(iii) Cytochrome C : This is an electron-carrier protein found in ETC of mitochondria of all living organisms. Its amino acid
sequence was determined by R.E. Dickerson (1972) in different organisms. He noticed that variations in amino acid
sequence prove phylogenetic relationship.
(iv) Blood and Lymph : The components of blood and lymph, and
their functions are similar in different vertebrates.
(v) Excretion : Physiology of excretion also confirms evolution,
e.g., (a) The adult frog is ureotelic in excretion while its tadpole
larva shows ammonotelism like fishes. (b) The young of a bird is
first ammonotelic, then ureotelic and finally uricotelic.
The complexity of nitrogenous wastes increases with the
evolutionary process. The repeating of ancestral mode of
excretion during the development of an organism is called
biochemical recapitulation.F. Cytological Evidences
- All the living organisms are similar in being:
(i) Cellular in nature and are formed of one (protozoans) or more cells (metazoans).
(ii) Presence of similar organelles having similar ultrastructure and functions.
(iii) In all, the cells are formed of similar material called protoplasm having similar physical, chemical and biological properties.
(iv) Basic metabolic cellular functions are performed in a similar way. All these evidences support that all the organisms are
inter-related and have common ancestry.
These similarities between living organisms at the molecular level is called molecular homology. These similarities confirm the
relationship of all organisms and show their descendence from a common stock.