Question

The tadpole larva of amphibians resembles fishes. How does this observation support evolution?

Answer 1

Haeckel's hypothesis, “Ontogeny recapitulates phylogeny”, is frequently referred to as the recapitulation theory. Ontogeny refers to an organism’s growth and development, while phylogeny describes a species’ evolutionary history. According to Haeckel, higher species develop through stages similar to more basic species. The similarity between amphibian tadpole larvae and fishes suggests that amphibians evolved from fishes. For example, cold-blooded animals use gills for respiration and lay eggs in water. Amphibians evolved from fishes and adapted to terrestrial habitats. This adaptation resulted in the development of lungs and a three-chambered heart. Amphibians developed from fishes.