Burga et al. could not identify gene regulatory regions which might contribute to flightlessness in the Galapagos cormorant. Using a bird-specific alignment we discover 48 limb enhancers showing strong accelerated evolution in P. harrisi, including enhancers of key cilia development, hedgehog signaling, and planar cell polarity genes, such as Prickle1, Twist2 and Ndk1, extending Burga's proposed mechanism into the non-coding genome.
Comment on “A genetic signature of the evolution of loss of flight in the Galapagos cormorant”