A la "transHumanism": The idea that if we could rewrite the plant genome, much better plants could be created.
Plant's energy cycle has built-in inefficiency. There are leaps of design that evolution can never take. But, if someone rewrote their chemical cycles in a lab, you could make plants that used their energy more efficiently, to grow twice as fast as any natural plant. The first variety like this would take over the world first, and then evolve to dominate each environment.
Lots of SF involves biological spaceships, planes, or more complete adaptation. Is it really possible? Making animals use propellors, or jets. Underwater creatures already do have some jets - squid, etc.
One problem with evolution here is that it has such a hard time not being hierearchical - you can't move innovations across species easily. Some meta-species organizations can sometimes evolve symbiosis, but it's complicated because both sides might always start cheating, and it could evolve into parasitism. Although that would satisfy my purposes, too.