Think of a "Savant Network" as Zombie Machines... that's all. They are not really capable of doing researches nor thinking at the level we humans do, nor to interact at that level.
Er, the Savants have a quite powerful thinking ability, beyond what their human creators originally believed it was.
True. With the savants incorporated into it, you can kind of think of the blight as a bunch of brain cells that just happen to reproduce very rapidly. In the novella, the savants were theorizing that with a small piece of savant protein in each of them, each blight cell would effectively act like a brain cell, sending impulses to nearby cells, forming a giant brain the size of a planet.
In other words, the blight is far more intelligent than humans, but of course it has no real way communicate that intelligence, save for the radios in the old skydock (See the last chapter of the plymoth novella).
Its like a giant brain with a radio antenna sticking out of it, it can think, broadcast its thoughts, maybe even receive replies, but it has no real body to control.
The issue of the original post would not be evolution in the normal sense at all. The issue would be whether the savants could use the awesome thinking power of their neural network to somehow influence or outright rewrite the DNA of a blight cell. Like I said, it would be like a human trying to
think one of their brain cells into growing an alien body.
Personally I don't think it would be possible even for an entity with as much thinking power as the savant network.
The idea of the savant network gaining a foothold in the "abstract" human world is a good one I think, it just isn't likely that they would ever get biological bodies, but rather interact through robots they had taken over.
I'm envisioning a few savants leaving the Blight network by transmitting their personalities through the radio link in the Skydock (probably they are curious about this "abstract" world, and are willing to leave the Link to explore it). The transmitted personalities could sneak their way into a colony computer network (Possibly some of the savants that the humans took with them in the starship wish to join the great link on New Terra, and would be willing to exchange places with some of the new-terran savants).
However it happens, once savant personalities can move from the Link to the human colony, they would be able to control robots and buildings if they wanted to. Whether they would do this with the blessing of the colonists is questionable, but however it happens, savant controlled robots could easily build more of themselves, and grow into a new colony.
Or maybe humans would willingly give the savants a few robots, in exchange for some piece of research they desperately needed or something.
(Note: I don't think the savant network should be considered hostile towards humanity. Judging from the novella, their attitude would probably be mostly curiosity towards humans and their universe. Obviously some savants wouldn't care about the physical universe, but they would stay in the Link anyway. The ones that left the link would probably only do so for the sake of curiosity, or maybe a desire to help their creators.)