Ontogeny and Phylogeny Despite the fact that the 'law of biogenesis' (ontogeny recapitul

 Ontogeny and Phylogeny 
     Despite the fact that the "law of biogenesis" (ontogeny 
recapitulates phylogeny) was discredited early in this century, one 
still reads or hears references to its putative truth, and thus 
articles such as the following are still necessary. Take a look at 
"Human embryology and the law of biogenesis," by  Gunter Rager  
(Institute of Anatomy, Fribourg, Switzerland), in  Rivista di 
Biologia-Biology Forum  79 (4), 1986, pp. 449-459. Rager writes:

The law of biogenesis was introduced using faked material. Apart 
from that it suffers from a number of inconsistencies. There are 
many data which do not fit. The explanatory power of this law is 
poor because it is not able to make predictions for ontogenetic 
mechanisms and processes. Haeckel's assertion that the law of 
biogenesis is the only possible explanation for similarities in 
the development of different species can no longer be held 
upright because an alternative view is possible...With the 
improvement of our scientific tools we can state that ontogeny is 
much better known than phylogeny, conditions and causes for 
differentiation and maturation can be found in ontogeny only, and 
phylogeny is based on ontogeny. Finally we have seen that despite
of many similarities with other species human development is
always specifically human. (p. 459)