# Genomic responses to increased temperature and pollinator selection in Brassica rapa L

## TL;DR

This study shows how temperature and pollinator type together influence the genomic adaptation of Brassica rapa plants.

## Contribution

The paper quantifies the joint genomic effects of temperature and pollinator identity on plant adaptation.

## Key findings

- Warming strengthened selection in community-level pollination, especially in the hot-generalised treatment.
- Bumblebee pollination showed strong genomic change, but it was obscured by genetic drift.
- Butterfly pollination had minimal genomic response compared to other treatments.

## Abstract

Rapid environmental change reshapes both abiotic stress and biotic interactions, yet it remains unclear how these combined forces structure plants' genomic adaptation. In particular, the joint influence of temperature and pollinator identity, two ecological axes undergoing simultaneous global shifts, has rarely been quantified at genomic resolution.We resequenced Brassica rapa L. plants after a six‐generation evolution experiment, combining two temperature regimes (ambient vs hot) with three pollination treatments (bumblebee, butterfly, and mixed bumblebee–butterfly), and glasshouse control, to assess how these factors shape genomic responses.Using multiple complementary statistics (allele‐frequency trajectories, F
ST outliers, Cochran–Mantel–Haenszel tests, and local score analyses), we found that adaptive genomic responses differed sharply among pollinators and temperatures: warming strengthened selection in community‐level pollination, yielding the clearest signals in the hot‐generalised treatment; bumblebee pollination showed strong but drift‐obscured genomic change; and butterfly treatments exhibited minimal genomic response.Our findings demonstrate that pollinator identity and temperature interact nonadditively to produce distinct, highly context‐dependent adaptive trajectories. This work highlights the importance of accounting for demographic variation and ecological complexity when predicting evolutionary responses to climate‐driven shifts in species interactions.

Rapid environmental change reshapes both abiotic stress and biotic interactions, yet it remains unclear how these combined forces structure plants' genomic adaptation. In particular, the joint influence of temperature and pollinator identity, two ecological axes undergoing simultaneous global shifts, has rarely been quantified at genomic resolution.

We resequenced Brassica rapa L. plants after a six‐generation evolution experiment, combining two temperature regimes (ambient vs hot) with three pollination treatments (bumblebee, butterfly, and mixed bumblebee–butterfly), and glasshouse control, to assess how these factors shape genomic responses.

Using multiple complementary statistics (allele‐frequency trajectories, F
ST outliers, Cochran–Mantel–Haenszel tests, and local score analyses), we found that adaptive genomic responses differed sharply among pollinators and temperatures: warming strengthened selection in community‐level pollination, yielding the clearest signals in the hot‐generalised treatment; bumblebee pollination showed strong but drift‐obscured genomic change; and butterfly treatments exhibited minimal genomic response.

Our findings demonstrate that pollinator identity and temperature interact nonadditively to produce distinct, highly context‐dependent adaptive trajectories. This work highlights the importance of accounting for demographic variation and ecological complexity when predicting evolutionary responses to climate‐driven shifts in species interactions.