Biogenetic law

Biogenetic law (from the Greek. bios - life, genesis - the origin, development) is a logical relationship between the individual development of an organism (ontogeny) and its development during the evolutionary process (phylogeny). First considerations on the passage of the higher animals stages, relevant organizations lower, expressed Meckel (J. Meckel) in the early 19th century. K. M. REM claimed (1828)that the germs of the highest forms of the kind adults lower animals, but their fetuses, and showed the sequence of signs during embryonic development: first, develop signs of type, then class, genus, species (law Baer). H. Darwin believed that the embryos and larvae of many animals indicate the structure of their ancestors in adulthood. In 1866 Haeckel (E. Haeckel) has formulated the "main biogenetic law": the embryonic development of this form there is a recap of phylogenetic development. Touching on human embryonic development, Haeckel stated that egg cell corresponds to a primitive organism, gastrula stage is similar to coelenterates, later - with worm-like animals; next, in embryo, human appear Gill slits and arc characteristic of fish. Haeckel was the step palingenesis - embryonic recurrence of signs that are inherited from a distant ancestors (for example, Gill slits embryo of the person), and cenogenesis - signs, emerging as an adaptation to fetal life (for example, the amnion, allantois, chorion germ of higher vertebrates and human).
Further accumulated facts that contradicted the basic biogenetic law, and embryologists ceased to search for the cause of development in previous history of the species. Evolutionary course in embryology received a new development in the works of A. N. Russian Academy of science, who developed the theory of firebrigades, i.e. the theory of evolution through changes in individual development, which became possible to analyze the way there are indications of adult animals.
Cm. also Ontogenesis, Phylogenesis, Evolutionary doctrine.