Some time ago, it was thought that modern people came from Cro-Magnons, and Neanderthals became extinct. But after the Neanderthal genome project, we found that modern people have from 1% to 4% of Neanderthal DNA.
This lead to the idea that Neanderthals kept Cro-Magnons as sex-slaves:
For example, the self-proclaimed expert on an old thread:
The interbreeding that took place was an exclusively male Neanderthal-female "modern" exchange.
Therefore, there was a master-slave relationship between Neanderthals and "modern" sapiens, with Neanderthals as master, and the "modern" hybrid Cro-Magnon as slave. Leading genetic and archaeological experts agree that male-exclusive interbreeding is usually the result of violence.
The site for the QI TV trivia show drew a similar conclusion:
In 2011, a German team concluded that between 1% and 4% of the genome of all non-African populations today is derived from Neanderthals. This story led to speculation that early Human males may have kept Neanderthal women as sex-slaves, but seeing that the Neanderthals were so much stronger than Humans, it seems to us just as likely that it was the other way around.
Does the idea of a sex-slave relationship between the species (in either direction) have scientific support?