ospalh quoted Hybrids by Robert J. Sawyer (Neanderthal Parallax, #3)
Content warning plot relevant genetics
But every evil man, by definition, had to have a Y chromosome (...)
(...)
Testing for a Y chromosome was easy enough: just pick a gene from the Human Genome Project database that appeared only on that chromosome.
— Hybrids by Robert J. Sawyer (Neanderthal Parallax, #3) (Page 320)
That is oddly unspecific, and oddly specific.
She wants to genetically identify men. The choice for that is not »a gene from the Human Genome Project database that appeared only on (the Y) chromosome«. It is to use SRY. That gene is called the ex-determining region of Y-chromosome, but it was discovered by looking at XX male patients. Again, by 2003 (©-date), that was an old hat, known for more than 10 years.