What may survive.
Rather than seeing Man as the end of the evolutionary process, Stephen Jay Gould regarded all species as expressions of DNA. That may survive, and Man's contribution may be to see that DNA is distributed in order to express itself if it finds a "garden".
He used the example of a lion chasing an antelope. If the lion catches it, lion DNA wins. If it gets away, antelope DNA wins. Under this view no species is particularly important except to itself.
And that could well be true for Man and his derivatives. In the grand scheme it may be that the best we can do to survive is send out some generic DNA which has an easy time forming primitive life and wait for evolution. Maybe again.
Arf