Time flew by, a thousand years, ten thousand years, a hundred thousand years passed, and the Green Star Civilization had long since left this starry sky, running off to wreak havoc elsewhere. During this phase, Humans entered the Old Stone Age.
On Karena Star, in the Second Epoch, a new intelligent species, the Half-sphere Civilization, was born!
A planet suitable for the evolution of life successively developed two different intelligent species, which was not unusual.
Just like on tiny Earth, Intelligent People, also known as Humans, were a rather clear-cut example of an intelligent species.
But Humans were not the only intelligent species.
Just as with the Thai Macaque, West African chimpanzees, Black-belted Wavy-tailed Monkeys, and White-faced Tailed Monkeys, these species might also have progressed into the Old Stone Age; in the distant future, if not for the intervention of man, they also had a certain probability of becoming intelligent species.
