Is carotenoid ornamentation linked to the inner mitochondria membrane potential? A hypothesis for the maintenance of signal honesty

► Ubiquinone and carotenoids may share common functionality and oxidative pathways. ► Carotenoids may undergo sequential oxidation in the inner mitochondria. ► Coq enzymes may ketolate, O-methylate and saturate carotenoids to ornaments. ► Mitochondria oxidation may link signal honesty with redox and energy efficiency.