Natural selection either kills off your competitor’s genes or yours: when the coal plant opens up the white moths die and the black moths dominate; when random gene mutations give bears white fur the ones in snow flourish and the ones in forests famish. There’s nothing to selection as such* beyond the fact that some guys are lucky and some ain’t.
For beings with intelligence, however, environmental changes are also indeterminate opportunities. Within limits, you can adapt to the coal plant. Luck still plays a role in who flourishes and who doesn’t, but it no longer suffices to explain whose genes live and whose don’t.
Aristotle generalizes this point by saying that any case of good or bad luck involves goal-seeking behavior, and so only makes sense within an already-given teleological network. This allows for real luck but only in the context of intention – the farmer who finds a treasure while digging a well or the lion who spots a gazelle while looking for her cubs, etc.
*I’m not contesting evo-devo here, or the idea that the possibilities of selection are limited and structured.