Neoteny / Juvenilization
Some dogs look and act forever young
Like puppies, the adult dogs of many breeds are small, with short snouts,
floppy ears, and large eyes. Scientists call these puppy-like features
neotenic -- most of us just call them cute.
Puppy-like behaviors -- playing, nuzzling, frolicking -- also appeal
to many of us, and even elicit our care. If behavior and appearance
are genetically linked, then breeding for one may bring the other.
Long nose, short nose -- depends on how the skull
grows!
The skull of a wolf or dog pup is about as wide as it is long. But
as the pup grows, the shape of its head changes. An adult dog's head
is usually much longer than it is wide because later in development,
growth in skull length overtakes that of skull width, such as the Airedale
to the left.
However, some breeds continue to grow like young puppies for a longer
period. In short-snouted breeds, the snout grows more slowly in length
than in width and may stop early, resulting in adults with puppy-like
faces, such as the French bulldog to the right.
Long-snouted breeds are born with typical puppy proportions, but their
skull grows more rapidly in length than it does in width. Growth in
skull length overtakes width earlier in development and they end up
with longer noses, such as the Saluki to the left.
