Age of fossils in the past was generally determined by radiocarbon method and other methods involving radioactive elements found in the rocks. More precise methods, which were used recently and led to the revision of the evolutionary periods for different groups of organisms, includes

Options

A. study of carbohydrates/proteins in fossils
B. study of condition of fossilisation
C. Electron Spin Resonance (ESR) ,md fossil DNA
D. study of carbohydrates/proteins in rocks

Answer

C

Explanation

Electron Spin Resonance (ESR) measures number of c~argcs occupying deep traps in crystal band gap. The basic principle of ESR is same as those for hm1inescence, i.e. electrons become trapped and stored as a result of ionisino· b radiations, e.g. dating of tooth enamel