Up to now, Professor Kangda's so-called non-keynote speech already has a theme, that is, there is nothing special about human beings.

"Many species can be grouped into the same family, just like tigers, lions and kittens belong to the feline family, whether it is a fox or a wolf or a puppy, this belongs to the canine family. ”

Professor Conda continued his lecture.

"As long as it's all animals in the same family, as long as you keep going up, you can find the ancestor of a certain male or female, and the current big lion and your kitten can be traced back to the same ancestor 25 million years ago. ”

At this point, everyone understands that human beings, like other animals, are just one species and belong to a certain family.

"There is nothing special about human beings, human beings are also of a certain family, but human beings don't want to admit that human beings want to be a separate family, that is, human families, and do not want to have any distant relatives and close neighbors, but this is not the case, whether we accept it or not, we humans belong to the family of many cousins and cousins and the like, a bunch of apes, whether it is a chimpanzee, or a gorilla, or an orangutan, are all our relatives, especially chimpanzees, that is definitely a cousin relationship, that is, tens of thousands of years ago, a female ape gave birth to two daughters, one became the ancestor of all chimpanzeesand the other has become the grandmother of all our human beings. ”

When Professor Kangda said this, the students on the scene became very serious.

"Do you know why we dominate this world?" Professor Conda tapped his head, "yes, this is the place." ”

"Generally speaking, the average brain volume of a 60-kilogram mammal is 200 cubic centimeters, but what about us? 12 to 1,004, and if you go back to ancient times, the brain capacity of human beings at that time was also 600 cubic centimeters. Professor Conda was in high spirits.

Of course, some people say that people are not creatures at the top of the food chain, yes, simply speaking, people are indeed not qualified to stand at the top of the biological chain, but people can do it with their brains, dare to ask what species can compete with humans now?

Human beings use their wisdom and are not afraid of any species, no matter how powerful a creature is, can it withstand a few bullets? Even if it is thick-skinned, can it withstand a bazooka? Man-made nuclear weapons can even destroy the entire earth, and what qualifications do other species have to compete with humans for the top of the food chain?

Man can exterminate other species, even himself, but other species cannot.

That's why people today are obsessed with their IQ, why they think that the higher the IQ, the better?

"But have you ever wondered why there are no calculus dogs, why aren't there pigs that know chemistry, why are there only humans who have evolved such a large proportion of thinking organs?" Professor Conda asked again.

The students in the non-biology faculty were at a loss, and some students in the biology faculty were also thinking, and only a few people gave answers.

"Because a huge brain is also a huge burden. ”

Professor Kangda nodded with satisfaction: "That's right!"

The students in the audience were once again focused on Professor Conda.

"Very well, a huge brain is indeed a huge burden, and the structure of the brain is very fragile and not conducive to activity, let alone having to protect it with a huge, hard skull. Professor Conda smiled, "Does anyone have any idea of how much energy is spent in the brain?"

"Even when people are resting and inactive, the brain's energy expenditure accounts for a quarter. ”

"That's right!" said Professor Conda, "although the brain accounts for only three percent of the total body weight of the human body, it can consume twenty-five percent, still at rest and inactivity, unlike other animals, the consumption is very small. Professor Kangda said: "Because the human brain consumes more, so people in ancient times had to pay more, to spend more time looking for food is the first point, the second point is muscle degeneration, muscle degradation is not what humans want, because human beings allocate the energy needed by muscles to the neurons of the brain, so in ancient times, chimpanzees could not win over humans in the link of 'reasoning', of course, if humans and chimpanzees fight, they will definitely be killed, and it is common to be torn apart." ”

There was an uproar in the audience.

"There are gains and losses, human beings want to have a powerful enough brain, they must pay the price of the degradation of other functions of the body, which is why people who are engaged in mental work today will become more and more weak if they do not go to the gym for effective systematic training, and people who are engaged in physical activities do not need to go to the gym to exercise to have muscles, it is because people engaged in mental work have unconsciously converted the energy needed by your muscles into their brains, so the body will become more and more thin or obese, as long as you can't exercise systematically in the gym, this is inevitable。 ”

Professor Kangda's words caused many people to nod frequently.

Because what he said did have a point.

People who are engaged in mental work, although they seem to sit there all day without moving, will also feel tired physically, and people who do not engage in this kind of work will obviously not be able to understand the "tiredness", and will think that mental work is much easier than physical work, but in fact, it is not, there is no light.

There are only three kinds of people in the world, those who use their brainpower, those who sell their physical strength, and those who achieve nothing.

If a person doesn't want to achieve nothing, either use his brain, or exert his strength, and don't want to give anything, then he will definitely gain nothing.

"The reason why man has been able to successfully stand at the top of the food chain and rule the world today has come at a very painful price. Professor Kangda sighed lightly: "While evolving the brain, we need to walk upright on two legs, so that we can improve our vision, so that we can free our hands to do other things, to produce, to make tools, just standing up and walking makes human beings pay great pain." ”

When it comes to the evolutionary history of human beings, it's really sad.

Many students were silent.

The reason why human beings have been able to succeed has been through great hardship.

And now, how can you succeed if you don't want to put in the hard work?

This is the case with humanity as a whole, and it is the same with individuals, who will never gain without giving.

"It took millions of years for our ancestors to develop a skeleton that walked on all fours with a relatively small head, and how easy is it to adjust this skeleton to stand upright and support an oversized head?" said Professor Kangda. ”

Hearing this, many people unconsciously touched their cervical vertebrae.

Nowadays, the vast majority of people have mild or severe cervical spondylosis and low back pain.

"This is the price of becoming a 'ruler'!" Professor Kangda said solemnly: "What's even more terrifying is that walking upright will narrow the hips and limit the width of the female birth canal, not to mention that human beings are still evolving, and the baby's brain is getting bigger and bigger, so it is normal for birth to die, and for this reason, human beings have evolved into a 'premature' species." ”

Many people bowed their heads and whispered to each other about whether Professor Kangda's words were correct or not.

In fact, whether it is correct or not, there is a certain truth, because only premature birth can make the baby's head smaller and softer, and the birth will be smoother, so human beings will choose to give birth early, which is natural selection and is needed for the evolution of species.