survival value

Its survival is a matter of absolute certainty, because of its survival-value.

A chief fact of progress has been, in a word, the supersession of the quantitative by the qualitative criterion of survival-value.

If mankind lost this capacity, all its other characters of survival-value, such as intelligence, would obviously avail it nought.

He may have been a throw-back to ancestors who had known bravery, which had no survival-value here.