design: DNA was extracted from all tissues using a Qiagen DNeasy Blood and Tissue Kit (Qiagen, Inc.) and quantified using a Qubit dsDNA BR assay kit (Thermo Fisher, Waltham, MA). We prepared two reduced representation genomic libraries following a modified version of the double-digest RADseq (ddRAD) protocol (Peterson et al. 2012, as modified by Barley et al. 2019) and sequenced on an Illumina NovaSeq 6000 Lane (100SR, 10X chemistry) with one library per lane.