Re: How did DNA evolve when it can only be made by DNA.

	Amino acids, nucleotides, lipids, and other multi-atom molecules
can be made at random by heat, lighting strikes, sunlight, and other
non-living sources of energy.  Nobody knows exactly how these molecules
came together and got concentrated enough to start reacting with each
other, but there are theories that certain clay particles tend to atract
biological molecules, or that pools at the edge of a lake or ocean that
partially dry out would concentrate the molecules.

	There is another whole field of research devoted to "complex systems"
which studies how non-living chemical reactions can become self-sustaining
and take on some of the properties we associate with life.  We will never
know exactly how life got started, but we can make more and more
intelligent guesses, as we study how organic molecules can be created,
concentrated, and start interacting with each other.

	Some studies of chain reactions and self-sustaining systems apply to other
non-living systems.  For example the way water evaporates, forms clouds,
comes down as rain, and evaporates again, driven by the energy of the sun
and winds.  People have made computer programs that write other programs
and take over control of computers, that mimic life in some ways.