Professor Zheng's light and shadow froze for a moment again, then he smiled again and said, "The word 'human' has biological, cultural, and political ...... The meaning of multiple levels, I can only say that from a biological point of view, there is no reproductive isolation between earthlings and most of the intelligent races in the immortal cultivation world and the illusion world, including the orcs, sea tribes, and mermaids in the illusion world. ”

"Even mermaids don't have reproductive isolation?"

Chu Ge and Shi Meng stared at each other with wide eyes, and after thinking for a long time, they still felt incredible, "But...... How? ”

This time, Professor Zheng's light and shadow were completely frozen.

After a full three seconds, he said dryly: "This is a good question, students are welcome to think independently, the next question." ”

"Okay."

Chu Ge scratched his hair, "That is to say, the humanoid intelligent life of the three worlds originally came from the same source?" So how did we disperse into the three worlds, and also developed a completely different power system, why is there no magic in the immortal cultivation world, there is no supernatural power in the illusion world, and there is only technology on the earth? ”

"The answer to this question is still mysterious, hidden in a thick fog, but the academic community has also thrown out many hypotheses, and the first thing to be clear is that the ability of humans to migrate is far beyond all of us think."

Behind Professor Zheng, the light and shadow changed, and a picture of the ancient earth more than 100,000 years ago emerged.

In the painting, on a hot continent with abundant water and grass and wild beasts, a group of primitive people with slender bodies and hairy hair and blood, armed with stone spears and stone axes, are chasing the beasts and migrating north.

This is the picture of the ancestors of mankind, out of Africa, spreading to the entire planet.

"Back in the wild and ignorant years, our ancestors did not have the help of any modern weapons, paved roads and any automatic means of transportation, relying on simple stone spears and feet, step by step out of the land that first gave birth to them, towards the plains, towards the mountains, towards the sea, towards the rainforests, towards the frozen snowfields, and embarked on a courageous migration path."

"In the tens of thousands of years that followed, human footprints trodden all the habitable lands on the planet and exterminated the large beasts there, becoming the masters at the top of the food chain.

"Even the vastness of the ocean could not stop the progress of mankind, and with the most rudimentary canoe, mankind was scattered to the archipelago in the depths of the ocean.

"But at this time, mankind was far from inventing the concept of 'country', let alone any 'imperial expedition', and the people scattered all over the country were completely unaware that they were a unified civilization and were unfolding an unprecedented hegemony on this planet.

As a result, the scattered and settled human beings stopped their progress and slowly closed themselves, and according to the characteristics of the local environment and climate, they developed distinctive cultural customs, social forms, and moral laws, and even skin colors and physiognomy.

In this way, when the darkness of the Middle Ages was about to pass and the age of global discovery came again, the scattered human beings saw their own kind for the second time after tens of thousands of years.

"But at this time, it is difficult for people who are completely different in appearance and spirit to recognize each other as their 'compatriots' - when the Franji man riding a tall horse and holding an arquebus found the Incas wearing brilliant feathers and using human sacrifices, I am afraid that the other party may be their own compatriots, if at that time, they were all familiar with the concept of 'aliens', they would definitely think that each other was aliens."

Chu Ge thought for a moment and said, "Are you saying that the relationship between the earthlings and the natives of the Immortal Cultivation Realm and the Illusion Realm is like the relationship between the Francos and the Incas?" Could it be that the intelligent life of the Immortal Cultivation Realm and the Illusion Demon Realm also slowly spread out from the earth more than 100,000 years ago? ”

"As a possibility, why not?"

With a wave of his hand, Professor Zheng saw a picture of thousands of miles of ice and snow drifting behind him, and in the ice and snow, a group of humans wrapped in heavy fur were trudging through the mottled rock formations between the ice fields.

"In the prehistoric era of 10,000 to 30,000 years ago, at the end of the last ice age, the land bridge between Siberia and Alaska was revealed.

"Let our imagination run wild and suppose that instead of crossing a land bridge between Siberia and Alaska, these ancient ancestors crossed a gap in time and space? What if the opposite side of the gap in time and space is the Immortal Cultivation Realm or the Illusion Demon Realm, which is a piece of Cave Heaven and Blessed Land that is more suitable for survival than North and South America?

"Because I don't know much about the Immortal Cultivation Realm and the Illusion Realm, many people will think that they are two extremely distant and difficult to reach foreign lands - in the concept of the three-dimensional universe, it may be like this, but with spatial gaps, or 'four-dimensional bridges' to communicate with each other, it is very likely that crossing to the other world is simpler than crossing the land bridge under the ice and snow and crossing the ocean with a canoe."

That's true.

Whether it was the little palace master or the Dongban Iron Pillar, it didn't take much effort to travel to the earth.

Judging from the words of "Colonel" Ning Lie, the earthlings have traveled to the other world, and the main danger is not in the process of crossing.

After crossing over, although the little palace master felt that the air was dirty and the concentration of aura was too low, she could still breathe normally, and the food on the earth did not cause her much trouble.

This shows that the similarities between the earth, the immortal cultivation realm, and the illusion realm far outweigh the differences.

Even if a primitive person tens of thousands of years ago accidentally crossed into the realm of cultivating immortals or the realm of illusions, it was possible to survive, right?

"Tens of thousands of years ago, the barbaric era, and today's environment is very different, many experts and scholars believe that it was an era of spiritual energy on the earth, and even flooded, perhaps at that time, there were countless very stable space gaps between the earth and the immortal cultivation world and the illusion world, like a very safe and fast passage, which could help the ancient ancestors to easily travel through the past."

Professor Zheng said, in the picture behind him, on the ice and snow, a very strange mirror hundreds of meters high, perpendicular to the ground, suddenly appeared.

In the picture, the ancestors wrapped in heavy fur and holding stone spears and bone blades first bowed to the mirror, then approached the mirror curiously, and tentatively threw the stone spear and bone blade over, as a result, the surface of the mirror rippled with mercury, and the stone spear and bone blade disappeared.

Finally, a bold ancestor carefully stretched out his hand to the mirror, first his hand, then his arms, shoulders, and head, and he traveled directly through the past.

After a while, many clansmen were still frightened, and he jumped out of the mirror with his fat prey in his hand, dancing and saying something happily, and then, the whole team of clansmen followed him, and through the mirror, the group traveled to the other world!

"Perhaps, when the earth was in the Ice Age when food was scarce and the temperature was extremely low, the Immortal Cultivation Realm and the Illusion Realm had a comfortable environment and abundant food, and there had never been such a human being who was good at using tools and full of wisdom.

Professor Zheng said, "In this way, a large number of human ancestors crossed into the other world, took root, sprouted, and became today's immortal cultivation civilization and magic civilization. ”

"It's incredible."

Chu Ge muttered, "Even if the spatial gap really exists, how many ancient ancestors can just discover it and use their courage to travel through the past!" ”

"It doesn't take much, even a few hundred or thousands of people are enough."

Professor Zheng said unhurriedly, "I'm afraid this student doesn't have much concept of human reproductive ability, although in the whole nature, we are not the most productive species, but with the escort of civilization, our infant survival rate is the highest among all species, and it was the case tens of thousands of years ago."

"In the early battles between Homo sapiens and Neanderthals, our race was suppressed to a few thousand people, but once we gained the upper hand, it multiplied to seven billion in just a few tens of thousands of years – and this is the result of careful control, and if we have enough food and space, even 70 billion, 700 billion is not a problem.

"Therefore, in the Immortal Cultivation Realm and the Illusion Realm, which are more abundant in spiritual energy, as long as there are hundreds of ancestors, after hundreds of generations, there are billions of people, which is enough to carry the development of a civilization, which is completely possible."

Although Chu Ge didn't believe it very much, after thinking about it, there was nothing to refute.

"It turns out that we are the ancestors of immortal cultivators and magicians, this thing, the water washed the Dragon King Temple!" Chu Ge patted his thigh and said.

The little palace master was not convinced.

"Professor Zheng, is this really the case, but people can't believe it!"

She said in delicate Mandarin, "According to you, the earthlings traveled to the Immortal Cultivation Realm and the Illusion Realm tens of thousands of years ago and became the ancestors of the Otherworld, but I heard that many Otherworldly myths and legends have a history of hundreds of thousands or even millions of years, as if millions of years ago, the Otherworld developed a prosperous civilization - what is going on?" Could it be that in fact, it is the aliens who have crossed over to the primitive earth and become the ancestors of the earthlings? ”

"Who is this?"

After listening to the little palace master's coquettish speech, Shi Meng looked at her seriously a few times, and asked Chu Ge in a low voice, "Your girlfriend?" It's beautiful! ”

"No, don't talk nonsense."

Chu Ge hurriedly waved his hand to deny.

He is not a decent gentleman, mainly because he is afraid of the little palace master's father, it is better not to make this kind of joke casually.

"She's very strong, ordinary men can't bear it, don't mess around, otherwise the consequences will be very serious." Chu Ge kindly reminded Shi Meng.

"Oh......"

Shi Meng's eyes went back and forth between Chu Ge and the little palace master, and he nodded, "I understand." ”

I don't know what this seemingly honest guy understands.