I think you're referring to recent articles like this one in which Dr. John Bradshaw, one of my favorite cat scientists, supposedly says that your cat thinks that you are a cat, too.

I'm fairly sure that is not what he's actually saying. It's another example of why we have to be careful of the way popular media reports scientific findings. Bradshaw is not saying that your cat actually thinks you are some freak mutant furless cat. What he is saying is that your cat uses some of the same signals to communicate with you as it would with other cats (tail up, allorubbing, etc.) Furthermore, the way cats communicate with their owners is more consistent with the way kittens communicate with their mothers than the way adult cats communicate with other adult cats.

If I were to weigh in on the "what your cat actually thinks you are" issue- which of course we'll never really know the answer to; we can't be inside the brain of a cat- I'd say that as much as a cat is able to create categories, it would definitely have a separate cat and human category. Humans and cats look very different and behave very different regardless of whether or not the cat uses a similar set of social signals to communicate with both groups. And again, the signals that cats use with other cats and that they use with humans do have different nuances to them.

To bring it around, my cat not only uses tail up and allorubbing with me- she also uses it with my dog. It's not that she thinks my dog is another cat- it's what exists in her suite of communicative gestures.

Mind you, individual cats can also develop their own unique ways to communicate when the traditional ones aren't cutting it.

To the second part of your question- as to whether or not cats can "sense" our emotions- I'm not entirely sure what you mean. Can you "sense" human emotions? You probably can, as far as understanding body language, tone of voice, etc. goes, not to mention you have the ability to understand the words when somebody says that they are happy. Cats can easily learn to do the same things (sans understanding most spoken language). And again, this isn't just a cat-human thing; cats can learn to understand the body language of other animals they live with like dogs. Just like you've learned to understand the body language of your cat.

Further Reading

Cat Sense by John Bradshaw

Cafazzo, S., & Natoli, E. (2009). The social function of tail-up in the domestic cat (Felis silvestris catus). Behavioural Processes, 80(1), 60-66.

Cameron-Beaumont, C. (1997). Visual and tactile communication in the domestic cat (Felis silvestris catus) and undomesticated small-felids. University of Southampton.  

McComb, K., Taylor, A. M., Wilson, C., & Charlton, B. D. (2009). The cry embedded within the purr. Current Biology, 19(13), R507-R508.

Miklósi, Á., Pongrácz, P., Lakatos, G., Topál, J., & Csányi, V. (2005). A Comparative Study of the Use of Visual Communicative Signals in Interactions Between Dogs (Canis familiaris) and Humans and Cats (Felis catus) and Humans. Journal of Comparative Psychology, 119(2), 179-186. doi: 10.1037/0735-7036.119.2.179

Nicastro, N. (2004). Perceptual and Acoustic Evidence for Species-Level Differences in Meow Vocalizations by Domestic Cats (Felis catus} and African Wild Cats (Felis silvestris lybica). Journal of Comparative Psychology, 118(3), 287-296. doi: 10.1037/0735-7036.118.3.287

For traction in their rear paws. Cats do the wiggle right before they pounce, which as we know is a forward leap. They don't want to slip when they're pushing off with their hind legs, so they dig their rear claws into the dirt (or whatever surface they are on) to get a solid grip.

Or, in shorter words, cats do the butt wiggle so that this doesn't happen:

To the first question: cats are animals that hunt by ambush- they sneak up on their prey. Compare that to animals like large canids, which generally hunt by coursing- they run down their prey until it is exhausted.

(Within the cats, cheetahs are an obvious exception to this.)

Also consider the fact that cats are on the small side, and their ancestor, the African wildcat, lived in an area with a LOT of larger predators. If you consider these two facts, you can understand why it would be beneficial for the domestic cat to evolve ways to move very quietly.

Now, as to HOW they do it, there are a number of mechanisms. First, their gait. When cats walk, they place their back foot almost directly into the same spot they put their front foot. You can see it in the doubled-up pawprints of cats walking on snow.

Similar to the “we’re being sneaky so step where I step” trope you’ll see in books or movies, stepping in the same spot twice minimizes how much noise the cat makes when it moves.

Another anatomical adaptation is the cat's paws. If you have ever had the pleasure of touching the underside of your cat’s paw, you may notice that the little pads are very soft- very different from a hard, calloused dog paw. Not only is the skin soft, there is soft fur growing densely around the pads.

And here’s a dog paw for comparison.

Soft things like cat paws make less noise than hard things when they move, because soft things spread out upon impact, muffling sound.

You’ll also notice that the dog’s paw has the blunt nails extended, while cats can retract their claws. Not only does this keep them sharp, it also keeps them from making any noise.

Cats also make a lot less noise breathing when they move than other animals- you’ll notice a cat doesn’t pant like a dog when it walks or runs. (If you see your cat panting, that is a BAD sign. Call your vet.)

But essentially, cats are generally evolutionarily engineered quietude machines.

Now, as to your second question about dog mortality… the answer is a bit more complicated. So much so that I'm going to make a separate post for it tonight when I get home from work. Stay tuned!

Melanism (for those who don't know) is a phenotype where unusually high amounts of melanin are produced in the skin and sometimes body tissues. This can lead to solid black or very dark brown-looking animals.Solid black cats are affected by melanism.The genetics of this are a bit complicated, so bear with me a second. There are three genes we're going to be examining- the black gene, the agouti gene, and the tabby gene.

The black gene in cats (Bb) controls the concentration of eumelanin granules within the fur. However, in order for a cat to be solid black, the gene that codes for agouti (banded hair) must be suppressed. The recessive phenotype aa at this locus allows for individual hairs to be solid instead of banded.

(A- refers to the fact that the expression will be the same whether the genotype is AA or Aa.)

This gene is also epistatic to the tabby gene (Tt), meaning if the agouti gene is suppressed, the tabby gene will also not be visibly expressed. Tabby coloration is what produces stripes of differing darkness on cats- you can see that this cat has solid black stripes in some areas and agouti stripes in others. Its genotype should be something along the lines of A- B- T-.

Basically, if expression of agouti hair is blocked (genotype aa), it should also block expression of the striping regardless of what type of tabby gene your cat has because, obviously, the agouti stripes don't exist! This leaves a solid-colored cat, which would naturally be black or brown, depending on which dominant or recessive alleles it had in its black gene (Bb). Black cats have a genotype of aa B- with any tabby gene.

Interestingly the gene for orange hair actually overrides the non-agouti (aa) expression, so orange patches of fur on cats will ALWAYS have a tabby pattern.

...Okay. That's all a bit complicated and probably far more than you wanted to know. But as to your cat, her occasionally-visible striping is probably due to slight expression of the agouti gene. And the fact that her hair looks to be lighter brown in the sunlight? She could possibly be carrying the Siamese gene (cs) which actually causes fur to turn lighter-colored due to heat.

Her white blotches are controlled by yet another set of genes, the spotted gene (Ss) which has incomplete dominance and causes patches of fur to develop without pigment, hence the white color.

The really interesting thing, going back to wild cats, is that while melanism is common in a number of wild cat species, only three express melanism because of the same combination of genes that domestic cats do. Others are black due to mutations in completely different areas! This trait was clearly important enough to evolve at least four separate times within the cat lineage.

It's thought that melanism in cats may actually confer resistance to some diseases, which is why some populations of wild cats may have high concentrations of melanistic individuals after an epidemic.

All in all, it's fascinating stuff.

To puzzle more over cat coat genetics, try this page from Berkley and this page from the cat fancier's association.

Here's the study that discusses the separate evolution of melanism in the cat family- I unfortunately don't have access to a full text version.