Founder effect in the creation of a cat breed

In terms of community and domestic cats, the so-called "founder effect" is apparent in, for example, two cat breeds that come to my mind quite quickly namely the Manx and the Turkish Van. There are others. Both these breeds were moggies at one time living in the communities from where they orginate.

Manx cat was created via the founder effect on the Isle of Man many years ago.
Photo copyright Helmi Flick.

In relation to domestic cat evolution, the founder effect works when a population of domestic and community cats are in a certain area and confined to that area. Some early members of this group of cats become the foundation cats for all the cats in the area. It's a bit like the creation of a breeding line when cat breeders selectively breed for a certain appearance. They choose a foundation cat and use that individual throughout their entire breeding programme and indeed other breeding programs. There is a loss of genetic variation.

The meaning of “lines” in cat breeding

Manx

This sort of thing can can occur naturally in a confined space. For example, the Manx cat was confined to the Isle of Man which is about 30 miles long. A genetic mutation for a missing or short tail occurred in one cat on that island. It was passed through inheritance to other cats. The original mutated domestic cat with a short tail became a foundation cat to all others until there was a large population of short-tailed or no-tailed cats confined to a 30 mile long and 10 mile wide island.

Turkish Van

Turkish Van. Photo: Helmi Flick

The Turkish Van was created in an isolated population in the north-eastern mountains of Turkey  - the Lake Van region. Their appearance was perpetuated by their "founder" characteristic of orange-and-dominant white. Particularly, there is an inverted 'V' on the forehead between the ears, and the tail is coloured while the rest of the body is all-white. The appearance of the early foundation cats had a powerful influence over resulting generations of cats in that area.

The Real Turkish Angora

Polydactylism

The founder effect is why short tails were perpetuated in the isolated populations on the Isle of Man, as mentioned, and in Japan and the Kuril Islands (Kurilian Bobtail). And the founder effect also accounts for the high percentage of domestic and community cats in Boston with extra toes known as polydactylism. The original cats with extra toes procreated to create more and the genetic mutation did not dissipate among the general population but was confined to the Boston area. This allowed for a quite high percentage of cats with extra toes to be present in that area.

Why are Maine Coons polydactyl?

Bengal cat

All Bengal cats orginate in very few first generation leopard cat x domestic cat hybrids created in the 1970s as I recall.

Breed personality

You can find certain personality characteristics within cats of a certain breed because one male individual founder cat has passed on their inherited character to many cats within that breed because an individual founder cat was used by a number of breeders. Perhaps, this is why the Ragdoll cat is known to be laid-back. I don't know how many foundation cats in total exist for the Ragdoll cat breed but I suspect it is a very few and there may be one individual cat which started off that breeding line for all the cats of that breed which means their personality has been handed down for generations.