Leave a piece of cake within your dog's reach, and it's a safe bet that your pooch will gobble it up. Leave a piece of cake within your cat's reach, and your cat may knock the cake around for kicks, but kitty isn't going to devour the cake.

Cats are finicky eaters, sure, but did I mention that this is one heck of a good piece of cake? What's the cat's problem?

It appears that cats can't taste sweetness and therefore aren't attracted to it. A gene that plays a vital role in the creation of sweet receptors on the tongues of other mammals is defective in both domestic cats and big cats. The defective gene does not produce a protein that is crucial to the production of sweet receptors.

Because the gene presumably once produced this protein, but doesn't any longer, it's akin to a molecular fossil. The name for such a gene is pseudogene. It's similar to genes involved in eye development in blind cave fish and limb development in whales, as well as vestigial traits in other organisms.

The discovery of this pseudogene now has scientists wondering what came first, the loss of sweet receptors or carnivorous behavior. It could be that the loss of the ability to taste sweetness drove cats to eating nothing but meat or it could be that as cats became carnivorous, they eventually lost the unused sweet receptors.

Either way, you can rest assured that you can leave a smorgasbord of sweets on the kitchen counter, and your cat won't beat you to them, except to play soccer with them maybe.