In a wonderfully animated episode of the NPR series SkunkBear, host Adam Cole amiably explains the physiology that causes many a domesticated dog to possess both floppy ears, shorter snouts and spotted patterns more so than their ancient ancestors. The specific question of these specific features proved quite vexing to Charles Darwin, even as he was writing The Origin of Species, but Swiss anatomist Wilhelm Hiss has already discovered the function of neural crest cells in these features.
Meural crest cells show up very early in the early in the development of all vertebrate embryos …some of these cells end up right here above the kidneys. They become cells that secrete adrenaline that famous fight-or-flight form. Wild animals are always fighting or fleeing to survive and that makes it hard for humans to get close but what if an animal was born with fewer of these neural crest cells…that animal would have less adrenaline. It would probably be less freaked out by humans and it would pas that behavior on to its offspring.
When you look at tame animals (like Darwin did) you start to notice a pattern – the ears of our pets and livestock droop a lot more than their wild counterparts. Why on earth would that be? https://t.co/2Q76kJUDwT pic.twitter.com/JZHZdQWbgx
— Skunk Bear (@NPRskunkbear) January 31, 2018