THE STRATEGY OF EVOLUTION.

There is an embarrassing lack of surprises in certain aspects of evolutionary theory. For example, if a bird has only seawater to drink, it is not surprising, given our knowledge of birds in general, that some mechanism must exist for eliminating salt if the bird is to survive. It is not possible to state a priori what the mechanism is for any particular bird. It is therefore intellectually pleasing that gulls excrete strong brine through a nasal gland (Schmidt-Nielsen, 1960). The novelty of the arrangement provides the same kind of intellectual satisfaction in the twentieth century that I imagine the information in the Bridgewater treatises provided in the nineteenth (Whewell, 1833), or Henderson’s Fitness of the Environment (1913) to the teachers of our teachers. Nevertheless, physiological and even behavioral adaptations, no matter how apt, seem only what ought to be expected from our knowledge of natural selection, survival of the fittest, and other catch words.