[js1138]

How is it that domesticated dogs of nearly all breeds will revert back to a single form in a relatively short period of time when released into the wild?

One of the first things that will happen to a truckload of domestic dogs released into the wild is that most of them will die, particularly the miniatures and toys. The ones closest to wild dogs will be the most likely to survive and breed.

There is nothing inconsistent with domestic animals being the result of both selective breeding and mutation.

[inquest]

The ones closest to wild dogs will be the most likely to survive and breed.

But their descendants will continue to revert, will they not?

There is nothing inconsistent with domestic animals being the result of both selective breeding and mutation.

I didn't say there was. What I was wondering was whether the changes that happen on a timescale necessary to introduce new breeds can realistically come about entirely through mutations, or if they necessarily come about mostly through other factors that might alter the genotype.