a signaling molecule (and yes, it was actually named after the character) and what it does is signal to the cells in a very early stage of development into what kind of feather they should turn (primary, contour, etc). But the super interesting part is that this molecule in birds was co-opted during evolution from the molecule that tells mammals which finger to grow where! How is that for cool?!https://www.eurekalert.org/pub_releases ... 043020.php
