Fortunately evolving into "energy beings" as in Star Trek and 2001: A Space Odyssey is an extremely stupid idea. And it has nothing to do with natural selection. Science fiction, including "hard" SF such as Ben Bova, usually rejects Darwin. Life comes about merely because there is a space for it to fill. That is, for a "final cause" (Aristotle's "telos"). Science fiction writers are unwitting contributors to measles misinformation.
Natural selection is easy to understand.