Biology Question on evolution and natural selection

Question

Biogenetic law was given by

Answer 1

Solution

In $1828$ , Von Baer, the father of modem embryology, proposed Baer's law which stated that during embryonic development, the generalised features (such as brain, spinal cord, axial skeleton, aortic arches, etc. are common to all vertebrates) appeared earlier than the special features (like hair in mammals only, feathers in birds only, limbs found in quadrupeds only) which distinguish the various members of the group. Later on this law was modified as the biogenetic law or recapitulation theory by Ernst Haeckel in $1866$ . Haeckel's biogenetic law states that "Ontogeny repeats phylogeny". Ontogeny is the life history of an organism while phylogeny is the evolutionary history during its development.