Adapting to an increasingly stressful environment: Experimental evidence for ‘micro-evolutionary priming’

In many natural systems animal populations are exposed to increasing levels of stress. Stress levels tend to fluctuate and long-term increases in average stress levels are often accompanied by greater amplitudes of such fluctuations. Micro-evolutionary adaptation may allow populations to cope with gradually increasing stress levels but may not prevent their extirpation during acute stress events unless adaptation to low stress levels also increases their tolerance to acute stress.
We tested this idea, here called ‘micro-evolutionary priming’, by exposing populations of the monogonont rotifer species Brachionus calyciflorus to four levels of copper stress (control, low, intermediate and high) during a multigenerational selection experiment. Subsequently, in a common garden experiment we exposed randomly selected subsets of genotypes (clones) of each of these populations to low, intermediate and high copper levels and assessed their population growth performance across multiple gener..., We conducted a selection experiment followed by a common garden experiment. In the selection experiment, we exposed 6 genetically identical populations of the freshwater monogonont rotifer Brachionus calyciflorus s.s.to two treatments, i.e. a copper addition treatment and a copper free control treatment. All populations underwent six cycles (Cycles 1 to 6); during each cycle clonal population growth was followed by sexual reproduction and the formation of dormant propagules. Dormant propagules produced during each cycle were stored and partly used to start up the next cycle. In the copper addition treatment, copper levels were stepwise increased at the beginning of each cycle (from 30, 45, 50, 55, 57.5, 60 to 62.5 µg Cu/L in Cycles 1 to 6, respectively).
For the common garden experiment, we established two clonal lines from dormant propagules for each population at the end of Cycles 2, 4 and 6. Populations of all clonal lines were subjected to concentrations of 45, 57.5 and 62.5 µg Cu/L..., , # Data from: Adapting to an increasingly stressful environment: Experimental evidence for ‘micro-evolutionary priming’

[https://doi.org/10.5061/dryad.z34tmpgng](https://doi.org/10.5061/dryad.z34tmpgng)

## Description of the data and file structure

Brief overview experimental procedures:

We conducted a selection experiment followed by a common garden experiment. In the selection experiment, we exposed 6 genetically identical populations of the freshwater monogonont rotifer Brachionus calyciflorus s.s.to two treatments, i.e. a copper addition treatment and a copper free control treatment. All populations underwent six cycles (Cycles 1 to 6); during each cycle clonal population growth was followed by sexual reproduction and the formation of dormant propagules. Dormant propagules produced during each cycle were stored and partly used to start up the next cycle. In the copper addition treatment, copper levels were stepwise increased at the beginning of each cycle (from 30, 45, 50, 55, 57...