Biology subjects

Miller, C. W.

Publications and source records attributed to Miller, C. W..

4 recordsLinked to original sources

bioRxiv2025

Effect of fluid control on the affective state of laboratory macaques

Fluid control protocols are widely used in neuroscience to motivate laboratory macaques to engage with behavioural tasks. Despite strong evidence that the physiology of the animals is not compromised by such protocols, fluid control remains controversial due to its potential impact on the psychological well-being of the animals. To address this concern, we investigated the effect of fluid control on the affective state of 23 socially-housed adult macaques (10 females) engaged in neuroscience experiments. The protocol involved up to five consecutive days of fluid control per week, followed by a minimum of two days with unrestricted fluid access. The affective state of the animals was primarily assessed by quantifying the frequency of pharmacologically-validated behavioural indicators of high-arousal negative affect (self-scratching, body shaking, self-grooming). The analysis was subsequently extended to validated behavioural indicators of low-arousal negative affect (Inactive not alert) and other behaviours suspected of indicate high-arousal negative affect but lacking proper validation (pacing, yawning). In total, 700 hours of video footage spanning up to seven years of intermittent fluid control per animal were analysed. Despite this extensive dataset, the study found no significant impact of fluid control on average, or any evidence of habituation or sensitization over the years on any of the affective state indicators. Additional results indicate that these null results are not due to a lack of sensitivity, supporting the view that fluid control, as implemented in this study, does not have an adverse impact on the psychological well-being of laboratory macaques. We argue that macaque welfare will be best served by focusing future refinement on other procedures.

animal behavior and cognition↗

bioRxiv2024

Adult diet strongly affects cuticle thickness and its injury resistance in the insect Narnia femorata (Hemiptera: Coreidae)

Arthropods are the most diverse phylum on earth, accounting for up to 90% of animal species. The cuticular exoskeleton has played a vital role in their evolutionary success, but we know surprisingly little about the factors influencing its development, structure, and biomechanical properties. In this study, we examined whether and how nutrition affects the cuticle after an insect has completed its final molt into the adult stage. We found that a high-quality adult diet provided to the leaf-footed cactus bug, Narnia femorata (Hemiptera: Coreidae), over three weeks led to 4.1-times thicker cuticle with 3.7-times greater injury resistance relative to those that consumed a poor, but still ecologically relevant, diet. We further discovered that a high-quality adult diet allowed compensation for a sub-optimal juvenile diet. The cuticle of males was more injury resistant than that of females, as expected due to the aggressive male competition in this species. Altogether, our results show that, even after the final molt, nutrition can strongly influence the development and properties of the arthropod cuticle, a phenomenon that likely has drastic fitness-related consequences for locomotion, predator-prey interactions, and resource acquisition.

zoology↗

bioRxiv2023

The evolution of multi-component weapons in the superfamily of leaf-footed bugs

Sexually selected weapons, such as the antlers of deer, claws of crabs, and tusks of beaked whales, are strikingly diverse across taxa and even within groups of closely related species. Phylogenetic comparative studies have typically taken a simplified approach to investigating the evolution of weapon diversity, examining the gains and losses of entire weapons, major shifts in size or type, or changes in location. Less understood is how individual weapon components evolve and assemble into a complete weapon. We addressed this question by examining weapon evolution in the diverse, multi-component hind-leg and body weapons of leaf-footed bugs, Superfamily Coreoidea (Hemiptera: Heteroptera). Male leaf-footed bugs use their weapons to fight for access to mating territories. We used a large multilocus dataset comprised of ultraconserved element loci for 248 species and inferred evolutionary transitions among component states using ancestral state estimation. We found that weapons added components over time with some evidence of a cyclical evolutionary pattern -- gains of components followed by losses and then gains again. Further, we found that certain trait combinations evolved repeatedly across the phylogeny. This work reveals the remarkable and dynamic evolution of weapon form in the leaf-footed bugs. It also highlights that multi-component weapons may be especially useful in providing insights into the evolutionary interplay of form and function. TEASER TEXTFor centuries, humans have been fascinated by the morphological weapons animals use to engage in battle. The diversity of sexually selected weapons is surprising, with considerable variation across even closely related groups of animals. Studies are needed that take a detailed view of the components that comprise weapons and the evolutionary assembly of these components into a complete structure. Here, we reconstruct the evolution of a multi-component weapon in a superfamily of insects. Male leaf-footed bugs use spiky, enlarged hind legs to wrestle over mating territories. We measured 15 putative weapon components across 248 species, using phylogenetic comparative analyses. We found that the number of weapon components generally increased over time, with many gains and losses of components along the way. We found that certain components were more likely to evolve with others, suggesting that specific trait combinations might be especially functional in battle. This work highlights that evolutionary studies of complex, multi-component weapons may be useful for reconstructing the evolutionary assembly of weapons and the interplay of form and function.

evolutionary biology↗

bioRxiv2020

Phylogenomics of the leaf-footed bug subfamily Coreinae (Hemiptera: Coreidae): applicability of ultraconserved elements at shallower depths

Baits targeting invertebrate ultraconserved elements (UCEs) are becoming more common for phylogenetic studies. Recent studies have shown that invertebrate UCEs typically encode proteins -- and thus, are functionally different from more conserved vertebrate UCEs --can resolve deep divergences (e.g., superorder to family ranks). However, the ability of the invertebrate UCE baits to robustly resolve relationships at shallower phylogenetic scales (i.e., tribes and congeners) has been generally limited to Coleoptera and Hymenoptera. Here, we assessed the ability of a recently designed Hemiptera UCE bait set to reconstruct more recent phylogenetic relationships in the largest leaf-footed bug subfamily, the Coreinae (Hemiptera: Coreidae), using a taxon-rich sample representing 21 of the 32 coreine tribes. Many well-supported, novel relationships were congruent in maximum likelihood and summary coalescent analyses. We also found evidence for the para- and polyphyly of several tribes and genera of Coreinae, as well as the subfamilies Coreinae and Meropachyinae. Our study, along with other recent UCE studies, provides evidence that UCEs can produce robust and novel phylogenetic hypotheses at various scales in invertebrates. Additionally, we used different DNA extraction and target enrichment protocols and recovered more UCE data using a touch-down hybridization approach.

evolutionary biology↗