Question

The presence of gills slits, in the embryos of all vertebrates supports the theory of
(A)Metamorphosis
(B)Biogenesis
(C)Organic evolution
(D)Recapitulation

Answer 1

Hint The presence of gills slits in the embryos of all vertebrates is a theory of development and evolution proposed by Ernst Haeckel in Germany in the 1860s.This theory is also known as the biogenetic law.

Complete solution: Complete step by step solution: The theory of recapitulation, which is also commonly known as the biogenetic law or embryological parallelism is often expressed by using the very popular phrase of Ernst Haeckel's "ontogeny recapitulates phylogeny".It's considered to be a historical hypothesis which states that the development of the embryo of an animal, ranging from the method of fertilization thereto of the gestation, goes through the many different stages and that stages resemble or represent the successive adult stages within the evolution of the animal's remote ancestors (phylogeny). it had been formulated within the year the 1820s by Étienne Serres, who supported the work of Johann Friedrich Meckel, after whom it is also mentioned as Meckel–Serres law.

Additional Information: The basic idea of this recapitulation was first formulated in the field of biology from the year the 1790s onwards by the German natural philosophers Johann Friedrich Meckel and Carl Friedrich Kielmeyer, and even by the Étienne Serres. He is the one after whom, Marcel Danesi states, it soon gained the status of a supposed biogenetic law.
The embryological theory was formalized by Serres in 1824–26, supported by Meckel's work, in what became referred to as the "Meckel-Serres Law". This attempted to link comparative embryology with a "pattern of unification" within the organic world. it had been supported by Étienne Geoffroy Saint-Hilaire, and had become a prominent part of his ideas. It suggested that past transformations of life could be through environmental causes performing on the embryo, instead of on the adult as in Lamarckism. These naturalistic ideas led to disagreements with Cuvier. This very known idea was widely supported within the London schools of higher anatomy around the year 1830 but was opposed by Karl Ernst von Baer's ideas of divergence, and attacked by Richard Owen within the 1830s.

So, the correct answer is ‘Recapitulation’.

Note: The Haeckelian kind of recapitulation theory is considered no longer in effect. It was considered that the Embryos will undergo a period of the phylotypic stage in which they found to be morphologically strongly shaped because of their phylogenetic position, instead of selective pressures, but meaning only that they will be resembling the other embryos at that stage, not ancestral adults as Haeckel had claimed.