Biology subjects

Meziere, Z.

Publications and source records attributed to Meziere, Z..

3 recordsLinked to original sources

bioRxiv2026

Heatwave winners and losers: cryptic coral holobionts differ in thermal tolerance

Extreme climatic events are reshaping ecosystems worldwide as individual organisms vary markedly in their ability to withstand these disturbances. Deciphering patterns of persistence on local scales is therefore critical for predicting biodiversity trajectories under intensifying climate extremes. In this study, we examined variation in thermal stress responses among individuals of the coral Stylophora pistillata species complex during a heatwave at Heron Island Reef, Australia. More than half of the focal coral colonies died on the reef, and survival of coral fragments maintained under ex situ common thermal stress conditions was significantly correlated with the survival of their source colony. This demonstrates that survival differences result largely from biological factors rather than differential thermal exposure across reef habitats. Under common garden conditions, we observed striking differences in bleaching severity and survival times among three sympatric cryptic taxa and their highly host-specific symbiont community. Within the most locally common taxon, corals from historically warmer and more seasonally variable reef habitats seem more susceptible to bleaching, contrary to expectations. Together, these results reveal how biological differences among cryptic taxa and among individuals can shape coral responses during a heatwave and advance our understanding of coral vulnerability in a rapidly warming world.

ecology↗

bioRxiv2026

Localised admixture triggers parallel adaptation in a coral species trio on the Great Barrier Reef

Hybridisation can shape evolutionary trajectories and fuel rapid adaptation. Yet, whether adaptive introgression repeatedly reconfigures genomes in predictable ways remains largely unknown. Here, we show that three-way admixture drives repeatable parallel differentiation in reef-building corals in the Acropora hyacinthus species complex. Adaptive introgression is confined to the southern Great Barrier Reef, where admixture timing coincides with a recent breakdown in species barriers despite limited historical gene flow. Genome-wide introgression is characterised by numerous shared minor-parent ancestry peaks that are enriched for stress-response genes and under positive selection for parallel adaptive admixture. Our results demonstrate that introgressive hybridisation can be geographically restricted between sympatric marine species and can promote repeated rapid adaptation that transcends species boundaries.

evolutionary biology↗

bioRxiv2026

Genomic repeatability and predictability of local (mal)adaptation in a reef-building coral

Climate change is a growing threat to biodiversity, and the persistence of populations largely depends on their capacity to adapt to changing environmental conditions. Although there is an urgent need to forecast local adaptive potential, it is unclear how such predictions are affected by the genomic architectures underlying local adaptation across a species range. In this study, we examine the genomic basis of local adaptation of the short-distance dispersing coral Stylophora pistillata, sampled at forty-six sites across eight reefs of the Great Barrier Reef, Australia. Our results show that thermal adaptation for this species involves hundreds of genomic loci with combinations that differ across geographic regions. Although adaptive loci were largely region-specific, genotype-environment relationships estimated across the entire range could predict regional-level adaptive patterns. This shows that genome-wide sequence data combined with geographically broad sampling can support reliable evolutionary forecasting. Under climate change projections, predicted shifts in genotype-environment associations were highly spatially variable, both between and within geographic regions. While some populations might be sufficiently adapted for moderate (SSP1-2.6 and SSP2-4.5) climate warming by 2050, up to 30% may face severe maladaptation risk by 2100 under a high-emission (SSP5-8.5) scenario. Collectively, these findings offer new insights into the spatial distribution of coral adaptive potential and how it might shape corals resilience in a warming ocean.

evolutionary biology↗