title: Evolution. How birds got their beaks.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Pennisi
mesh_terms: D000818:Animals; D001502:Beak / Q000033:anatomy & histology* / Q000196:embryology; D005075:Biological Evolution; D001717:Birds / Q000033:anatomy & histology* / Q000196:embryology / Q000235:genetics*; D001842:Bone and Bones / Q000033:anatomy & histology / Q000196:embryology; D051524:Fibroblast Growth Factor 8 / Q000235:genetics*; D005580:Fossils; D053823:Hedgehog Proteins / Q000235:genetics*
chemical_list: D053823:Hedgehog Proteins; D051524:Fibroblast Growth Factor 8