A lack of genetic diversity and minimal adaptive evolutionary divergence in introduced Mysis shrimp after 50 years

The successes of introduced populations in novel habitats often provide powerful examples of evolution and adaptation. In the 1950’s, opossum shrimp (Mysis diluviana) individuals from Clearwater Lake in Minnesota, USA were transported and introduced to Twin Lakes in Colorado, USA by fisheries managers to supplement food sources for trout. Shrimp were subsequently introduced from Twin Lakes into numerous lakes throughout Colorado. Because managers kept detailed records of the timing of the introductions, we had the opportunity to test for evolutionary divergence within a known time interval. Here, we used reduced representation genomic data to investigate patterns of genetic diversity and test for genetic divergence between populations and for evidence of adaptive evolution within the introduced populations in Colorado. We found overall very low levels of genetic diversity across all populations, with evidence for some genetic divergence between the Minnesota source population and the in..., , , # A lack of genetic diversity and minimal adaptive evolutionary divergence in introduced Mysis shrimp after 50 years

## Description of the data and file structure

**blast_fasta_RDA.fasta** 350 bp consensus sequences around each candidate SNP flagged by redundancy analysis.

**blast_fasta_pcadapt.fasta** 350 bp consensus sequences around each candidate SNP flagged by PCADAPT. Note some of the reads were flagged as truncated by samtools

**mysis_clean_10_for_neutral_popstats.vcf** 3,803 SNPs generated following the recommendations of Schmidt et al. 2021 for popualtion genetic statistics. None of these SNPs were found in the adaptive SNP list from PCAdapt, or RDA, so they are likely unbiased by strong FST outliers or selection.

**mysis_clean_imputed_names_fix.vcf** 18,441 SNPs imputed in Linkimpute that were used for redundancy analysis, PCAdapt, and SNMF.

**mysis_clean_imputed_neutral_names_fix.vcf** 18,220 putative neutral SNPs with SNPs flagged as FST outliers from PCAdapt filtere...