In this charming video, a magician offers a treat to various dogs and then spirits it away just under their noses.
If you're a dog person who knows a little bit about the temperaments of different breeds, this video contains some interesting moments. Note how some food-motivated breeds immediately search for the missing treat. Others, such as the german shepherd (0:31), look instead at the people around them, opting to gather information using their hardwired social connection to human beings.
Dogs represent one of the most successful human experiments in genetic engineering, one that began millennia before we understood the mechanism by which traits are propagated from one generation to another. We were bonded with dogs before we figured out how to farm. Insofar as proto-dogs conferred a selective advantage on those humans who took an interest in their care, they may have co-evolved with our own ancestors and encouraged the proliferation of human genes that encode a fondness for domestic animals.
An experiment in which foxes were domesticated over 35 generations showed that promoting tameness also led to the development of unrelated traits such as certain coat patterns, floppy ears, and barking vocalizations. It also may favor neoteny.
I've never loved floppy-eared dogs as much as I like pointy-eared dogs (we have german shepherds), so I guess I prefer a less domesticated phenotype.