Human/emugan hybrids are scientifically known as homo sapiens sapiens × homo sapiens extraterrestris.
Hybrids are classified according to the percentage of ancestry and generation. Class 1 are half emugan man and half human. All first generation hybrids are class 1.
Class 2 are divided in 2e, who are 75 % emugan and 25 % human, and 2h, who are 25 % emugan and 75 % human.
Class 3 are divided in 3e, who are 87.5 % emugan and 12.5 % human, and 3h, who are 12.5 % emugan and 87.5 % human.
The offspring resulting from the mating of hybrids from the same class but each division will be class 1. The offspring resulting from the mating of hybrids from different classes will be classified following the following formulas:
- Xe + Ye = X.Ye
- Xe + Yh = Y.Xh
- Xh + Ye = Y.Xe
- Xh + Yh = X.Yh
X and Y are the classes and X is smaller than Y.
There aren't more classes because in 2094 began the Single Species Project. The goal of this project was to interbreed both species to eventually create a single species. The classification system became obsolete in 2184, when scientists declared the species completely merged into a single one named humegan, a.k.a. homo sapiens hybridus.