Richard Dawkins, even since writing a book titled "The Selfish Gene" has been a proponent of memes as a form of social evolution.

A meme has no physical existence and is just ideas, practices or symbols transmitted in some sort of viral manner from person to person, community to community.

It is a clever idea that through interaction with others societies adapt, evolve and change, exchanging ideas, transmitting knowledge and adapting to other changes. And on paper it all sounds great.

From Wikipedia: