If you believe in natural selection then you must believe there's an interplay between [at least] creatures, Nature, and choices. For 'selection' to be happening, either the creatures, Nature, or both must be doing the 'selection'.

So -

Who is making the selections?

In other words -

Who is making the choices?

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It isn’t about survival of the fittest.

It is about survival of the most adaptable.

Regardless, if you believe in being more fit or being more adaptable –

Who is making the choices?

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Is it about the creature’s willpower?

Is it about the power and forces of Nature?

Footnote – source: quoteinvestigator.com    

Megginson presented his own idiosyncratic interpretation of the central idea outlined in Darwin’s “On the Origin of Species”. 

Yes, change is the basic law of nature. But the changes wrought by the passage of time affects individuals and institutions in different ways. According to Darwin’s Origin of Species, it is not the most intellectual of the species that survives; it is not the strongest that survives; but the species that survives is the one that is able best to adapt and adjust to the changing environment in which it finds itself. Applying this theoretical concept to us as individuals, we can state that the civilization that is able to survive is the one that is able to adapt to the changing physical, social, political, moral, and spiritual environment in which it finds itself.