From the book Sperm Wars: The Science of Sexby Robin Baker:
“The success of prostitution as a reproductive strategy means that most of us will contain the genes of a prostitute among our ancestors. On average, we should each need to go back through our family tree no further than the 1820s (seven generations) before finding an ancestor who was born to a prostitute (assuming, conservatively, that only 1 per cent of the population is conceived by overt prostitutes.)”