Bill Nye the Science Guy (1993)
S03E18 Birds
Episode Overview
Researchers theorize that birds originated from reptiles. While birds possess backbones and reproduce by laying eggs, they have a distinctive characteristic that distinguishes them from all other creatures: feathers. These feathers are composed of keratin, the same protein found in human hair and nails. The combination of feathers, lightweight skeletal structures, robust wings, and strong cardiovascular systems enables birds to soar through the skies.