Biology subjects

Slater, G.

Publications and source records attributed to Slater, G..

6 recordsLinked to original sources

bioRxiv2025

Insights from U.S. beekeeper triage surveys following unusually high honey bee colony losses 2024-2025

In January of 2025, U.S. commercial beekeepers reported unusually high honey bee colony losses as they prepared colonies for almond pollination. Two industry groups launched nationwide surveys to document colony losses between June 2024 and March 2025 across all scales of beekeeping. This study analyzes these survey data to assess colony losses, estimate financial impacts, and identify correlations with beekeeper management practices and geographical locations. Unlike past surveys, commercial beekeepers experienced more severe losses than smaller-scale beekeepers during this period. Respondents, managing over half of U.S. colonies, most frequently cited Varroa mites as the cause for their losses. Varroa mites were followed by pesticides and pathogens in the case of commercial beekeepers and by queen failure and weather in the case of smaller-scale beekeepers. Although Varroa was the most frequently cited cause, losses did not significantly differ between users and non-users of amitraz, suggesting that rising amitraz resistance alone does not explain observed trends. Differences in protein and carbohydrate feeding frequencies also played a role in net losses. While colony loss rates and financial concern varied widely among respondents, commercial beekeepers understandably showed higher sensitivity to financial impacts, with concerns increasing linearly with loss severity. This study highlights the value of beekeeper surveys which, alongside direct analyses of bee samples and longitudinal studies, help identify effective management strategies and environmental risks. Such insights are crucial for addressing the leading causes of colony losses on a national scale, and ultimately aid in safeguarding honey bee health, pollination services, and agricultural production. HighlightsO_LIUnprecedented honey bee colony losses C_LIO_LIIndications of disease stress C_LIO_LIHigh economic pain for commercial beekeepers and growers C_LI

ecology↗

bioRxiv2022

Turbulent adaptive landscape shaped size evolution in modern ocean giants

Adaptive landscapes are central to evolutionary theory, forming a conceptual bridge between micro- and macro-evolution1-4. Evolution by natural selection across an adaptive landscape should drive lineages towards fitness peaks, shaping the distribution of phenotypic variation within and among clades over evolutionary timescales5. Constant shifts in selection pressures mean the peaks themselves also evolve through time4, thus a key challenge is to identify these ghosts of selection past. Here, we characterise the global and local adaptive landscape for total length in cetaceans (whales and dolphins) across their ~ 53 million year evolutionary history, using 345 living and fossil taxa. We analyse shifts in long-term mean size6 and directional changes in average trait values7 using cutting-edge phylogenetic comparative methods. We demonstrate that the global macroevolutionary adaptive landscape of cetacean body size is relatively flat, with very few peak shifts after cetaceans colonised the oceans. Local peaks represent trends along branches linked to specific adaptations such as deep diving. These results contrast with previous studies using only extant taxa8, highlighting the vital role of fossil data for understanding macroevolutionary dynamics. Our results indicate that adaptive peaks are constantly changing and are associated with subzones of local adaptations, resembling turbulent waters with waves and ripples, creating moving targets for species adaptation. In addition, we identify limits in our ability to detect some evolutionary patterns and processes, and suggest multiple approaches are required to characterise complex hierarchical patterns of adaptation in deep-time.

evolutionary biology↗

bioRxiv2022

Developmental rules of primate dental evolution align microevolution with macroevolution

Macroevolutionary biologists have classically rejected the notion that higher level patterns of divergence arise through microevolutionary processes acting within populations. For morphology, this consensus partly derives from the inability of quantitative genetics models to correctly predict the behavior of evolutionary processes at the scale of millions of years. Developmental studies (evo-devo) have been proposed to reconcile micro and macroevolution. However, there has been little progress in establishing a formal framework to apply evo-devo models of phenotypic diversification. Here, we reframe this issue by asking if using evo-devo models to quantify biological variation can improve the explanatory power of comparative models, thus helping us bridge the gap between micro- and macroevolution. We test this prediction by evaluating the evolution of primate lower molars in a comprehensive dataset densely sampled across living and extinct taxa. Our results suggest that biologically-informed morphospaces alongside quantitative genetics models allow a seamless transition between the micro and macro scales, while biologically uninformed spaces do not. We show that the adaptive landscape for primate teeth is corridor-like, with changes in morphology within the corridor being nearly neutral. Overall, our framework provides a basis for integrating evo-devo into the modern synthesis, allowing an operational way to evaluate the ultimate causes of macroevolution.

evolutionary biology↗

bioRxiv2022

Choice of 3D morphometric method leads to diverging interpretations of form--function relationships in the carnivoran calcaneus

AO_SCPLOWBSTRACTC_SCPLOWThree dimensional morphometric methods are a powerful tool for comparative analysis of shape. However, morphological shape is often represented using landmarks selected by the user to describe features of perceived importance, and this may lead to over confident prediction of form-function relationships in subsequent analyses. We used Generalized Procrustes Analysis (GPA) of 13 homologous 3D landmarks and spherical harmonics (SPHARM) analysis, a homology-free method that describes the entire shape of a closed surface, to quantify the shape of the calcaneus, a landmark poor structure that is important in hind-limb mechanics, for 111 carnivoran species spanning 12 of 13 terrestrial families. Both approaches document qualitatively similar patterns of shape variation, including a dominant continuum from short/stout to long/narrow calcanea. However, while phylogenetic generalized linear models indicate that locomotor mode best explains shape from the GPA, the same analyses find that shape described by SPHARM is best predicted by foot posture and body mass without a role for locomotor mode, though effect sizes for all are small. User choices regarding morphometric methods can dramatically impact macroevolutionary interpretations of shape change in a single structure, an outcome that is likely exacerbated when readily landmarkable features are few.

evolutionary biology↗

bioRxiv2020

Neuron-specific increase in lamin B1 disrupts nuclear function in Huntington's disease

Lamins are crucial proteins for nuclear functionality. Here, we provide new evidence showing an involvement of increased lamin B1 levels in the pathophysiology of Huntingtons disease (HD), a CAG repeat-associated neurodegenerative disorder. Through fluorescence-activated nuclear suspension imaging we demonstrate that nucleus from striatal medium-sized spiny and CA1 hippocampal neurons display increased lamin B1 levels, in correlation with altered nuclear morphology and nucleocytoplasmic transport disruption. Moreover, ChIP-sequencing analysis shows an alteration of lamin-associated chromatin domains in hippocampal nuclei, which could contribute to transcriptional alterations we determined by RNA sequencing. Supporting lamin B1 alterations as a causal role in mutant-huntingtin mediated neurodegeneration, pharmacological normalization of lamin B1 levels by betulinic acid administration in the R6/1 mouse model of HD restored nuclear homeostasis and prevented motor and cognitive dysfunction. Collectively, our work point out increased lamin B1 levels as a new pathogenic mechanism in HD and provides a novel target for its intervention.

neuroscience↗

bioRxiv2017

Spontaneous Phase Separation of Cocultured Cell Mixtures In vitro

During Embryogenesis, cells undergo constant organizational remodelling. Biochemical and biophysical guidance cues act in tandem to guide migration and morphogenesis into distinct cellular patterns. It has been shown that various cell types will express different configurations of cellular adhesion molecules known as cadherins and integrins. Cocultured in vitro experiments have focused on revealing the extensive genetic expression profiles that modulate embryogenesis whilst overlooking the physical cell-cell and cell-substrate interactions that influence organization. We demonstrate that NIH3T3 and MDCK cells undergo a spontaneous phase separation when cocultured in vitro and that this phenomenon occurs through purely physical binding energies. A Monte Carlo simulation model of a mixture of cells with different cell-cell and cell-substrate binding energies reveals that the spontaneous phase separation occurs due to the minimization of interfacial free energy within the system. Cell-cell and cell-substrate binding plays a critical role in cell organization and is capable of phase separating different populations of cells in vitro.

biophysics↗