House cats often appear aloof and indifferent toward their human companions. But it's not just an act — they actually don't care. A recent study of the domestic cat genome reveals why.
Scientists from the Genome Institute at the Washington University School of Medicine in St. Louis sequenced the first house cat reference genome, and discovered that house cats may not be that genetically different from wild cats. This may explain why house cats seem to ignore their human companions and instead behave like they have their own agenda. Maybe they're acting like wild cats.
Generally house cats are quite adept at hunting, sharing many of the same genetic traits that make wild cats such effective predators. The genetic adaptations highlighted in the study indicate that house cats still retain many of the characteristics of wild cats, including acute vision, fast reflexes, and an innate desire for murder. Many of the behaviors house cats engage in are thought to be predator learning behaviors – pouncing, kicking with the hind limbs, and chasing prey (laser pointers) and can be seen in wild cats.
These behaviors emerge in house cats within the first 52 days of life before any prey is encountered. This supports evidence of a strong genetic link between house cats and wild cats. Even if given sufficient food, house cats will still pursue prey — though they won't eat it.
Some breeds of house cats are closer to their wild counterparts than others. Savannah cats are first generation crosses of domestic house cats with wild serval cats (medium sized wild cats indigenous to Africa).
Though house cats and wild cats have a lot in common, their genetic differences reveal how the domestication of house cats may have worked. Areas where the domestic cat's genome differs from wild cats are linked to adaptations in fear and memory/reward conditioning.
The changes in fear conditioning would make house cats more difficult to startle — though this doesn't explain the neurotic tendencies of many domestic house cats. Genetic changes in the memory/reward system would make it easier for house cats to quickly link rewards (like treats) with actions. House cats can, in theory, attribute rewards received to 'good' actions faster than their wild counterparts. During neonatal development, domestic house cats have higher numbers of the progenitor cells that form the cortical areas responsible for processing reward information. This leads to larger cortical areas that are responsible for processing reward information – fine tuning house cats' ability to hone in on what exactly led to the cat treat.
Cats retain more similarities to their wild counterparts than dogs do. The domestication process in cats more than likely started with increased docility, making it easier for cats to interact with humans. These changes would have been a result of 'self-domestication', where animals selectively breed to encourage or discourage traits.
Interestingly this is somewhat similar to early genetic modifications in dogs. Some of the first genetic changes in dogs were thought to involve reduced hostility and changes in social cognition. Evolutionarily speaking, cats may still be early in the domestication process — especially when compared to dogs. Over time, as the domestication process continues, it would not be unreasonable to expect cats to become more like dogs.
Read the full scientific study at PNAS