DOI: 10.5061/dryad.q573n5tvw
title: Data from: Intergenerational effects of dietary changes on trait means and variance

description: Environmental stress can alter not only trait means but also trait
 variances—an often-overlooked yet evolvable feature with ecological and
 evolutionary relevance. Here, we examine how dietary stress affects both
 the mean and variance of morphological and reproductive traits across two
 generations in clonal Daphnia. Using a factorial design, we manipulated
 maternal and offspring environments with high- (algae) or low-quality
 (cyanobacteria) diets, measuring eye size, body size, and reproductive
 output in eight genotypes. Morphological trait means showed consistent
 treatment-by-generation interactions: low-quality diets reduced trait
 size, with partial recovery upon re-exposure to high-quality food.
 Reproduction was determined largely by current conditions, while eye and
 body size showed legacy effects of maternal environment. Trait variance
 patterns were trait-specific and not uniformly linked to mean responses:
 eye size variance declined under stress, body size variance increased
 across generations, and reproductive variance peaked in offspring released
 from maternal stress. We also developed a conceptual framework that
 specifically considered roles for condition transfer, anticipatory
 plasticity, and diversified bet-hedging as potential mechanisms underlying
 these intergenerational impacts on traits and variances. Although no
 single mechanism explained all outcomes, our findings support condition
 transfer and suggest potential co-occurrence of multiple strategies. This
 data and script supports the associated article and contains all the
 relevant information to replicate the study.
description: # Data from: Intergenerational effects of dietary changes on trait means
 and variance Dataset DOI:
 [10.5061/dryad.q573n5tvw](10.5061/dryad.q573n5tvw) ## Description of the
 data and file structure For the full experimental description, please see
 the associated manuscript. In short, *Daphnia* *pulicaria* were collected
 from Lake Kegnosa (42° 58' N, 89° 14' W) between the 5th and
 20th of May 2022 and isolated to produce clonal lines. Approximately 15
 individuals from each clone and second generation were placed into each
 treatment group; AA, CA and CC. AA individuals were initially exposed to
 algae, and their daughters are also exposed to algae. CA individuals were
 first exposed to cyanobacteria, but their daughters were supplied algae.
 CC individuals were exposed to cyanobacteria over both generations. Using
 ImageJ, we measured body and eye size. We also recorded the number of
 offspring produced across the first 4 clutches.  ### Files and variables
 #### File: Analysis_Script_2025_v2.R **Description:** Analysis script to
 reproduce both the analyses and figures produced for the associated
 manuscript. #### File: Data.csv **Description:** Data supporting the
 analysis script and associated manuscript.  ##### Variables * ID: The
 individual identity (character string)  * Clone: The clonal lineage
 identity (numerical) * Generation: The generation of the focal individual
 (factor, either 2 or 3)  * Replicate: The identity of the individual
 within the clone and generation (numerical)  * Treatment: The designated
 treatment group (AA: Exposed to algae in both generation 2 and 3, CA:
 Exposed to cyanobacteria in generation 2 and algae in generation 3, CC:
 Exposed to cyanobacteria for both generations) * age: The day at which the
 morphological measurements were recorded (missing values = NA) *
 body.area: The area of the body (mm2; missing values = NA) * body.feret:
 The length of the body (mm; missing values = NA) * stand.body.feret: The
 individual body length minus the average body length divided by the body
 length standard deviation (missing values = NA) * eye.area: The area of
 the eye (mm2; missing values = NA) * eye.feret: The length of the eye (mm;
 missing values = NA) * stand.eye.feret: The individual eye length minus
 the average eye length divided by the eye length standard
 deviation (missing values = NA) * clutch1: The count of offspring produced
 in the first clutch (missing values = NA) * clutch2: The count of
 offspring produced in the second clutch (missing values = NA) *
 clutch3: The count of offspring produced in the third clutch (missing
 values = NA) * clutch4: The count of offspring produced in the fourth
 clutch (missing values = NA and blank) * date_c1: The date at which the
 first clutch was produced (missing values = NA) * date_c2: The date at
 which the second clutch was produced (missing values = NA) * date_c3: The
 date at which the third clutch was produced (missing values = NA) *
 date_c4: The date at which the fourth clutch was produced (missing values
 = NA and blank) ## Code/software Any software capable of opening a .csv
 file will allow for the viewing of the data. To use the code that will
 reproduce the analyses and figures, R v4.4.2 or above is required.