Why are cat breeds roughly the same size but dog breeds vary so much?
Speaking only about domesticated animals...I know there are subtle differences between cat breeds but for a non animal lover, various dog breeds are obviously different sizes and shapes. Even without any knowledge of dogs a rottweiler is clearly different than a teacup chihuahua. With cats, they are all roughly the same size so unless you really know cats they all look the same. Why did these animals develop this way?
Public Comments
1. Dogs have come from centuries of selective breeding because they were needed far more than a cat, thus a cat has no need to have been bred in different sizes. Dogs were made larger if they were to hunt lions (rhodesian ridgeback) and smaller if they were to hunt rabbits (beagle)2. Cats are normally about the same size (at least the ones you can domesticate) Dogs vary very differently from cats. It's all in the DNA. Cat's main differences in breeds are personalities and fur, but some breeds are taller than others. There is one breed of cats which has really short legs. It's called Munchkin. Yes there actually is a breed of cat called Munchkin, laugh if you want. But ya, cats and dogs are very different animals.
3. It is because humans have manipulated dog's genes to produce traits that we exploit. Cats are not as adaptable to our whims.
4. Kyle is right -- dogs have been, over the course of thousands of years, selectively bred for a great variety of jobs
Cats have also been domesticated for thousands of years but they've had one important job that they specialized in -- rodent control. They are incredible hunters but less easy to train, so early humans weren't as motivated to breed them for hunting other types of game.
Cats are in some ways more like a wild species; there has been far less selective breeding of cats than of dogs. The vast majority of cats have just bred randomly on their own. The breeds have come from random-bred populations and while there's been selective breeding that has changed some of them, most controlled cat breeding is actually a relatively modern practice that started in the 19th century. A few cat breeds have been bred for centuries but there just has not been any impetus to greatly change their size
5. Because basically cats are mouse/rat hunters and don't need to do anything else and so size is not important. Dogs have a wide range of "jobs" and so developed differently to be used in those jobs. You have terriers that are cat size to hunt rats and you have larger breeds to hunt with in the field or guard property/sheep, etc.
