A brief history of copying

In a grand historical view of copying on the planet, we have something like this:

Genes -> Ideas -> Memes

• Organic copying resulted from the origin of life;
• Psychological copying which evolved within minds;
• Cultural copying which evolved between minds.

Each stage led to its own explosion of living systems. Nucleic acid copying led to the Oxygen holocaust. Psychological copying led to the Cambrian explosion. Cultural copying led to the modern technology explosion.

There's some controversy over whether the last stage should be split into two - with human copying and machine copying being distinguished from one another - with a meme-driven human explosion preceding the ongoing technology explosion. Probably the main proponent of this split is Susan Blackmore.

Another controversy surrounds the origin of life. Probably there were copying systems before DNA. Also there were probably copying systems before the origin of life. A. G. Cairns-Smith argued forcefully in Genetic Takeover that there was no such thing as pre-biotic evolution. It now looks as though he was wrong - and that pre-biotic copying and selection are commonplace. Their role in the origin of life seems probable - though somewhat uncertain.