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III. Convergent evolution is development of similar adaptive functional structures in
unrelated groups of organisms. Examples are:
(i) Wings of insect, bird and bat.
(ii) Spiny anteater and scaly anteater belong to different orders of class-Mammalia.
They have acquired similar adaptations for food, e.g. leg ants, termites and insects.
(v) Embryological evidences Study of comparative embryology shows common
patterns of development.
(a) The principles of embryonic development were given by Von Baer.
(b) Ernst Haeckel propounded The theory of recapitulation or Biogenetic law which

states that an individual organism in its development (ontogeny) tends to repeat the
stages passed through by its ancestors (phylogeny), i.e. ontogeny recapitulates
phylogeny.
(c) This means that the life history of an animal reflects its evolutionary history.
For example, during the life history, frog’s tadpole larva resembles fishes, the
ancestors of amphibia.
The presence of gill clefts in all vertebrate embryos including human provides a
strong evidence in support of organic evolution.
(vi) Anthropogenic evidences Excess use of herbicides, pesticides, etc has resulted
in selection of resistant varieties in a lesser time scale. This is also true for microbes
against which antibiotics or drugs have been used. All these evidences tell us that
‘Elvolution is a stochastic process based on chance events in nature and chance

mutation in the organisms’.