The leading edge matters too: fitness and the expression of adaptive differentiation are greatest at the high-elevation edge of a species range

This dataset contains raw and processed data from two common garden experiments testing local adaptation and fitness variation across the elevational range of Erythranthe laciniata (Phrymaceae), an annual monkeyflower endemic to the Sierra Nevada, California, USA. Experiments were conducted in 2009 and 2021 at low-, mid-, and high-elevation field gardens spanning the species’ distribution. The dataset includes survival and lifetime fitness measurements (total flower number), population and maternal line identifiers, geographic coordinates, elevation, climate data (NASA Daymet), and associated metadata. These data support analyses presented in Shay & Pennington et al. (2025), The leading edge matters too: fitness and the expression of adaptive differentiation are greatest at the high-elevation edge of a species’ range (Ecology Letters).
, Seeds were collected from 23 populations across the elevational range of E. laciniata using stratified random sampling of ≥60 maternal plants per site. To minimize maternal effects, a refresher generation was grown under controlled greenhouse conditions before planting into field common gardens. In 2009, three experimental gardens were established at low (1000 m), mid (1670 m), and high (3095 m) elevations in Fresno County, CA, with ~100–60 replicate individuals per population per garden. In 2021, three gardens were again established (1000 m, 1555 m, and 2500 m), with nine focal populations represented by 15 maternal lines and three replicates each. Blocks were randomized, overwintered naturally, and censused through flowering. Survival was scored as a binary outcome (flowered or not) and lifetime fitness was measured as the total number of flowers produced per plant. Climate data (mean daily minimum and maximum temperature, precipitation) were extracted from the NASA Daymet V4 dataset ..., , # Data from: The leading edge matters too: fitness and the expression of adaptive differentiation are greatest at the high-elevation edge of a species range

[https://doi.org/10.6071/M39T04](https://doi.org/10.6071/M39T04)

## Description of the data and file structure

This README file was generated on 2025-12-18 by Jackie Shay

## Data Description

### Dataset Title

The leading edge matters too: fitness and the expression of adaptive differentiation are greatest at the high-elevation edge of a species range

### Date of Data Collection

2008-2009 and 2020–2021

### Contributors

* Jackie E. Shay, Department of Ecology, Evolution, and Marine Biology, University of California, Santa Barbara, CA, USA
* Lillie K Pennington, Department of Genetics, University of Georgia, Georgia, GA, USA
* Daniel J. Toews, Environmental Systems Graduate Group, University of California, Merced, CA, USA
* Elizabeth Green, Department of Life and Environmental Sciences, University of California, Merced, CA, U..., , **Changes after Oct 27, 2025:** 

1. \`addlowmr_linear` is defined in multreg_figures_v2
2. \"tray\" was added back to the dfdata_V2 file

**Changes after Nov 19, 2025:** 

1. Updated R Markdown for ease of reader runs, including organization and naming of script chunks. 
2. Script updated for misaligned code. 
3. Duplicate and unused script removed. 

**Changes after Dec 18, 2025:** 

1. shay_pennington_leading_edge_v7.Rmd updated.