In addition to the two forms of the theory above noted, Haeckel added emphasis to these so-called biological proofs by putting forth a doctrine that came [p 18] to be called the biogenetic “law,” even though it was nothing but a hypothesis. It was called the recapitulation theory, because it was imagined that the developing human embryo recapitulates or passes through successive stages of the more mature forms of some of the lower animals.
Concerning this theory Dr. A. Weber, University of Geneva, Switzerland, said in the “Scientific American Monthly” for February, 1921: The critical comments of such men as O. Hertwig, Kiebel, and Vialleton, indeed, have practically torn to shreds the aforesaid fundamental biogenetic law. Its almost universal abandonment has left considerably at a loss those investigators who sought in the structures of organisms the key to their remote origins or to their relationships.
So it would seem that if this form of the theory is utterly destitute of proof, the whole biological foundation of the theory is gone.
It is perfectly in harmony with scientific testimony, therefore, that Professor Price says concerning this phase of the theory: The science of twenty or thirty years ago was in high glee at the thought of having almost proved the theory of biological evolution. Today, for every careful, candid inquirer, these hopes are crushed; and with weary, reluctant sadness does modern biology now confess that the Church has probably been right all the time.
If these men have borne faithful testimony to the situation as it now exists in the biological realm, the only conclusion possible is that the borrowed portion of Darwin’s theory has also utterly collapsed.
[p 19] It is passing strange, in view of these facts, that competent and scholarly men of science should still cling to a theory so utterly discredited by eminent scientists. Is it because they are determined to believe in evolution in spite of such evidence to the contrary, or is it because there is still left a foundation for the doctrine lying back of all this which has not yet been disturbed, even though “the biological clues have all run out,” as Professor Price says they have?
The supposed evidence of geology, with its theories of uniformity and successive ages, forms precisely such a foundation.
b. We will consider, therefore, in the next place, the so-called proofs taken from the geological realm.
Dr. T. H. Morgan, who was quoted above as against the theory of the inheritance of acquired characters, rests his faith in the theory of evolution on a geological foundation. He says: The direct evidence furnished by fossil remains is by all odds the strongest evidence we have in favor of organic evolution.