Behavioural flexibility might help animals cope with costs of genetic variants under selection, promoting genetic adaptation. However, it has proven challenging to experimentally link behavioural flexibility to the predicted compensation of population-level fitness. We tested this prediction using the field cricket Teleogryllus oceanicus. In Hawaiian populations, a mutation silences males and protects against eavesdropping parasitoids. To examine how the loss of this critical acoustic communication signal impacts offspring production and mate location, we developed a high- resolution, individual-based tracking system for low-light, naturalistic conditions. Offspring production did not differ significantly in replicate silent versus singing populations, and fitness compensation in silent conditions was associated with significantly increased locomotion in both sexes. Our results provide evidence that flexible behaviour can promote genetic adaptation via compensation in reproductive output and suggest that rapid evolution of animal communication systems may be less constrained than previously appreciated.Peer reviewe

Ancestral sex-role plasticity facilitates the evolution of same-sex sexual behavior

This study was supported by JSPS Research Fellowships for Young Scientists CPD Grant 20J00660 (to N.M.), Grant-in-Aid for Early-Career Scientists 21K15168 (to N.M.), and Okanawa Institute of Science and Technology core funding. N.W.B. gratefully acknowledges funding from the UK Natural Environment Research Council (NE/T000619/1).Recent attempts to explain the evolutionary prevalence of same-sex sexual behavior (SSB) have focused on the role of indiscriminate mating. However, in many cases, SSB may be more complex than simple mistaken identity, instead involving mutual interactions and successful pairing between partners who can detect each other?s sex. Behavioral plasticity is essential for the expression of SSB in such circumstances. To test behavioral plasticity?s role in the evolution of SSB, we used termites to study how females and males modify their behavior in same-sex versus heterosexual pairs. Male termites follow females in paired ?tandems? before mating, and movement patterns are sexually dimorphic. Previous studies observed that adaptive same-sex tandems also occur in both sexes. Here we found that stable same-sex tandems are achieved by behavioral plasticity when one partner adopts the other sex?s movements, resulting in behavioral dimorphism. Simulations based on empirically obtained parameters indicated that this socially cued plasticity contributes to pair maintenance, because dimorphic movements improve reunion success upon accidental separation. A systematic literature survey and phylogenetic comparative analysis suggest that the ancestors of modern termites lack consistent sex roles during pairing, indicating that plasticity is inherited from the ancestor. Socioenvironmental induction of ancestral behavioral potential may be of widespread importance to the expression of SSB. Our findings challenge recent arguments for a prominent role of indiscriminate mating behavior in the evolutionary origin and maintenance of SSB across diverse taxa.Publisher PDFPeer reviewe

Multiple differences in calling songs and other traits between solitary and gregarious Mormon crickets from allopatric mtDNA clades

BACKGROUND: In acoustic species, traits such as male calling song are likely to diverge quickly between allopatric populations due to sexual selection, and divergence in parameters such as carrier frequency, chirp structure, and other important song characters can influence sexual isolation. Here we make use of two forms of Mormon crickets to examine differences in a broad suite of traits that have the potential to influence speciation via sexual isolation. Mormon crickets in "gregarious" populations aggregate into dense migratory bands, and females are the sexually competitive sex (sex-role reversal). There is also a non-outbreak "solitary" form. These two forms are largely but not perfectly correlated with a significant mtDNA subdivision within the species that is thought to have arisen in allopatry. Combined information about multiple, independently evolving traits, such as morphology and structural and behavioural differences in calling song, provides greater resolution of the overall differences between these allopatric populations, and allows us to assess their stage of divergence. We test two predictions, first that the forms differ in song and second that gregarious males are more reluctant to sing than solitary males due to sex role reversal. We also tested for a difference in the relationship between the size of the forewing resonator, the mirror, and carrier frequency, as most models of sound production in crickets indicate that mirror size should predict carrier frequency. RESULTS: Multivariate analyses showed that solitary and gregarious individuals from different populations representing the two mtDNA clades had almost non-overlapping distributions based on multiple song and morphological measurements. Carrier frequency differed between the two, and gregarious males were more reluctant to sing overall. Mirror size predicted carrier frequency; however, the relationship between mirror size and surface area varied between solitary and gregarious forms, suggesting that factors above and beyond mirror size contribute to carrier frequency. CONCLUSION: The two clades of Mormon crickets differ in a broad suite of independent traits that probably justify subspecies status (the two can successfully mate so may not be reproductively isolated). However, our results emphasize the importance of carefully distinguishing the ultimate causation of differences between traits used to delineate species or subspecies boundaries