Or are Hybrids Hardier?
I was at the SheKilda crime convention a couple of weeks ago and attended this panel on Cross Genre Writing. It is amazing how many speculative fiction writers also write mysteries. Or you could say, how many crime and mystery writers include a bit of the paranormal in their books.
With plants and animals, if you cross breed the off-spring are hardier. If you keep inbreeding the off-spring develop weaknesses. Not sure if the analogy holds true for books.
The panel talked about whether their die-hard (sorry for the pun) crime and mystery readers were turned off by the paranormal element. For some of them like PD Martin the paranormal element was very slight while, for others, it was a major factor in the plot and world building. They all agreed that it was the story itself that dictated whether to include a paranormal element.
Everyone enjoys a good mystery. Asimov was writing SF-mysteries when he coined the Three Laws of Robotics. Each of the Harry Potter books is based around a mystery (or at least they were when I was reading them to my kids. We stopped after number 3 or 4).
Do you think that combining elements from the mystery genre with the speculative fiction genre makes for a hardier hybrid?