Biology subjects

Skoracka, A.

Publications and source records attributed to Skoracka, A..

3 recordsLinked to original sources

bioRxiv2026

Biotic niche expansion constrains the fundamental abiotic niche: Evidence from experimental evolution

In an ever-changing world, organisms are subject to selective pressures that shape their ecological niches. Niche theory predicts that environmental heterogeneity selects for niche expansion, yet niches are inherently multidimensional, and expansion in one dimension may impose severe constrains on others. In this study, we employed rigorous experimental evolution to investigate these cross-dimensional trade-offs in the wheat curl mite, Aceria tosichella. By adapting replicated lineages to either stable (single-host) or alternating (two-host) environments for hundreds of generations, we successfully expanded the mites fundamental biotic host niche, enabling lineages to exploit diverse host species, including those unencountered during their evolutionary history. Crucially, however, this biotic generalization incurred a significant cost in the abiotic niche dimension. Lineages adapted to alternating hosts exhibited significantly reduced thermal tolerance compared to host specialists, which maintained superior performance across a wider thermal range. This trade-off appears to be driven by a combination of genetically based metabolic constraints and behavioral dispersal strategies. Our results provide compelling experimental evidence for the "Jack-of-all-trades is master of none" hypothesis across niche dimensions. We demonstrate that physiological trade-offs between biotic versatility and abiotic resilience strictly constrain the evolution of the multidimensional niche, with critical implications for forecasting species distributions and invasion potential under climate change.

ecology↗

bioRxiv2026

Genomic basis of adaptation to constant and fluctuating environments in a global pest of cereals

In agricultural systems, spatially and temporally heterogeneous environments are expected to favour the evolution of generalist pests and pathogens, yet the genomic mechanisms underlying niche-breadth expansion remain poorly understood. Here, we address this gap by assembling one of the smallest known eukaryotic genomes--from the global cereal pest Aceria tosichella--and by resequencing generalist and specialist populations which evolved in the lab on constant versus fluctuating hosts. A previous study demonstrated that generalist populations retained a wider niche, including the ability to exploit a refuge host, compared to specialist populations that showed a narrowing of the ecological niche. Genomic scans identified 640 SNPs that significantly differed in frequency between treatments, including a single highly differentiated 120-kbp region containing 13 genes. Allele-frequency shifts across many SNPs in this region paralleled phenotypic divergence in the ability to utilise refuge hosts, and gene annotations suggested their roles in starvation resistance and nutrient signalling. However, experimental validation of the top candidate gene did not support its strong direct effect on survival on the refuge host, implying a more complex, likely polygenic basis for adaptation. Consistent with this interpretation, numerous significant SNPs occurred outside the focal region, with enrichment for genes involved in xenobiotic transport, detoxification pathways, and ABC transporters. Together, these results indicate that generalism in A. tosichella relies on complex molecular mechanisms that enable survival on suboptimal or refuge hosts, relying to a considerable extent on the ability to deal with stress arising, for example, from toxic compounds present in suboptimal hosts.

evolutionary biology↗

bioRxiv2025

Is passive dispersal informed? - Experimental evidence for decision-making in phytophagous arthropods

Animals must acquire and decode information to make the right decisions. While active dispersers can evaluate habitats en route, passive dispersers can only control their departure timing. Although the passive strategy is ubiquitous among arthropods, the mechanisms behind their take-off decisions remain poorly understood. We tested whether host niche breadth shapes passive dispersal in phytophagous mites by exposing them to host-derived kairomones and measuring departure rates. Using experimentally evolved specialist and generalist lineages, we found that dispersal depends more on the context in which cues are encountered that on the kairomones themselves. Host specialisation strongly shaped responses: mites left plants more readily when exposed to unfamiliar hosts, with generalists dispersing over twice as often as specialists. Increased number of unfamiliar kairomones strongly inhibited generalists dispersal but barely affected specialists. This suggests specialists use environmental novelty to trigger exploration, whereas generalists need multiple cues to confirm host suitability, revealing a trade-off between host range and environmental sensitivity.

ecology↗