Why aren't all cats like mine?

[riley dieffenbach]

Paul, my cat, has been a member of my family for going on five years now. He was acquired from a shelter near Boston and like a fair number of New England cats is polydactyl. He sports full double paws in the front with normal back paws. The double paws are fully formed and fully functional. The result is that he can grip objects in a fair approximation of a human hand. If I put my finger into his paw he can grip it with surprising force. Something that my other cat is incapable of. This mutation makes him the most remarkable predator I have ever seen in the cat world. This paw configuration also seems to come in handy with climbing, stability, jumping and other cattish activities.

In an evolutionary sense it would seem to me that the more toes the better. More toes provide a more stable platform and a much larger trap for small furry creatures. This mutation is fairly common in cats so its not like wondering why humans don't have wings. Can anyone enlighten me as to why all cats have not developed muliple toes. Is there an evolutionary disadvantage that I am missing?

[Duck Duck Goose]

http://www.peteducation.com/isittrue/polydactyly.htm

Extra toes on a foot are common in cats but relatively rare in dogs. This condition is called polydactyly. Cats normally have five toes on each front foot and four toes on each hind foot for a total of 18 toes. If your cat has more than 18 toes, your cat is polydactyl. We've even seen cats with a total of 24 toes! Usually the extra toes are found on the front feet and some people refer to these as "double-pawed" cats.

See Why do we have five digits on each limb? and Is it true many New England cats have extra paws because Boston ships' captains considered them lucky?

Welcome to the Straight Dope!

[DaveRaver]

Evolution is an ongoing process. You may be witnessing the beginning of a new widespread trait developing, if polydactylism is a dominant trait.

[Wyvern]

Wow! That's a really unusual pet you have there! If your cat has been fixed, there is no chance that his unique anatomy can be passed on to his offspring, letting evolution "decide" about this new development. Evolution itself can be very slow, depending on the life span of the critters involved (i.e., a mutation can spread through a bacteria population with in a few weeks because they have a life span of a couple of hours or days, humans live for decades, so many changes develope slowly). Also, genetic mutations are very rare, which adds to the slow change factor. You never know, if Paul's paws are as amazing as you say, and he has some siblings carrying the genes for this trait (since you got him at a shelter, I'd bet he has at least one out there somewhere), we may be hearing about six-pawed cats.
On an similar note, I have a three-legged cat, named Elwood (he has a buddy named Jake). He lost his right hind leg as a kitten. He is now 2 years old and gets around fine. Most people have to do a paw count to realize he's lost a limb.

[Baraqiyal]

Just a WAG… I don’t see how the domestic housecat can possibly continue to evolve given that they no longer have to struggle to survive the way wild animals do. Also, breeders will likely try to breed out anything unusual.

[riley dieffenbach]

Paul is rather an amazing animal. I would agree that the domestic house cat is likely not still evolving. It would seem however, that this is a significant evolutionary advantage. I almost feel sorry we neutered him (and I'm sure he does too).

[Commander Fortune]

Originally posted by Baraqiyal
Also, breeders will likely try to breed out anything unusual.

There are breeders out there who breed for polydactylism.

[AWB]

Originally posted by Commander Fortune

There are breeders out there who breed for polydactylism.

True. There was one woman who actually overbred polydactylism to the point that the cats' front legs were basically useless. The poor things had to hop around like rabbits. She called them "twisty cats"; I called her twisted.

[Lynn Bodoni]

Wow! That's a really unusual pet you have there!

Not really. While it's not common, it's not really that rare, either.

Just a WAG… I don’t see how the domestic housecat can possibly continue to evolve given that they no longer have to struggle to survive the way wild animals do. Also, breeders will likely try to breed out anything unusual.

This is untrue. First of all, there are (quite unfortunately) large populations of feral cats who breed freely. They DO have to struggle to survive. There's also people (again, quite unfortunately) who don't get their cats altered, so that these cats are breeding under no supervision. Kittens are adorable, I'm a sucker for them, I could play with them all day...but there's a limit (which varies for each household) for the number of cats that can reasonably be accommodated in each human household. And it's very easy to reach that limit, if the household is not confining itself to just one or two sorts of purebred cats.

Breeders, in fact, WILL breed for unusual traits. For instance, the Scottish Fold (its ears fold down onto its head) is a fairly new breed. The curly coated cats (there's two varieties) were deliberately bred from one mutation. Now, there's things that are considered flaws in a breed (for instance, Siamese cats sometimes have crossed eyes or kinks in the tail, both of which are considered undesirable) and if a purebred cat has these flaws, it isn't likely to be bred or shown. But breeders are always looking for new and unusual traits to breed. In the case of Twisty Cats and Munchkins, I think that they are too eager for new traits. But that's more of a Great Debate.

There are a few breeders, too, who will intentionally cross domestic cats with wild cats, such as the serval cat of Africa. Thus, new genes are getting introduced to the pool of the domestic cat.

Incidentally, despite their reputations as being loners, most cats do better if they have at least one feline companion.

[Commander Fortune]

Originally posted by AWB

True. There was one woman who actually overbred polydactylism to the point that the cats' front legs were basically useless. The poor things had to hop around like rabbits. She called them "twisty cats"; I called her twisted.

Yeah - she breeds horses too. Fellow lurker and sometimes poster and fabulous friend Jett and I wrote her an e-mail asking if she could breed us a twisty hose that hopped around like a kangaroo - cause that would look cool. right? right?

She didn't respond.

[Commander Fortune]

Er..a twisty horse - I mean

[Zebra]

When I read the subject line I didn't know if you were bragging or complaining.