Data from: Intergenerational effects of dietary changes on trait means and variance
Data files
Sep 03, 2025 version files 126.88 KB
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Analysis_Script_2025_v2.R
39.89 KB
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Data.csv
83.73 KB
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README.md
3.25 KB
Abstract
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.
Dataset DOI: 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.