In 9102, the world government proposed new legal rules that prohibited the description of the part below the neck. Young humans cannot know how to reproduce
In 9144, the only remaining human scientist developed a gonadoid at the age of 92 and injected it into the human scalp, so that humans can survive.
In 10,000 years, humans completed their biological evolution and became new humans. The new humans do not need the part below the hair, so the parts below the neck have degenerated. Hair evolved with nerve endings that took over the work of pre-human limbs.
In 15,000 years, new humans completed their differentiation. Since different hair colors contain different pigments, the pigments merged with the gonads to produce different differences. Therefore, people with the same hair color could not breed offspring, only different hair colors could.
In 17000, scientific and technological research on new humanity began and entered a period of development.
2019, Now.