There is a good deal written abut cultural evolution. Over the past year or so I have read some of it. There are two particularly good explanations of the role that culture plays in evolution and both of them use the same strange form of words: exogenetic heredity. The people who use this formulation are Sir Peter Medawar, a Nobel prize winning biologist, and Robert Bringhurst a Canadian poet, typographer and translater.
Here is Robert Bringhurst's formulation of the idea:
With very few exceptions, all the world's birds and mammals train their young. Like human beings, they transmit information from generation to generation in two forms: genetic and exogenetic (inside the genome and outside the genome).
Both of these avenues depend on language. Genetic information is transmitted through chemical languages, whose morphemes and phonemes are made out of ribonucleic acid. Exogenetic information is transmitted through other kinds of language: behavioural languages, some of which are spoken, like the language I am using at this moment, and some of which are silent.
From Wild Language. In The Tree of Meaning. Robert Bringhurst. Gaspereau Press. 2006.
Image from HERE.