Biology subjects

Alton, L. A.

Publications and source records attributed to Alton, L. A..

3 recordsLinked to original sources

bioRxiv2026

Genetic Variation in Organ System Decline Across the Drosophila Genetics Reference Panel

Genetic background has a significant impact on an organism's lifespan. Underlying this metric, ageing is characterised by a sequence of physiological systems decline that leads to death. Despite this, much of the ageing research performed on model organisms in the lab uses lifespan, rather than physiological decline, as a metric to measure ageing. Here, we sought to establish if differing genotype alters age-related organ system decline by repeatedly measuring the function of five organ systems throughout the lifespan of 19 lines from the Drosophila Genetic Reference Panel. We found that the magnitude of each organ system's decline differs across genotypes, and that different organ systems decline at different rates within a genotype. We also uncovered that while declines in activity rate and reproduction were associated with length of life, overall patterns of phenotypic organ system decline differed significantly across genotypes. Overall, these data suggest that individuals with different genetic backgrounds have distinct patterns of physiological decline, implying that the mechanisms driving ageing vary between individuals. These data underscore the importance of studying organ systems decline in addition to lifespan to gain a full understanding of ageing.

genetics↗

bioRxiv2025

Local adaptation in climate tolerance at a small geographic scale contrasts with broad latitudinal patterns

While climate adaptation is typically quantified across broad gradients, the potential for adaptation to the same environmental variables at small scales is rarely tested. If local-scale environmental heterogeneity can generate patterns of adaptation similar to broad gradients, then we currently underestimate adaptive capacity to global change. We quantified population variation in climate tolerance traits and their plasticity for five populations of Drosophila melanogaster from a 3000-km latitudinal gradient, which we contrasted with eight local populations from an environmentally heterogeneous 600x300km area. Population variation in stress tolerance at the local scale was comparable to that across latitude. Consistent with local adaptation, populations from warmer and drier environments showed greater heat and desiccation tolerance, and populations from more predictable environments showed greater plasticity. Climate adaptation at smaller geographic scales can therefore be comparable to adaptation across broad geographic scales. However, patterns of adaptation often changed across geography, which makes predicting responses to global change challenging.

evolutionary biology↗

bioRxiv2022

Physiological traits and their relationships vary along an aridity gradient within and among Fijian bee species

O_LITemperature and water availability are hypothesised to be important abiotic drivers of the evolution of metabolic rates and gas exchange patterns, respectively. Specifically, the metabolic cold adaptation hypothesis (MCA) predicts that cold environments select for faster metabolic rates to counter the thermodynamics of biochemical reactions while the hygric hypothesis predicts that dry environments select for discontinuous gas exchange to reduce water loss. C_LIO_LIAlthough these two hypotheses consider different physiological traits and how they vary along different abiotic gradients, metabolic rate drives frequency of gas exchange patterns in insects meaning these two traits are inherently linked. Despite this link, the MCA and hygric hypotheses are rarely considered together and the extent to which metabolic rates and frequency of gas exchange vary and co-vary across climatic gradients remains unclear. C_LIO_LIWe tested the MCA and hygric hypotheses within a species of endemic Fijian bee, Homalictus fijiensis, across an altitudinal gradient of 1100 m, and among four Fijian bee species, including H. fijiensis, that inhabit different altitudinal bands. In Fiji, environmental temperature is [~]5{degrees}C lower in the central highlands than in the coastal lowlands with the highlands receiving [~]100 mm of additional precipitation than the lowlands each month. C_LIO_LIWe found an MCA-like pattern within H. fijiensis and among Fijian bee species, where metabolic rate decreased with increasing temperature, but precipitation also explained variation in metabolic rate. However, we did not find support for the hygric hypothesis within H. fijiensis or among species (frequency of gas exchange was not negatively correlated with precipitation). C_LIO_LIThe relationship between metabolic rate and frequency of gas exchange was steeper for species that occupied lower elevations on average, suggesting it is possible that these two traits can evolve independently of each other despite being positively correlated. C_LI

evolutionary biology↗