The people who inhabit our entire planet belong to the single species Homo sapiens, and are divided only into subspecies, which are also called races. Humanoid creatures of other species in the past inhabited the Earth, and even coexisted with our ancestors - for example, the Neanderthal man is a different species, and the Cro-Magnon man is the ancestor of modern man, our species. There were also Denisovans - at the same times, and modern research proves that different types of people even crossed, producing offspring. However, only one species remains today.
People on the planet vary greatly - in terms of skin color, physique, general features, characters, and many other indicators. But also we all have a lot in common. A lot of interesting things can be told about a person, and some facts surprise even specialists.
When did the first civilizations appear?
It is believed that the first civilizations arose about 10 thousand years ago. Archaeological discoveries prove this: first, a man who originated on the African continent created a powerful Sumerian civilization, followed by other civilizations on the territory of Mesopotamia. Soon after, a state arose on the Nile River, Ancient Egypt.
There are opinions that there were much earlier states. Artifacts dated from earlier periods of time are scattered around the world, and there are few of them. As for the history and evolution of mankind, one can say another thing:
- Our ancestors saw not only mammoths, but also cave bears, giant sloths and other megafauna;
- The genes of Neanderthals and Denisovans can be traced to this day, although past scientific discoveries have disproved this fact;
- Mankind has experienced various catastrophes along with the planet, and the next time the Krakatau volcano erupted, the population of ancient people decreased to 10 thousand or less — we were on the verge of extinction;
- A person does not have powerful teeth or claws, people survived primarily thanks to the mind. Some advantages were given by upright posture.
The human body and its amazing features
Studying a person, it is worth considering not only his past. Some features of the body structure will surprise no less than historical or archaeological discoveries. So, for example, not everyone knows that the human heart has its own autonomous life support system. Gastric acid is so concentrated that it eats up the organ from the inside - its mucous membrane is forced to renew every 4 months.
In addition, it is worth noting other nuances:
- The total length of blood vessels is 96.5 thousand kilometers - this is enough to round the globe 2 and a half times;
- Despite the weak scent compared to animals, a person distinguishes more than a billion odors;
- Snoring, a person can overcome the figure of 80 decibels - drills work with such noise;
- Neural signals travel through the body at a speed of 240 km per hour;
- Heart rhythms are able to adapt to the music that is currently happening person;
- A person’s waking brain produces so much energy that it could power a light bulb;
- The bones of the body are stronger than steel, although water takes up to 30 percent of their volume;
- Expressing this or that emotion with facial expressions, a person begins to feel it.
All people in the world think in approximately the same way. Except for some points. So, people living in the southeastern direction tend to read not from left to right, but rather, and in the same way they look at pictures, study the surrounding reality. In Asia, most people have imaginative thinking. And there are almost no twins born.
Be that as it may, but all people on the planet have a ton of similarities. And we have no other brothers in mind - the closest species in this regard is the chimpanzee, whose genetics are more than 99 percent the same as human. They also know how to use tools and communicate. Man is a biosocial creature that differs from others in the presence of reason, and thanks to this it stands apart from other representatives of the fauna of the planet.
