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.

From a speech delivered in 1963 by a Louisiana State University business professor Leon C. Megginson at the convention of the Southwestern Social Science Association. The text of his address was published in the quarterly journal of the association. — https://quoteinvestigator.com/2014/05/04/adapt/

The quote above cites Darwin as the source of the phrase in bold.

Darwin never said it. https://www.darwinproject.ac.uk/people/about-darwin/six-things-darwin-never-said