Project: Sex in the City (SIC)

Manuscript: Multivariate phenotypic divergence along and urbanization gradient

Authors: James S. Santangelo, L. Ruth Rivkin, Carole Advenard, and Ken A. Thompson

This project has been published in Biology Letters
Data is archived on Dryad

Abstract

A growing body of evidence suggests that natural populations can evolve to better tolerate the novel environmental conditions associated with urban areas. Invariably, studies of adaptive divergence in urban areas examine only one or a few traits at a time from populations residing only at the most extreme urban and nonurban habitats. Thus, whether urbanization is driving divergence in many traits simultaneously in a manner that varies with the degree of urbanization remains unclear. To address this gap, we generated seed families of white clover (Trifolium repens) collected from 27 populations along an urbanization gradient in Toronto, Canada, and grew them up to measure multiple phenotypic traits in a common garden. Overall, urban populations had later phenology and germination, larger flowers, thinner stolons, reduced cyanogenesis, greater biomass, and were more attractive to pollinators. Pollinator observations revealed near complete turnover between urban and nonurban sites, which may explain some of the observed divergence in floral traits and phenology. Our results suggest that adaptation to urban environments involves multiple organismal traits.

Using the code in this repository

To use the code in this repository to reproduce the manuscript's results, please follow the following steps:

1. git clone this repository or download it as a zip folder
2. Open Rstudio, go to file > Open project and open the SIC.Rproj Rproject associated with this repository
3. Run renv::restore() in your R console. Requires renv package (see THIS vignette)
4. The analyses can be prformed by running scripts/masterScript_analyses.R