Greek mythology to dominance is frequently called the "Dorian invasion". The Lydian and later the Macedonian kings, as rulers of the same rank, also became Heracleidae. Other members of this earliest generation of heroes such as Perseus, Deucalion, Theseus and Bellerophon, have many traits in common with Heracles. Like him, their exploits are solitary, fantastic and border on fairy tale, as they slay monsters such as the Chimera and Medusa. Bellerophon's adventures are commonplace types, similar to the adventures of Heracles and Theseus. Sending a hero to his presumed death is also a recurrent theme of this early heroic tradition, used in
Chimera (genetics) was a sexual chimera; as four percent of Roku's blood cells contained two x chromosomes. A major milestone in chimera experimentation occurred in 1984, when a chimeric geep was produced by combining embryos from a goat and a sheep, and survived to adulthood. The creation of the "geep" revealed several complexities to chimera development. In implanting a goat embryo for gestation in a sheep, the sheep's immune system would reject the developing goat embryo, whereas a "geep" embryo (sharing markers of immunity with both sheep and goats) was able to survive implantation in either of its parent species. In August