On my recent epigenetics post, Heraclides pointed me in the direction of an article about polydactyly in cats. It contains the comment that these cats are also known as mitten or thumb cats because they can learn to pick up things, open latches or move objects with near-human dexterity.
Well, OK, we had a cat who was pretty dextrous. He regularly opened the fridge (yes, all right, it was old & the door seals weren't too great, but still...) & he eventually became quite good at manipulating those lever-type door handles. But he did all that without benefit of 'thumbs'.
In polydactylous cats the extra digits tend to be added on the inner (not the 'pinky') side of the paw. I guess it's possible that there's some degree of 'folding' possible along the axis between 'normal' & extra digits, so these cats could well have a bit more flexibility in paw movement than a normal cat. But 'near-human dexterity'?
Cats are digitigrades - they walk & run on their toes. (Humans & bears are plantigrade, walking on the soles of their feet, while horses and deer - & elephants - are unguligrades & run on the tips of their toes.) The muscles associated with kitty toes will be arranged a bit differently than those in people and deer. And that includes the muscles that give a wide range of precise movements to the first digits on our forelimbs - our thumbs.
So I suspect that the claims about the abilities of polydactylous cats should perhaps be taken with a grain of salt. Fortunately. Otherwise we could be in real trouble...
I mean, from this...
to this? And our cats already think they rule the house!