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) give rise to the embryo proper. Embryos that are to be used in chimeras can further be genetically altered in order to specifically contribute to only one part of chimera. An example is the chimera built off of ES cells and tetraploid embryos, which are artificially made by electrofusion of two two-cell diploid embryos. The tetraploid embryo will exclusively give rise to the trophectoderm and primitive endoderm in the chimera. There are a variety of combinations that can give rise to a successful chimera mouse and — according to the goal of the experiment — an appropriate cell and embryo