Recombination occurs very time a new sex cell is produced during the crossing over event, Dawkins dispels the random mutation as the only means of genetic shift

Recombination occurs very time a new sex cell is produced during the crossing over event, Dawkins dispels the random mutation as the only means of genetic shift very early in his book "The Selfish Gene" as the crossing over process can split chromosomes mid-gene for longer, more complex DNA sequences.