Could the silver trout be bred back into existance

After reading the article on how a landslide damming a lake caused interbreeding of different strains in rainbow trout who breed normally at different seasons, I got thinking on trout subspecies interbreeding.

The silver trout (savelinus fontinalus agasizzi) if the info mentioned here on them being a subspecies is correct. (species vs subspecies in trout tends to depend on what article you read) spawned in streams containing normal strain brook trout. The spawning timing difference was only about two weeks if what I read was right.

Could interbreeding have happened? If so does that mean the genes of the extinct silver subspecies could still exist in the brook trout population waiting to be reassembled through selective breeding?

The silver trout had only been geographically cut off since the glaciers retreated after last ice age. Eight thousand years is not a very long time, not long enough for it to become really different. Its genes already do for the most part exist in the surviving strain of trout that wasn't limited to three lakes, even without an interbreeding event occurring. I'm not sure what your goal would be in backbreeding, though. Trout don't make very good pets, and there are cheaper ways to make food fish.

Ancestral species can differentiate in under 10,000 years, with the pupfishes of the southwest being a classic example. But a lot of that differentiation isn't through new alleles or chromosomal arrangements necessarily, much of the difference can be in plasticity of phenotypic response to the environment accomplished through slight variation in genetic expression. In principle you could probably recreate a fish pretty similar to the silver trout, but it wouldn't be the same organism just very similar.

The silver trout had only been geographically cut off since the glaciers retreated after last ice age. Eight thousand years is not a very long time, not long enough for it to become really different. Its genes already do for the most part exist in the surviving strain of trout that wasn't limited to three lakes, even without an interbreeding event occurring. I'm not sure what your goal would be in backbreeding, though. Trout don't make very good pets, and there are cheaper ways to make food fish.

I had a chat with some of my fellow Ph.D. students who are smarter than I am, and they corrected me that 8,000 years is a long time for a fish whose generation time is like six years. They agree with me that the exon coding portions are mostly are the same in the surviving trout, but they think the intron, regulatory regions might be very very different. I guess those regulatory regions can change pretty quickly.
They agree that backbreeding would yield a similar but not identical fish to the silver trout.

http://www.time.com/...1961918,00.html This is pertaining to extinct bovines, but you may find it interesting.