Short/Long answer type questions
How do data from biochemical studies support the concept of common descent?
Biochemical investigations helped us in establishing molecular homology or common descend. Homology is also seen amongst the molecules. For example, the proteins found in the blood of man and ape are similar. The phylogeny of an organism can be traced by using the base sequence in nucleic acids and amino acid sequence of proteins in related organisms. Following are other pieces of evidence of common descent from biochemical investigations:-
(i) The Protoplasm:
The basic substance of living body contains nearly the same elements compounded from roughly the same proportions of proteins, carbohydrates, fats, water am other substances.
(ii) Enzymes and Hormones:
In a particular group of plants or animals, similar enzymes and hormones occur. This is specially true of some of the digestive enzymes in animals. In almost all the green plants belonging to diverse groups photosynthetic enzymes are the same. The indicates seemingly a common ancestry of all green plants.
(iii) Blood Groups:
The blood of human has been classified into four well known groups ‘A’, ‘B’, ‘AB’ and ‘O’ on the basis of antigen-antibody reaction. Red blood cells may carry antigen ‘A’ or ‘B’ or both ‘AB’ or ‘O’ (none) and person’s blood group is named accordingly.