Change in threespine stickleback defensive traits, following brook trout introduction

In recent decades, numerous observations have been made of evolution induced by anthropogenic change in natural populations. Evolution in response to harvest, climate change, pollution, landscape change, and introduced invasive species is common. In the article \"Evolution of threespine stickleback (Gasterosteus aculeatus) defensive traits following the stocking of brook trout (Salvelinus fontinalis)\" in the American Naturalist, we provide evidence for evolution in a new context by documenting a large increase in the frequency of defensive pelvic spines in two unusual threespine stickleback (Gasterosteus aculeatus) populations previously shown to mostly lack such structures. These populations, in Parc national du Lac-Témiscouata, Québec, Canada, were historically free of predatory fish and consisted nearly entirely of pelvic-spineless stickleback. This phenotypic change coincided with the stocking of the lakes with brook trout (Salvelinus fontinalis), a stickleback predator, and the intr..., , # Change in threespine stickleback defensive traits, following brook trout introduction

#### Description of the data and file structure

Code file: Temiscouata-Nat_hist_note_tr.Rmd

Data files: Temiscouata_nat-hist-note_8-25-25update.csv, Rond-Croche-aFoin_stocking_submission_tr.csv, Tem-water-condition.csv (not necessary for analyses, but shown in Table S1)

**Details for Temiscouata_nat-hist-note_8-25-25update.csv**:

Individual-level specimen data. Includes columns for: Lake, collection date (Date), collection year (Year), Individual ID number (ID), standard length in mm (SL), plate morph including asymmetric completes (PlateMorph), pelvic spine number (PSpineNum), L_Spine, R_Spine, and Avg_Spine (lengths in mm of left pelvic spine, right pelvic spine, and average of the two pelvic spines), Plate_count (count of plates from LaCasse & Aubin-Horth 2012), sex determined by dissection (Sex_gonads), museum accession number for data from Edge & Coad (1983), presence or absence of *Schisto...,