Evolution and Adaptation

The theory of sexual selection was formulated by Darwin, even in the first edition of the “Origin of Species,” but was developed at much greater length in “The Descent of Man.”...

In the present chapter we may first consider, from the point of view of discontinuous variations as contrasted with the theory of the selection of individual variations, the str...

We come now to a consideration of other theories that have been advanced to account for the evolution of new forms; and in so far as these new forms are adapted to their environ...

One of the most striking and peculiar characteristics of living things is that through use a part is able to carry out a particular function better than before, and in some case...

Darwin’s theory of natural selection is preëminently a theory of adaptation. It appears, in fact, better suited to explain this phenomenon than that of the “origin of species.”...

Although in the preceding chapter a number of criticisms have been made of the special parts of the theory of natural selection, there still remain to be considered some further...

In what sense may the separation of all the individuals of a species into two kinds of individuals, male and female, be called an adaptation? Does any advantage result to the sp...

The two terms _continuous_ and _discontinuous variation_ refer to the succession or inheritance of the variations rather than to the actual conditions amongst a group of individ...

Of the different kinds of adaptation none are more remarkable than those connected with the immediate responses of organisms to external agents. These responses are usually thou...

At the close of the eighteenth, and more definitely at the beginning of the nineteenth, century a number of naturalists called attention to the remarkable resemblance between th...

Between an organism and its environment there takes place a constant interchange of energy and of material. This is, in general, also true for all bodies whether living or lifel...

One of the most important considerations in connection with the problem of adaptation is that in all animals and plants the individuals sooner or later perish and new generation...

The question of the origin of the adaptations with which the last three chapters have so largely dealt is one of the most difficult problems in the whole range of biology, and y...