Presence of gills in the tadpole of frog indicates that `:`

Options

A. fishes were amphibian in the past
B. fishes evolved from frog-like ancestors
C. frogs will have gills in future
D. frogs evolved from gilled ancestors

Answer

D

Explanation

According to biogenetic law of Ernst Haeckel (1866) ontogeny repeats phylogeny. Ontogeny is the life history of an organism while, phylogeny is the evolutionary history of the race of that organism. In other words we can say an organism repeats its ancestral history during its development.
Hence, resemblance of amphibian to fish is seen in most systems of the body as both are cold blooded, both respire by gills (as tadpole of frog), both usually lay eggs in water leading to the conclusion that amphibians have originated from fishes.