348 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1958 
mechanism for generating an exceedingly high degree of 
improbability.” 
Mention of purpose introduces the notion of teleology or fulfill- 
ment of design which has sometimes been invoked to explain the pro- 
duction of complex adaptations. Teleology and providential guid- 
ance are double-edged weapons with which to attack the problem of 
evolution, because it can be shown that the more detailed the adapta- 
tion, the more “improbable” it may appear as a product of “chance,” 
the more likely its possessor is to be doomed to extinction through in- 
ability to become adapted to changed conditions. 
Structures may be developed which at first benefit individuals in 
their competition to survive; but by continued selection such struc- 
tures may become exaggerated and lead to the extinction of the spe- 
cies. This seems to have been what happened to the huia bird, where 
mated pairs constantly remained in company together, and the beaks 
of the male and female reached an extraordinary disparity of size 
in adaptation to their very special feeding, but failed to enable the 
birds to obtain ordinary food when their special diet was unavailable. 
Excess, even of adaptation, is harmful, and the fossil record shows 
that the vast majority of lines of evolution have led to extinction. 
From the undoubted fact that many of the products of the plant 
and animal kingdom convey to man the aesthetic quality of beauty, it 
has been supposed that beauty is an end in itself to which the criterion 
of usefulness and survival value could not be applied, and therefore 
that it could not be imagined as a product of evolution. To this argu- 
ment Wallace opposed the demonstration that if the quality of beauty 
were an exception to the principle of evolution by natural selection, it 
would be necessary to find an explanation for the existence of so 
much in plants and animals that is positively ugly. 
Darwin showed it to be an invariable rule that “When a flower is 
fertilised by the wind it never has a gaily-coloured corolla.” The 
beauty of flowers has been gradually achieved because of the survival 
value of cross fertilization (consequent upon the attraction of in- 
sects to such flowers) conferred on plants possessing them. The beau- 
tiful colors and structures of birds and some other animals have re- 
sulted from the survival value conferred on successful competitors 
in sexual selection. 
This demonstration of what may be called the natural nature of 
beauty has been developed still further by Ray Lankester in the course 
of a soliloquy on alpine flowers: “All beauty of living things, it seems, 
is due to Nature’s selection, and not only all beauty of color and form, 
but that beauty of behavior and excellence of inner quality which 
we call ‘goodness.’ The fittest, that which has survived and will sur- 
vive in the struggle of organic growth, is (we see it in these flowers) , in 
