Genomic signatures of adaptation across a precipitation gradient from niche center to niche edge

Evaluating the potential for species to adapt to changing climates relies on understanding current patterns of adaptive variation and selection, which might vary in intensity across a species’ niche, hence affecting our inference of where adaptation might be most important in the future. Here, we investigate the genetic basis of adaptation in Lactuca serriola along a steep precipitation gradient in Israel approaching the species’ arid niche limit and use candidate loci to inform predictions of its past and future adaptive evolution. Environmental association analyses combined with generalized dissimilarity models revealed 108 candidate genes showing non-linear shifts in allele frequencies across the gradient, with 66% of these genes under strong selection near the dry niche edge. We detected selection acting on genes with separate suites of biological functions, specifically related to phenology and responses to environmental stressors, including osmotic stress, at the dry niche edge, ..., , , # Genomic signatures of adaptation across a precipitation gradient from niche center to niche edge

[https://doi.org/10.5061/dryad.v6wwpzh68](https://doi.org/10.5061/dryad.v6wwpzh68)

## Usage notes

Below find a list of file types and examples of how to open or work with them outside of R. 

.csv files can be opened and manipulated with Microsoft Excel, Google Sheets, or a plain text editor.

.vcf.gz (compressed Variant Call Format (VCF)) files can be read into R using the function *read.vcfR* through the *vcfR* package, or through programs such as [BamSeek](https://code.google.com/archive/p/bamseek/) or [BCFtools. ](https://github.com/samtools/bcftools)

## Description of the data and file structure

Low-coverage whole genome sequencing was conducted on leaf samples of 21 *Lactuca serriola* populations sampled in 2020, spanning Israel's steep precipitation gradient. 

### Files and variables

#### File: 108\_SNP\_ GDM\_orthologs.csv

**Description:** List of 108 SNPs retained after t...,