From Agatha Jadwiszczok:
In your review of that silly movie that just came out ("Percy Jackson & The Olympians: The Lightning Thief"), you complain about the Greek God-human breeding. As someone who was a very devoted student of Greek mythology as a kid, I can tell you that Greek God-human breeding was actually very, very common in Greek myth. The movie actually is accurate about this and consistent with Greek mythology. Zeus and the other Olympians were constantly and permanently knocking up princesses, queens, nymphs, sirens, lesser goddesses, warrior women and just plain fair maidens who bathed in the pool with their handmaidens. And the handmaidens, too, sometimes. Zeus even managed to impregnate mortal women when he was a swan or a bull.
Hercules was the illegitimate child of Zeus and a mortal woman, as were Perseus, Helen of Troy and Minos (among other very, very famous offspring of Zeus). Yep, the Greek God family tree is very, very tangled. The genealogy is near impossible to try to map.
And ancient Greeks who literally believed in their religion also believed that Zeus could produce offspring with human women in the real world; among the many people who did was Alexander the Great's mother, who claimed that Zeus had fathered her son. Alexander the Great was alleged to have actually believed this himself.