Besides knowledge of metals, the Vedic rishis were also acquainted with fossils. Vedic people might have performed study of fossils or Paleontology. One of the Rig Vedic verses states – “O Saraswati, all life is in thee, thou art divine.”(Rig Veda II, 41.17). The poetic expression appears to be an original idea in the research of geology, as the poet has apparently hit upon some geological discovery – that vitality has first come into play in the region of the Saraswati River.
While discussing the region as that of the origin of life, N.B. Pavgee (Vedic Discoveries in Geology), with the help of the above verse of Rig Veda, says, “Vedic research in geology convey the idea that river Saraswati was supposed, from the geological point of view, to be the scene of vitality and the region where life had first commenced after the Earth cooled down, as the verse says that all life or generations are in the Saraswati River.
Reference has been made in Rig Veda about the first appearance of herbs and weeds. It is believed that these herbs and weeds appeared some three epochs before the advent of man. This is also mentioned in Taittiriya Upanishad, prthviya ausadhya – herbs that appeared on Earth after it cooled down.
The sequence of origination of certain major a group of animals as explained in Hindu scriptures – Agni Purana and Vishnu Purana – seems to indicate that the early Hindus had some concept of evolution.
The sequence known to them – first that of the Paleozoic, a fish (Matsya avatar); the second that of the Mesozoic, a tortoise representing reptiles (Kurma avatara), the third of a boar (Varaha Avatara); followed by a Cenozoic man-lion representing mammals (Narasimha Avatara); and a human dwarf (Vamana Avatara) – broadly coincides with modern evolutionary theory.