Figure 2: Branch-site analysis of positive selection.
From: The evolutionary history of genes involved in spoken and written language: beyond FOXP2
aBS-REL analysis for the CNTNAP2 (A) and FOXP2 (B) genes in mammals and birds, respectively. Branch lengths are scaled to the expected number of substitutions per nucleotide. Red: branches that were confirmed to be under episodic positive selection using the codeml branch-site models.
