Limits to the evolution of herbicide escape and tolerance in the agricultural weed Amaranthus palmeri

In response to novel anthropogenic stresses, defense strategies including resistance, tolerance, and escape can evolve. However, if the evolution of one or more of these strategies is limited by weak natural selection or a lack of genetic variation, then a mixed strategy (e.g. resistance and tolerance) is unlikely to evolve. To determine the mechanisms that limit the evolution of defense strategies, we studied escape from and tolerance to glyphosate herbicide in Amaranthus palmeri, an agricultural weed that has evolved glyphosate resistance. We grew A. palmeri in fields planted with corn, soybean, or no crop; manipulated their exposure to glyphosate; and measured escape and tolerance. We did not detect selection or genetic variation for glyphosate escape in any agricultural environment, suggesting that a mixed strategy of resistance and escape is unlikely to evolve in A. palmeri. We also did not detect selection for glyphosate tolerance, but there was genetic variation for tolerance in ..., , , # Limits to the evolution of herbicide escape and tolerance in the agricultural weed Amaranthus palmeri Dataset DOI: [10.5061/dryad.8kprr4xwg](10.5061/dryad.8kprr4xwg) ## Description of the data and file structure Data and code for: Limits to the evolution of herbicide escape and tolerance in the agricultural weed *Amaranthus palmeri*. Submitted to Evolution. This package contains 14 files: 1\. “**survival.2017.csv**”: This file contains the data used to estimate selection on days to seedling emergence via survival for *Amaranthus palmeri* grown in 2017 a cultivated soybean field (Fig. 1; Table S2). The columns are as follows: -position: Unique number identifying each plant included in the data set -block: Identity of the field where each experimental plant was located (A, B, or C) -population: Identity of the population (Table S1) that an open-pollinated maternal family was collected from (HE (41.447092 -90.141592); CH (40.074505 -88.246533); EF (39.228864 -88.525873); MD-IL ...,