DOI: 10.5061/dryad.z34tmpgng
title: Data from: Adapting to an increasingly stressful environment: Experimental evidence for ‘micro-evolutionary priming’

description: 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 generations.
 Compared to populations with an exposure history to copper, genotypes of
 control populations suffered strong growth reductions when exposed to
 intermediate and high levels of copper, mainly as the result of high
 mortality rates. Remarkably, when exposed to low copper levels, fitness
 differences between genotypes of control populations and populations
 adapted to these low levels were very small, whereas the latter strongly
 outperformed the first at intermediate and high copper levels. These
 results highlight the potentially strong but hitherto largely ignored
 impact of micro-evolutionary priming on the performance of populations in
 a changing environment. We discuss potential consequences of
 micro-evolutionary priming for the persistence of populations and the
 spatial eco-evolutionary dynamics of metapopulations.
description: 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 (corresponding with Cycles 2, 4 and 6,
 respectively). After an acclimation phase, demographic variables of
 experimental populations were monitored for 5 days. A
 reduced version of the common garden experiment was repeated to verify if
 actual Cu concentrations equaled targeted concentrations in each
 treatment.
description: # 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, 57.5, 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 (corresponding with Cycles 2, 4 and 6, respectively). After an acclimation phase, demographic variables of experimental populations were monitored for 5 days. These data are deposited here in the file: 'Microevolutionary_priming_demographics.csv' A reduced version of the common garden experiment was repeated to verify if actual Cu concentrations equaled targeted concentrations in each treatment. See: 'Microevolutionary_priming_copper.csv' This dataset consists of two files and one R-script (see ZENODO). Detailed explanation 'Microevolutionary_priming_demographics.csv' Grouping variables: Select_history: Treatment in the selection experiment (two levels: Control, Adapt) Cycle: cycle at the end of which clones were extracted from populations in the selection experiment (three levels: Cycle2, Cycle4, Cycle6) Treat: common garden treatment (three levels: Cu45, Cu57,5, Cu62,5) Day: day in the 5-day common garden experiment (levels: 1 to 5). Pop_Origin: Identity of experimental units in the evolution experiment (6 levels). Clone: identity of clone (36 levels) PopID: identity of experimental unit   Demographic variables (counts): FPE0: females with zero eggs FPE1: females with one parthenogenetic egg FPE2: females with two parthenogenetic eggs FPE3: females with three parthenogenetic eggs FUSE: mictic females with unfertilized sexual eggs FRE: females with resting egg FDEAD: dead rotifers LRE: loose resting eggs TotalF: total number of females at end of interval InitialF: total number of females at beginning of interval   Detailed explanation 'Microevolutionary_priming_copper.csv' Grouping variables: Treat: common garden treatment (three levels: Cu45, Cu57,5, Cu62,5) Replica: replicate Cu_addition: Cu-concentration aimed by the treatment Cu-concentration: Cu-concentration actually measured (µg L-1)