Claim CB701.1:
The biogenetic law that ontogeny recapitulates phylogeny (that is, that
the embryological stages of a developing organism follow the organism's
evolutionary history) is false, yet embryological stages are still claimed
as evidence for evolution.
Source:
Morris, Henry M., 1974. Scientific Creationism, Green Forest, AR: Master
Books, 76-77.
Response:
- Haeckel's biogenetic law was never part of Darwin's theory and was
challenged even in his own lifetime. Haeckel himself did not
necessarily advocate the strict form of recapitulation commonly
attributed to him (Richardson and Keuck 2002).
- Irrespective of biogenetic law, embryological characters are still
useful as evidence for evolution (in constructing phylogenies, for
example), just as adult characters are. Furthermore, there is some
degree of parallelism between ontogeny and phylogeny, especially when
applied only to individual characters (Richardson and Keuck 2002).
Various causes for this have been proposed. For example, there is
selective pressure to retain embryonic structures that are needed for
the development of other organs.
Links:
Chase, Scott, 1999. Is Haeckel's law of recapitulation a problem?
http://www.talkorigins.org/origins/postmonth/feb99.html
Wilkins, John, 1996. Darwin's precursors and influences: 1.
transmutationism.
http://www.talkorigins.org/faqs/precursors/precurstrans.html
References:
- Richardson, M. K. and G. Keuck, 2002. (see below)
Further Reading:
Gould, Stephen J., 1977. Ontogeny and Phylogeny. Cambridge, MA:
Belknap Press.
Richardson, M. K. and G. Keuck, 2002. Haeckel's ABC of evolution and
deveolopment. Biol. Rev. 77: 495-528.
created 2003-7-23
