Ernst Haeckel formulated his biogenetic law, famously stating that ontogeny recapitulates phylogeny, in 1872. The Russian evolutionist Alexei Sewertzoff, and the Swiss-born zoologist Adolf Naef were among those who revised Haeckel’s law, thus changing the course of evolutionary theory and of developmental biology. Although Sewertzoff and Naef approached the problem in a similar way and formulated similar hypotheses at a purely descriptive level, their theoretical viewpoints were crucially different. While Sewertzoff laid the foundations for a Darwinian evolutionary morphology and is (...) regarded as a forerunner of the modern synthesis, Naef was one of the most important figures in “idealistic morphology”, which is usually seen as a type of anti-Darwinism. Both Naef and Sewertzoff aimed to revise Haeckel’s biogenetic law and came to comparable conclusions at the empirical level. This paper is an attempt to explain how their fundamentally different theoretical backgrounds influenced their views on the relationship between ontogeny and phylogeny. (shrink)

This essay analyzes the view of evolution of Jan Lever (1922–2010), founder of the biology department at the Vrije Universiteit Amsterdam, and compares his view with those of J.H. Diemer and H. Dooyeweerd. Together with Dooyeweerd, Lever wrote a series of chapters on the species concept inPhilosophia Reformata(1948–1950) in which species were defined as constant types. In his book,Creatie en Evolutie(1956), Lever still subscribed to Dooyeweerd’s philosophy but also suggested that it is possible that biological evolution occurred, including that of (...) human beings, and that scientific research can shed light on these processes. Influenced by his idea of individuality structures, Dooyeweerd criticized Lever and suggested that species are constant; that science cannot speak to the topics that Lever discusses. It is argued that Dooyeweerd’s views are influenced by the typological thinking of the time and that reformational thought would benefit from de-emphasizing this aspect of reformational philosophy. (shrink)