Intergenerational effects of dietary changes on trait means and variance

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..., , # 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...,

环境胁迫不仅可以改变性状均值，还能改变性状方差——这是一个常被忽视但具备生态与进化意义的可演化特征。本研究以克隆型水蚤为对象，探究了饮食胁迫如何影响两代个体的形态与繁殖性状的均值与方差。本研究采用析因设计，以高营养（藻类）或低营养（蓝藻）饮食调控母代与子代的生长环境，并对8个基因型的个体进行眼大小、体大小与繁殖产出的测量。形态性状均值呈现出一致的处理×世代交互效应：低营养饮食会降低性状尺寸，当重新暴露于高营养食物后，性状尺寸会得到部分恢复。繁殖能力主要由当前生长环境决定，而眼大小与体大小则表现出母代环境的遗留效应。性状方差模式具有性状特异性，并不与均值响应保持一致关联：胁迫条件下眼大小的方差降低，而体大小的方差在……
# 数据来源：饮食变化对性状均值与方差的代际效应
数据集DOI：10.5061/dryad.q573n5tvw

## 数据与文件结构说明
完整实验方案详见相关研究论文。简言之，本研究于2022年5月5日至20日从凯格诺萨湖（Lake Kegnosa，北纬42°58′，西经89°14′）采集了蚤状溞（Daphnia pulicaria），并通过分离培养建立克隆系。每个克隆系的第二代约15个个体被分配至AA、CA、CC三个处理组：AA组个体初始暴露于藻类饮食，其子代同样暴露于藻类饮食；CA组个体初始暴露于蓝藻饮食，但其子代则喂食藻类；CC组个体在两代均暴露于蓝藻饮食。本研究使用ImageJ软件测量体大小与眼大小，并记录了个体前4窝的繁殖后代数量。

### 文件与变量
#### 文件：Analysis_Script_2025_v2……