Fig. 2

Orthology inference suggests substantial duplication in spiders and scorpions. a Distribution of orthology ratios from Orthologous Matrix analysis of full genomes. Comparisons of an arachnopulmonate genome to a 1X genome are shown in red and comparisons among 1X genomes are shown in yellow. A significantly higher number of 1:1 orthologs is recovered in pairwise comparisons within the non-arachnopulmonate genomes (P = 1.46 × 10^–3). b Magnification of the 1:2 ortholog ratio category in (a) shows a significantly higher number of duplicated genes in comparisons of spider or scorpion genomes to a 1X genome (P = 6.67 × 10^–4). c Distribution of orthology ratios for a subset of genes benchmarked as putatively single copy across Arthropoda (BUSCO-Ar). As before, a significantly higher number of 1:1 orthologs is recovered within the 1X genome group (P = 3.43 × 10^–8). d Magnification of the 1:2 ortholog ratio category in (c) shows a significantly higher number of duplicated genes in spiders and scorpions (P = 7.28 × 10^–9)