Data from: The evolution of peafowl and other taxa with ocelli (eyespots): a phylogenomic approach

The most striking feature of peafowl (Pavo) is the males' elaborate
train, which exhibits ocelli (ornamental eyespots) that are under sexual
selection. Two additional genera within the Phasianidae (Polyplectron and
Argusianus) exhibit ocelli, but the appearance and location of these
ornamental eyespots exhibit substantial variation among these genera,
raising the question of whether ocelli are homologous. Within
Polyplectron, ocelli are ancestral, suggesting ocelli may have evolved
even earlier, prior to the divergence among genera. However, it remains
unclear whether Pavo, Polyplectron and Argusianus form a monophyletic
clade in which ocelli evolved once. We estimated the phylogeny of the
ocellated species using sequences from 1966 ultraconserved elements (UCEs)
and three mitochondrial regions. The three ocellated genera did form a
strongly supported clade, but each ocellated genus was sister to at least
one genus without ocelli. Indeed, Polyplectron and Galloperdix, a genus
not previously suggested to be related to any ocellated taxon, were sister
genera. The close relationship between taxa with and without ocelli
suggests multiple gains or losses. Independent gains, possibly reflecting
a pre-existing bias for eye-like structures among females and/or the
existence of a simple mutational pathway for the origin of ocelli, appears
to be the most likely explanation.