The one most responsive to change

Quoted in Natural Selection and the Origin of Economic Growth by Oded Galor and Omer Moav.

It is not the strongest of the species that survive, nor the most intelligent, but the one most responsive to change. - Charles Darwin

An excellent quote but it turns out to be a misattribution that arose in the past couple of decades. The original is of course:

In the struggle for survival, the fittest win out at the expense of their rivals because they succeed in adapting themselves best to their environment.

Which says essentially the same thing but the misattribution has a lilt to it that makes it more attractive. Probably because of the distant Ecclesiastical bell it rings (Ecclesiates 9:11):

The race is not to the swift, nor the battle to the strong, neither yet bread to the wise, nor yet riches to men of understanding, nor yet favor to men of skill; but time and chance happeneth to them all.