Question

Haeckel’s recapitulation theory/biogenetic law states
A) Ontogeny repeats phylogeny
B) High rate of reproduction
C) Alternation of generations
D) Inheritance of acquired characters

Answer 1

The theory of recapitulation or biogenetic law provides a hypothesis that the different stages of development of an embryo represents adult stages of evolution of their ancestors. The development stages of the embryo are referred to as ontogeny whereas the stages of evolution of its ancestors is termed phylogeny.

Complete answer:
Ernst Haeckel was a German scientist who had a great contribution in the field of biology. He has coined several of the important biological terms that are used even today. Some of them being ‘ecology’, ‘phylum’, ‘phylogeny’. The theory of recapitulation was proposed by Ernst Haeckel in the nineteenth century which is majorly based on the Lamarckian principles. The theory was formulated as “ontogeny recapitulates phylogeny”; where ontogeny is the development of an organism and phylogeny stands for its evolutionary history. Haeckel gave many examples to prove his theory such as- pharyngeal arches present in the neck of the human embryo resembled gill slits of fishes. He also provided many embryo drawings that showed similarity between embryos of related species.

So the correct answer is (A) ontogeny repeats phylogeny.

Note: Though his theory was widely criticized and was rejected but it formed the first framework of developing modern evolutionary biology that helps us to get a very detailed knowledge of the developmental stages of embryos. This helps us to get an idea about the range of changes that the embryo undergoes to finally form the adult organism.