Define fossil. Explain importance of fossils as proof of evolution.

Explanation

Remnants and impressions of organisms which get burried remain preserved underground. These are called as fossils. Study of fossils is an important aspect of study of evolution.
(ii) Carbon consumption of animals and plants stops after death and since them, only the decaying process of C-14 occurs continuously.
(iii) In case of dead bodies of plants and animals instead of remaining constant, the ratio between C-14 and C-12 changes continuously as C-12 is non-radioactive.
(iv) The time passed since the death of a plant or animal can be calculated by measuring the radioactivity of C-14 and the ratio of C-14 toC-12 present in their body.
(v) This is carbon dating method. It is used in determining the age of human fossils and manuscripts.
(vi) Once the age of fossil has been determined, it becomes easy to deduce information about other erstwhile organisms.
It seem that vertebrates have been slowly originated from invertebrates.