Country: United States
Date: May 2006
I was watching a show on
wolf/dog evolution and a
point was made that the dog genetics contain much variability -
implying that dogs carry many unexpressed genes which can be
expressed by controlled breeding.
So I got to wondering - does a chihuahua, say, actually carry
-unexpressed- the gene for a great dane or its parent wolf? More
importantly, if this is true, could we turn a chihuahua back to a
wolf with selective breeding? And most interestingly, could we -over
the course of many generations- ultimately breed for dog/wolf
ancestors that are already extinct?
No doubt they have unexpressed genes...also, in outbreeding you would see at
least some of the "ancestral" body shape reapear. Recall that there is very
little genetic difference between all dogs since they can
interbreed...including with the wolf...in my opinion, by definition the
common domestic dog should be classified as the same species as the
wolf...because they can readily interbreed. As far as resurecting extinct
ancestors from extant species....it seems unlikely...but when it come to
genetics, I am never surprised at what seemed once impossible is now fact.
All breeds of dogs were derived from wolves as a result of mutation of wolf
genes and selective breeding by man. These mutations were not carried by the
ancestral wolf but arose during the 15,000 years they have been under
domestication by man. Theoretically, it would be possible to evolve a
wolf-like dog from Chiuauas, but it would take thousands of generations
waiting for the right mutations to occur. The resulting "wolf" would look
like a wolf but would not be genetically identical to wolves.
Ron Baker, Ph.D.
You couldn't turn an individual dog into another kind. Individuals don't
evolve. But if you kept selectively breeding one dog to another, after many
generations its descendants would begin to look different over time. You
would also have to breed many individuals and have many many offspring
because you couldn't always be sure of what traits the offspring are going
to express. There is no guarantee that you could back cross to the original
A very interesting question. While I am not a geneticist, my understanding
is that yes, with enough generationg - and it might be a great many -some
breeds of dog could be derived from others. I don't know if a specific breed
could be recreated. The question of breeding back to extinct ancestors has
been brought up in theory and I believe has been attempted with some
This site has an article about breeding the extinct quagga from zebras.
Click here to return to the Molecular Biology Archives
Update: June 2012