Biology subjects

White, T. E.

Publications and source records attributed to White, T. E..

14 recordsLinked to original sources

bioRxiv2026

Chromatic contrasts predict human target detection in a natural search task

Natural scenes are visually complex, with dynamic variation in colour and luminance presenting challenges for detecting salient objects. However, the cues guiding human detection under such natural conditions remain largely untested. We placed custom-built coloured targets in a forest-like setting and quantified their contrasts against natural backgrounds using human visual models. Across human observers (n = 51), detection performance rose sharply with hue and saturation contrast, whereas luminance contrast--long considered a primary driver of visual search--contributed little explanatory power. Strikingly, even large changes in ambient light chromaticity barely altered detection, despite the patchy illumination of the habitat. Under these naturalistic conditions, hue and saturation contrasts were stronger predictors of detection than luminance contrast, providing a rare, field-based test of visual models widely applied across human and animal vision research.

animal behavior and cognition↗

bioRxiv2025

Increases in invertebrate abundance and shifts in assemblage composition following Rodent Eradication on Lord Howe Island

Invasive species are one of the major threatening processes impacting biodiversity on islands. In particular, introduced rodents represent one of the most serious threats to island ecosystems, affecting a wide range of native plants, vertebrates and invertebrates. While nearly ubiquitous on human-modified islands, the last four decades have seen the advent of targeted rodent eradications, which have generally resulted in positive impacts for biodiversity. Invertebrates, which are crucial to the functioning of island ecosystems, are known to be negatively impacted by rodents, but their response to rodent removal is less well understood. The largest rodent eradication on an inhabited island was undertaken in 2019 on Australias Lord Howe Island, which successfully extirpated black rats (Rattus rattus) and house mice (Mus musculus) more than a century after their introduction. To examine the impacts of rodents on invertebrates on Lord Howe Island, we collected arboreal and terrestrial species both pre- and post-eradication and identified them to Order. Total invertebrate abundance increased after the eradication of rodents, alongside substantial shifts in assemblage composition, however Ordinal diversity did not change significantly. Orders with large increases in abundance included Isopoda and Blattodea, while the abundance of Coleoptera and Polydesmida did not change. In addition, the abundance of large invertebrates, which are presumably subject to stronger rat predation, rose dramatically following rodent eradication. Our results suggest an ecological rearrangement following the relaxation of predation pressure and augment documented evidence of improved biodiversity outcomes for forest tree species, seabirds and land birds.

ecology↗

bioRxiv2025

Development of antibody-drug conjugates targeting L1CAM to treat metastatic cancer

Effective treatment for metastatic cancer has remained elusive due to the persistence of drug-resistant metastasis stem cells (MetSCs) that drive relapse. MetSCs are tumor cell subpopulations enriched for their ability to reinitiate and sustain metastatic growth, displaying phenotypic plasticity and resistance to chemotherapy. These cells express the L1 cell adhesion molecule (L1CAM), a transmembrane protein detected in numerous human solid tumor types and at multiple disseminated organ sites. As a selective surface marker of MetSCs, L1CAM is a promising candidate for molecularly targeted drugs aimed at eliminating metastases, yet strategies to date have not achieved clinical success. Here, we develop antibody-drug conjugates to deliver highly toxic PNU-159682 payloads to L1CAM-expressing cells. We report the generation of monoclonal antibodies (mAb) with high binding affinity, specificity and selectivity for the human L1CAM extracellular domain. Optimized L1CAM-targeting mAbs were conjugated to PNU-159682 to generate ADC variants with both cleavable and non-cleavable linkers, with an average drug-antibody-ratio (DAR) of four. ADCs derived from three antibodies targeting various epitopes of the L1CAM extracellular portion potently killed cells exhibiting varying levels of surface L1CAM expression. L1CAM ADCs given as monotherapy resulted in robust tumor control and extended survival in mice harboring subcutaneous L1CAM+ xenografts or L1CAM+ lung metastases from triple-negative basal breast cancer and lung adenocarcinoma. Safety analyses with mouse cross-reactive antibodies indicate a feasible therapeutic window. Our findings offer strong proof-of-concept to support the preclinical development of these novel L1CAM ADCs as therapeutic agents for advanced solid tumors.

cancer biology↗

bioRxiv2025

Flexible Self-Protection as Evidence of Pain-Like States in House Crickets

The possibility that insects experience pain is a frontier question at the intersection of behaviour, cognition, and philosophy of mind. Interest has been fuelled not only by anatomical discoveries but also by expanding behavioural and comparative evidence. Leading frameworks emphasise behavioural indicators of pain-like experience such as flexible, targeted responses to harm beyond reflexive withdrawal. Here we tested for such responses in the house cricket (Acheta domesticus), a species of evolutionary and commercial importance. Using a fully blinded, within-subjects design, we applied noxious heat, innocuous tactile contact, or no contact to a single antenna under lower- and higher-stress environmental conditions and recorded grooming behaviour. Crickets were significantly more likely to groom the noxiously stimulated antenna, and did so for longer, than under control or tactile treatments. Grooming also showed a distinct temporal profile, with elevated activity sustained across the early observation period. Environmental condition and sex had no effect, indicating that self-protective grooming was expressed consistently throughout. These findings provide robust evidence of flexible, site-directed self-protection in Orthoptera, addressing a key gap in evidence for pain-like states outside vertebrates. This strengthens the case for consideration of insect welfare and bears on how felt experience is distributed across the animal kingdom.

animal behavior and cognition↗

bioRxiv2025

Courtship choreography is stabilised among genetically isolated populations

Sexual selection has sculpted diverse and intricate courtship displays throughout the animal kingdom, where failure to achieve the choreographic standards of a potential partner can be highly costly for reproductive success. Yet this raises a paradox: if there is such strong selection for optimal display choreography within species, how do courtship displays diversify so extensively between species? To address this, we measure how the choreography of courtship changes among allopatric populations of the dancing dune fly - Apotropina ornatipennis Malloch (Diptera: Chloropidae) - a species in which males and females spend their days cavorting on Australias hot sandy beaches. Merging population genetics with detailed quantification of the courtship display we explore which elements of the display are the first to diverge between isolated populations, whether new behaviours arise rapidly, and whether sequence rearrangements occur in the modular structure of the display. We find that these tiny flies express courtship repertoires approaching the levels of visual complexity seen in birds of paradise. Yet despite clear genetic and geographic isolation, the complex choreography of courtship displays is stable among populations. In contrast to the notion that courtship behaviour should be highly evolvable and rapidly diverge among allopatric populations, our findings suggests that the complex choreography of courtship can instead act as a stabilising feature that limits divergence over short evolutionary timescales.

evolutionary biology↗

bioRxiv2024

Analysis-ready VCF at Biobank scale using Zarr

BackgroundVariant Call Format (VCF) is the standard file format for interchanging genetic variation data and associated quality control metrics. The usual row-wise encoding of the VCF data model (either as text or packed binary) emphasises efficient retrieval of all data for a given variant, but accessing data on a field or sample basis is inefficient. Biobank scale datasets currently available consist of hundreds of thousands of whole genomes and hundreds of terabytes of compressed VCF. Row-wise data storage is fundamentally unsuitable and a more scalable approach is needed. ResultsZarr is a format for storing multi-dimensional data that is widely used across the sciences, and is ideally suited to massively parallel processing. We present the VCF Zarr specification, an encoding of the VCF data model using Zarr, along with fundamental software infrastructure for efficient and reliable conversion at scale. We show how this format is far more efficient than standard VCF based approaches, and competitive with specialised methods for storing genotype data in terms of compression ratios and single-threaded calculation performance. We present case studies on subsets of three large human datasets (Genomics England: n=78,195; Our Future Health: n=651,050; All of Us: n=245,394) along with whole genome datasets for Norway Spruce (n=1,063) and SARS-CoV-2 (n=4,484,157). We demonstrate the potential for VCF Zarr to enable a new generation of high-performance and cost-effective applications via illustrative examples using cloud computing and GPUs. ConclusionsLarge row-encoded VCF files are a major bottleneck for current research, and storing and processing these files incurs a substantial cost. The VCF Zarr specification, building on widely-used, open-source technologies has the potential to greatly reduce these costs, and may enable a diverse ecosystem of next-generation tools for analysing genetic variation data directly from cloud-based object stores, while maintaining compatibility with existing file-oriented workflows. Key PointsO_LIVCF is widely supported, and the underlying data model entrenched in bioinformatics pipelines. C_LIO_LIThe standard row-wise encoding as text (or binary) is inherently inefficient for large-scale data processing. C_LIO_LIThe Zarr format provides an efficient solution, by encoding fields in the VCF separately in chunk-compressed binary format. C_LI

bioinformatics↗

bioRxiv2023

Automated workflows using Quantitative Colour Pattern Analysis (QCPA): A guide to batch processing and downstream data analysis

Animal and plant colouration presents a striking dimension of phenotypic variation, the study of which has driven general advances in ecology, evolution, and animal behaviour. Quantitative Colour Pattern Analysis (QCPA) is a dynamic framework for analysing colour patterns through the eyes of non-human observers. However, its extensive array of user-defined image processing and analysis tools means image analysis is often time-consuming. This hinders the full use of analytical power provided by QCPA and its application to large datasets. Here, we offer a robust and comprehensive batch script, allowing users to automate many QCPA workflows. We further provide a set of useful R scripts for downstream data extraction and analysis. These scripts will empower users to exploit the full analytical power of QCPA and facilitate the development of customised semi-automated workflows. Such quantitatively scaled workflows are crucial for exploring colour pattern space and developing ever-richer frameworks for analysing organismal colouration accounting for the visual perception in animals other than humans. These advances will, in turn, facilitate testing hypotheses on the function and evolution of vision and signals at quantitative and qualitative scales, which are otherwise computationally unfeasible.

animal behavior and cognition↗

bioRxiv2022

The effect of elevated aestivation temperatures on the behaviour of Bogong Moths (Agrotis infusa)

Bogong moths are an iconic Australian insect that migrates annually in spring from low elevation locations in southern and eastern Australia to the Australian Alps where they aestivate during summer. As summer ends they make their return journey to the breeding grounds where they mate, lay eggs and die. Given the moths extreme behaviour in seeking out cool alpine habitat and with the knowledge that average temperatures at their aestivation sites are rising because of climate change, we assessed whether increased temperatures affect Bogong moth activity during aestivation. Our first hypothesis was that moth activity would be affected by temperature, and we found that moths were more active at higher temperatures, especially during the day, with near-constant activity at 15 {degrees}C at all times of day. Our second hypothesis was that moth mass would be different after aestivating at different temperatures for a week due to dehydration or consumption of body energy reserves. We found that moth wet mass loss increased with increasing temperature, but found no difference in dry mass among temperature treatments. Overall, our results suggest that Bogong moth activity will increase with increasing temperatures at their aestivation sites. The impact of warming on the success of individuals to complete their aestivation and journey back to their lowlands to breed should be investigated as a matter of priority to better understand the impact of changes in aestivation behaviour on population dynamics.

physiology↗

bioRxiv2021

Heightened condition dependent expression of structural colouration in the faces, but not wings, of male and female flies

Structurally coloured sexual signals are a conspicuous and widespread class of ornament used in mate choice, though the extent to which they encode information on the quality of their bearers is not fully resolved. Theory predicts that signalling traits under strong sexual selection as honest indicators should evolve to be more developmentally integrated and exaggerated than nonsexual traits, thereby leading to heightened condition dependence. Here we test this prediction through examination of the sexually dimorphic faces and wings of the cursorial fly Lispe cana. Males and females possess structural UV-white and golden faces, respectively, and males present their faces and wings to females during close-range, ground-based courtship displays, thereby creating the opportunity for mutual inspection. Across a field-collected sample of individuals, we found that the appearance of the faces of both sexes scaled positively with individual condition, though along separate axes. Males in better condition expressed brighter faces as modelled according to conspecific flies, whereas condition scaled with facial saturation in females. We found no such relationships for their wing interference pattern nor abdomens, with the latter included as a nonsexual control. Our results suggest that the structurally coloured faces, but not the iridescent wings, of male and female Lispe cana are reliable guides to individual quality and support the broader potential for structural colours as honest signals. They also highlight the potential for mutual mate choice in this system, while arguing for one of several alternate signalling roles for wing interferences patterns among the myriad taxa which bear them.

evolutionary biology↗

bioRxiv2020

Flies improve the salience of iridescent sexual signals by orienting toward the sun

Sunlight is the ultimate source of most visual signals. Theory predicts strong selection for its effective use during communication, with functional links between signal designs and display behaviours a likely result. This is particularly true for iridescent structural colours, whose moment-to-moment appearance bears a heightened sensitivity to the position of signallers, receivers, and the sun. Here we experimentally tested this prediction using Lispe cana, a muscid fly in which males present their structurally coloured faces and wings to females during ground-based sexual displays. In field-based assays we found that males actively bias the orientation of their displays toward the solar azimuth under conditions of full sunlight and do so across the entire day. This bias breaks down, however, when the sun is naturally concealed by heavy cloud or experimentally obscured. Our modelling of the appearance of male signals revealed clear benefits for the salience of male ornaments, with a roughly four-fold increase in subjective luminance achievable through accurate display orientation. These findings offer fine-scale, causal evidence for the active control of sexual displays to enhance the appearance of iridescent signals. More broadly, they speak to predicted coevolution between dynamic signal designs and presentation behaviours, and support arguments for a richer appreciation of the fluidity of visual communication.

animal behavior and cognition↗

bioRxiv2020

Love at first flight: Wing interference patterns are species-specific and sexually dimorphic in blowflies (Diptera: Calliphoridae)

Wing interference patterns (WIPs) are stable structural colours displayed on insect wings which are only visible at specific viewing geometries and against certain backgrounds. These patterns are widespread among flies and wasps, and growing evidence suggests that they may function as species- and sex-specific mating cues in a range of taxa. As such, it is expected that WIPs should differ between species and show clear sexual dimorphisms. However, the true extent to which WIPs vary between species, sexes, and individuals is currently unclear, as previous studies have only taken a qualitative approach, without considering how WIPs might be perceived by the insect. Here, we perform the first quantitative analysis of inter- and intra-specific variation in WIPs across seven Australian species of the blowfly genus Chrysomya. Using multispectral digital imaging and a tentative model of blowfly colour vision, we provide quantitative evidence that WIPs are species-specific, highlight that the extent of divergence is greater in males than in females, and demonstrate sexual dimorphisms in several species. These data provide evidence that WIPs have diversified substantially in blowflies and suggests that sexual selection may have played a role in this process.

evolutionary biology↗

bioRxiv2020

Structural colours reflect individual quality: a meta-analysis

Ornamental colouration often communicates salient information to mates, and theory predicts covariance between signal expression and individual quality. This has borne out among pigment-based signals, but the potential for honesty in structural colouration is unresolved. Here I synthesised the available evidence to test this prediction via meta-analysis and found that, overall, the expression of structurally coloured sexual signals is positively associated with individual quality. The effects varied by measure of quality, however, with body condition and immune function reliably encoded across taxa, but not age nor parasite resistance. The relationship was apparent for both the colour and brightness of signals and was slightly stronger for iridescent ornaments. These results suggest diverse pathways to the encoding and exchange of information among structural colours, while highlighting outstanding questions as to the development, visual ecology, and evolution of this striking adornment.

evolutionary biology↗

bioRxiv2019

Flies exploit predictable perspectives and backgrounds to enhance iridescent signal salience and mating success

Communication requires both the encoding of information and its effective transmission, but little is known about display traits that primarily serve to enhance efficacy. Here we examined the visual courtships of Lispe cana, a cursorial fly that lives and mates in heterogeneous foreshores, and tested the prediction that males should seek to enhance signal salience and consequent fitness through the flexible choice of display locations. We show that courting males access the field of view of females by straddling them and holding their wings closed, before moving ahead to present their structurally coloured faces in ritualised dances. Males preferentially present these UV-white signals against darker backgrounds, and the magnitude of contrast predicts female attention, which in turn predict mating success. Our results demonstrate a striking interplay between the physical and attentional manipulation of receivers and reveal novel routes to the enhancement of signal efficacy in noisy environments.

animal behavior and cognition↗

bioRxiv2018

pavo 2.0: new tools for the spectral and spatial analysis of colour in R

O_LIBiological colouration presents a canvas for the study of ecological and evolutionary processes. Enduring interest in colour-based phenotypes has driven, and been driven by, improved techniques for quantifying colour patterns in ever-more relevant ways, yet the need for flexible, open frameworks for data processing and analysis persists.\nC_LIO_LIHere we introduce pavo 2, the latest iteration of the R package pavo. This release represents the extensive refinement and expansion of existing methods, as well as a suite of new tools for the cohesive analysis of the spectral and (now) spatial structure of colour patterns and perception. At its core, the package retains a broad focus on (a) the organisation and processing of spectral and spatial data, and tools for the alternating (b) visualisation, and (c) analysis of data. Significantly, pavo 2 introduces image-analysis capabilities, providing a cohesive workflow for the comprehensive analysis of colour patterns.\nC_LIO_LIWe demonstrate the utility of pavo with a brief example centred on mimicry in Heliconius butterflies. Drawing on visual modelling, adjacency, and boundary strength analyses, we show that the combined spectral (colour and luminance) and spatial (pattern element distribution and boundary salience) features of putative models and mimics are closely aligned.\nC_LIO_LIpavo 2 offers a flexible and reproducible environment for the analysis of colour, with renewed potential to assist researchers in answering fundamental questions in sensory ecology and evolution.\nC_LI

animal behavior and cognition↗