DP To answer your question find out what a virus uses for nourishment.
Early life forms came out of the evolution of chemicals. Comets with
amino acids they deposited into the Earth's atmosphere. Darwin told us
life was created in small warm water ponds. Very possibly dp that the
first visible life was a green blue algae. Traces of this algae have
been found in rocks in Greenland. They are 3.85 billion years old. Lots
of warm water at that spacetime. bert