Four reasons that led to the emergence of a person
The fact that a man is a crown of creation, man came up with himself. More precisely, Bible. Modest anthropologists consider otherwise: "unique" human brain – no unique, but the same adaptive body as a trunk of an elephant. And elephant, like all the current animals, can also consider themselves the notorious "crown". After all, from the point of view of evolution, all animals that lived to today are successful. Just someone needs a big brain for survival, and someone – fast legs. Homo Sapiens could well and not appear on Earth or completely disappear as other types of Homo. But this did not happen, to which various random factors contributed. We tell what.
Event: Listening to dinosaurs
Time: 65 million years ago
Result: Development of mammals, impairment of vision, improved sense of smell, developed brain
Mammals appeared on Earth about 200 million years ago, at the end of the triad period, that is, long before the extinction of dinosaurs. But it is the major representatives of the predatory lizards prevented mammals to develop, drinking themselves, and their cubs.
Millions of years the fate of our ancestors was rat sizes, the constant need to hide on the nora and eat what fell. But it is this unpretentiousness that seems to help them survive when the giants disappeared 65 million years ago. Scientists believe that if this were not happening, mammals would still be imparted on the backyards of the animal world, would be small and not so diverse, therefore, and what civilization would not be.
Millions of years the fate of our ancestors was rat sizes, the constant need to hide on the nora and eat what fell
However, the fact of the existence of dinosaurs also helped. Paleontologists believe that the lizards were probably a day hunter, since this strategy is observed with the absolute majority of birds. And after all, Pernaya – this is the lived dinosaurs who lived to this day (they are called bird dinosaurs, and all extinct – inadicious). Therefore, there was nothing to be a mammal, how to become night hunters: not only not to enter into competition with "the strong world of this", but not to become their prey.
For this reason, the mammals developed the so-called dichromatic vision – most of them and this is still able to distinguish between two colors of combinations of only two colors. Primates, including a person, in the process of evolution, vision became more complicated and became trichromatic – it is likely to distinguish the shades of ripeness of fruit. (Read the material "My Planet" about how the animals around the world see.)
But before the birds, we still far away – it is a tetrachromatic, and the world they see where in brighter paints than a person. But as compensation for daltonism in mammals, the best sense of smell. And it is the olfactory shares of the brain subsequently evolved in large hemispheres, which are responsible for intelligence.
If dinosaurs were not extinct, alternative "mankind" could be all the same birds. It is from them, as paleontologists believes, there was some chance to become intelligent, especially since many of them today demonstrate an outstanding intelligence. Take at least the parrots and Voronov – the Novokhaledonian appearance of the latter even knows how to produce the tools of labor with the help of beak. True, in order to become truly reasonable, the birds would have to say goodbye to the flight and again become flutter, because the flight still does not imply the presence of a big brain and, as a result, severe head. However, with this task, they definitely coped with this task, because representatives of the low-butter feathers many and today are penguins, trustee shepherds, ostriches, kiwi, etc.
Event: changing of the climate
Time: 3-2.5 million years ago
Result: Strengthening the tendency to straighten, hair loss on the body, instrument activity, brain development
The number of cooling and warming in the history of our planet is so great that Grech Tunberg and did not dream. And they are all caused by natural reasons. For example, one of the factors of myocene cooling 3-2.5 million years ago was the change in the inclination of the earth’s axis. The climate has become colder and land, which led to a reduction in forests in Africa and the expansion of Savann. Gominids who lived under forest crowns began to fight for food.
By that time, our ancestors: Sachelantopa, ORRYRINS AND ARDIPITEY -, the benefit has already moved on two legs. But they lost in the battle for the food ancestors of modern gorillas, orangutans and chimpanzees. Therefore, those remained to live in the forest (where they live to this day), and our grandfathers went to Savannah. Perhaps it was even more promoted directly: when you stand on two legs, it is better to see predators, squeezed in high grass, and also reduces the area of the body that heats the hot African sun.
Experiments have shown that in the warm climate binary movement over long distances is energetically more profitable than the four. To heat up less, our ancestors probably partially lost their hair on the body (more precisely, they became much shorter and thinner), leaving the long hair only on the head – as a cooling "pillow" from the sun rays.
When there are no long wool, young people are not for changing, so the mothers had to wear them in their hands, which probably even more contributed to the transition to straightening.
As a result, 3.4 million years ago, the first stone tools of labor appeared. After all, the hands of the ancient letters were now free, they began to conveniently take stones and scrape meat from the bones of animals, and still fight back from predators. Meat food meat, as well as active instruments, in turn, helped grow the brain. Modern scientists, however, do not tend to believe that if the climate had not changed, our ancestors would remain to live under the crowns of trees, like chimpanzee. But the fact that drought clearly contributed to the evolution of hominids, no doubt causes.
Without a cat and life is not
Event: Friendship with savory cats
Time: 2 million years ago
Result: Brain development, collective behavior, instrument activities
Humanity in the 21st century unites Internet and love for cats. But it seems that these warm relations began a long time ago – approximately 2 million years ago. And then do not people cared for cats, but quite the opposite.
True, the cats in those days were more frontier, because we are talking about saber-chassis – Meganteriones, weighing about 100 kg, and even larger homoteries, the mass of which reached 190 kg. Due to specific teeth, these predators left a lot of meat after the feast than and used the Padalers. Such were hyenas and. our ancestors. To compete with hyenas, they had to develop fast running skills, endurance, and still-hidden and caution, so as not to fall into the mouth of saber-toothed cats.
Simultaneously with our immediate ancestors there were several parallel humanities of different degree of advanced and backwardness
In addition, it has further contributed to the use of labor tools: the better you get prey, the more you can eat and carry in a secluded place about the supply. The fact that "cooperation" with cats helped to survive our ancestors, of course, a hypothesis, but it adheres to very many paleoanthropologists.
And in the fact that the ancestors died behind Megantereon, there is no doubt: it is indicated by traces of the dental of the last on the bones of ungulates, which are overlapped by knockers of stone guns. By the way, when the saber-toad cats extinct 1.5 million years ago, our ancestors moved to more complex tools of labor: from Olduva technologies to Ashhelsky, because new conditions required and more advanced adaptation. So here and here without the participation of the cats did not cost.
Brothers in mind
Event: The disappearance of Neanderthals, Denisovsky and other types of man
Time: 28 000, 30 000, 60,000 years ago
Result: man of modern appearance
Evolution is not like a tree, but on a bush. Including the evolution of man. It is not surprising that at the same time with our immediate ancestors there were several parallel humanities of different degrees of advanced and backwardness.
Today, scientists believe that Neanderthals were not more stupid of our forefathers and, perhaps, exceeded them in medicine, but probably have a smaller ability to work.
Denisovtsy, most likely, were more developed than Sapirens. They knew how to make more advanced decorations than our ancestors. So, in the Denis Cave, where these people lived in the corresponding layer found a chlorite bracelet – a stone that changes the color depending on the lighting, the marble ring and the biggest needle in the world history of Paleolithic.
But the people of Flores (Hobbits) who lived on the island of Flores from 60,000 to 100,000 years ago, although they are considered parallel mankind, but rather reminded the chimpanzees – and on appearance and development. They did not leave offspring.
Surely there were other types of Homo’s kinds, about which we do not yet know or know very little, because in our genome there are traces of unknown lines of humanity.
By the way, we inherited a small percentage of Neanderthal genes – 1-2.6% (except for indigenous people of Africa, who did not leave the continent and were not mixed with them). And the Australian aborigines, Melanesians and Papuans of New Guinea also have admixture of Denice. But it is also very small – 3-6%. What would happen if parallel humanity were not extinct, it remains only to guess. Most likely, they would simply mix with our ancestors (as partially happened) and today we would have a little different appearance.
How it happened that of all kinds of people people survived only Sapirens? There is no exact answer – probably this is another chain chance. Neanderthal Most likely destroyed their small number and many other reasons, including eruption of phlegrey fields, which occurred 40,000 years ago. As a result, Neanderthal disappeared 28,000 years ago. Even earlier, 30,000 years ago, Denisovsky died out. There are versions that their population was originally alike as Neanderthal. And they could also "finish" climatic changes, and even competition with sapiens. And the hobbits probably thwart the volcanoes or simply destroyed our more advanced ancestors that were sailed to the island of Flores.