Among American contributions to vertebrate palaeontology, 'the development of Cope's theories is to be found in the volumes of his collected essays, The Origin of the Fittest (New York, 1887), and The Primary Factors of Organic Evolution (Chicago, 1896).
If he is to be believed, at the bottom of all organic evolution organic impulses becoming habits produce structural changes, which are transmitted by heredity; and as an impulse thus gradually becomes secondarily automatic, the will passes to higher activities, which in their turn become secondarily automatic, and so on.
In Der Kampf urns Dasein am Himmel von Prel endeavoured to apply the Darwinian doctrine of organic evolution not only to the sphere of consciousness but also even more widely as the philosophical principle of the world.
Thus not only did Darwin's theory give a new basis to the study of organic 'structure, but, whilst rendering the general theory of organic evolution equally acceptable and Effects of necessary, it explained the existence of low and simple forms of life as survivals of the earliest ancestry of theory more highly complex forms, and revealed the classifications of the systematist as unconscious attempts to construct the genealogical tree or pedigree of plants and animals.
Lishing the doctrine of organic evolution by the introduction into the web of the zoological and botanical sciences of a new science.
The delay in the establishment of the doctrine of organic evolution was due, not to the ignorant and unobservant, but to the leaders of zoological and botanical science.
Aristotle's teleological conception of organic evolution often approaches modern mechanical conceptions.
It was reserved for Charles Darwin, in the year 1859, to place the whole theory of organic evolution on a new footing, and by his discovery of a mechanical cause actually existing and demonstrable by which organic evolution doctrine must be brought about, entirely to change the attitude in regard to it of even the most rigid exponents of the scientific method.
Von Baer thus prepared the way for Herbert Spencer's generalization of the law of organic evolution as the law of all evolution.