Culture is not static. Yes, the clan rituals of all the mammoth families from 4,000 years ago are forgotten forever, but most, if not all, of it would have been

Culture is not static. Yes, the clan rituals of all the mammoth families from 4,000 years ago are forgotten forever, but most, if not all, of it would have been lost by now anyways. Instead, new cultures develop and will develop if we release cloned mammoths in the arctic. It will take generations to return to a natural like state, but it could get there. As for salmon, yes, the farmed salmon does not remember the stream it spawned. Nevertheless, you can take the progeny of those salmon and relocate them to a river that has been renaturalized, like it is happening in many places in Europe. Sure, the salmon will not be the same, but once the bears recognize it as a food source again, they will play the same role in the ecosystem as their distant relatives once did.