The alternative to extinction is stagnation, and stagnation is seldom a good thing.

Perhaps we will one day be able at least to admit of a God possessing sufficient majesty and expansiveness to transcend the limits of our own imaginations and experience. But meanwhile, . . . we might do well to look upon the inadequacy of our concepts of God as the truest mirror of those limitations that define our condition.

When environments change, they usually do so pretty rapidly, at rates with which adaptation by natural selection would be hard put to keep up. When such change occurs, the quality of your adaptation to your old habitat is irrelevant, and any competitive advantage you might have had may be eliminated at a stroke.