If a little knowledge is dangerous, where is the man who has so much as to be out of danger?
Thomas H. Huxley

It is an error to imagine that evolution signifies a constant tendency to increased perfection. That process undoubtedly involves a constant remodeling of the organism in adaption to new conditions; but it depends on the nature of those conditions whether the directions of the modification effected shall be upward or downward.
Thomas H. Huxley