Page 134 - The Errors the American National Academy of Sciences

The Errors of the American National Academy of Sciences

that as they developed embryos passed through the adult forms of their
ancestors and "recapitulated" their evolutionary history. In other words,
he proposed that as already evolved features emerged at the end of de-
velopment, ancestral features could be observed in the early stages of that
development. Haeckel called this so-called theory of "recapitulation" the

"biogenetic law," and summed it up in the famous phrase "ontogeny reca-
pitulates phylogeny." In his The Descent of Man, Darwin portrayed
Haeckel's drawings as important evidence in support of his own theory.
Haeckel reached this conclusion not as the result of observation,
but by taking the theory of evolution as his starting point. In 1909, the
British zoologist Adam Sedgwick said this of Haeckel's theory:
The recapitulation theory originated as a deduction from the evolu-
tion theory and as a deduction it still remains. 2

The invalidity of the theory of recapitulation was soon realized. At
the beginning of the twentieth century many scientists had seen that it
was incorrect. Stephen Jay Gould wrote:
Haeckel's program of using the biogenetic law to search for entire an-
cestors in the embryonic stages of modern forms was pursued with
much hope and fanfare, but led to few positive results and endless
wranglings about untestable phylogenetic scenarios – all because the
phylogenetic law is basically false. By the closing years of the nineteenth
century, Haeckel's program had become a source of much ridicule… 3

In an article published in American Scientist in 1988, Professor K.S.
Thomson says:
Surely the biogenetic law is as dead as a doornail. It was finally exor-
cised from biology text books in the fifties. As a topic of serious theo-
retical inquiry it was extinct in the twenties. 4
Molecular biologist C. McGowan's admission was particularly
frank:

Like so many ideas, [recapitulation] seemed like a good one at the

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