Feathers are amazing evolutionary innovations that allowed birds to conquer the sky. A study led by Matthew Towers (University of Sheffield, UK) and Marian Ros (University of Cantabria, Spain) and published in the journal Development now reveals that flight feather identity is established thanks to Sonic hedgehog—a signalling molecule well-known for giving the digits of the limb their different identities (so that your thumb is different from your pinky, for example). These findings suggest the pre-existing digit identity mechanism was co-opted during the evolution of flight feathers, allowing birds take to the air.
Click here for original story, Birds take flight with help from Sonic hedgehog
Source: Phys.org