What the ancestors of Homo sapiens looked like: Who could not pass natural selection, and with whom everything is not so simple

2024 Author: Richard Flannagan | [email protected]. Last modified: 2023-12-15 23:55

The transformation of Australopithecus into a modern-type man did not come true, of course, overnight - the process took hundreds of thousands and even millions of years. Everything happened, as is now known, extremely slowly, and at the first stages of anthropogenesis much longer than at the subsequent ones. Here is what is interesting: in addition to the links in the chain of "transformations" into a Homo sapiens, there were other "relatives" of him - who did not pass the selection, but did not sink into oblivion either. These are kind of "uncles" of modern people who passed on some of their genes to their descendants.

From monkey to working man

Practically nothing about human evolution can be said for sure - millions of years of history have left not much material evidence regarding the past of this genus - Homo, which includes many extinct species and only one existing one - Homo sapiens. Nevertheless, science with its capabilities in the study of the genome has made such a step forward over the past decades that even on the basis of meager facts and findings, it is possible to build reliable theories of the development of man as a genus. Gene traces preserved in the remains of fossil people, together with other anthropological data, help to build an evolutionary chain and distinguish different types of humans.

For tens of millions of years, nothing happened to the animal ancestors of man - and yet scientists here, too, manage to distinguish between different types of ancient orangutans and their monkey counterparts. Australopithecus is considered the immediate ancestor of modern humans. A highly developed variation of it was a skilled person - nothing, by and large, especially not able, but nevertheless, as it is believed, used for his needs primitively chopped pebble tools. People of this species have inhabited the Earth for half a million years, the very first individuals, according to scientists, appeared about 2, 8 million years ago.

A skilled man (homo habilis) was short - about 120 centimeters tall, had a flat nose and protruding jaws, and the first toe, unlike its predecessors, was no longer set aside, but was located together with the rest of the toes - it was time to move on two limbs. One of the varieties of skillful man (or even a separate human species) was the Rudolph man, he was discovered in 1972 in the area of the Kenyan lake Rudolph. There is an ambiguity that science has not yet been able to clarify: Rudolf man is either the ancestor of living people, or their "uncle", that is, a dead-end branch of evolution.

The next stage of human development and the next direct ancestor of modern people was the working man (homo ergaster). The most complete of the skeletons that have survived by this time belongs to a teenage boy who was buried in what is now Kenya about one and a half million years ago. It is interesting that at first only the frontal bone of the skull was discovered, and only a few years later it was possible to find other parts of the skeleton.

The following conclusions were made regarding the working person: people of this species were quite tall (up to 180 centimeters in height), they may have invented a double-edged chopper and could use fire. However, hunting did not bring the main amount of food to the working person - these people ate mainly carrion and plants.

From Homo erectus to Homo sapiens

One of the next stages of evolution was the emergence of Homo erectus, who had already mastered the manufacture of stone tools quite well and used spears with a long wooden tip in hunting. The fact of bipedal locomotion was established from bones found back in 1891 - then this type of fossil man was named Pithecanthropus. Homo erectus was constantly looking for food for himself, while it was established that these people lived in large communities, took care of their fellow tribesmen who lost their ability to work.

The Heidelberg man, close to the erectus man, was identified as a separate species. Since people of the past settled over a vast territory, species are often tied to geographical names. The Heidelberg man got his name because the remains of a skeleton of this species were found near the German town of Heidelberg at the beginning of the last century. This ancestor of Homo sapiens, most likely indirect, first appeared in Africa about 800 thousand years ago and settled in Asia and Europe.

A close relative of Homo sapiens, but still not his direct ancestor, was the Neanderthal man. The oldest remains are about 500 thousand years old, and this species got its name thanks to the find of a skull in the Neandertal valley in Germany. Neanderthals coexisted simultaneously with the ancestors of modern humans of the sapiens species and therefore passed on a number of genes. According to studies, about two percent of them have DNA from modern people (except for Africans - in this case, we are talking about a lower number). Some scientists, however, argue that these genes could have passed to modern humanity not from the Neanderthal man, but from a common ancestor with him.

These "relatives" were already in many ways superior to the more ancient species of man. They made tools of labor - already without any reservations and doubts, they had primitive knowledge about medicinal plants and used them, they may have mastered something like speech. To the merits of the Neanderthals also include the creation of the first musical instrument known to historians - a bone flute with four holes. In this regard, it seems quite unfair that the fact that in the 19th century it was proposed to give this species the name "stupid man", giving it a place in the evolution between apes and the first people.

Neanderthals ceased to exist about 40 thousand years ago, and the reasons for this are different. Perhaps it was climate change, or the weakening of the Earth's magnetic field and increased exposure to solar radiation, or some diseases that led to the extinction of the species. Another likely reason is the competition with the Cro-Magnons - the early representatives of modern man.

Cro-Magnons (from the name of the Cro-Magnon cave in France, where the remains of these ancient people were discovered) appeared much later than the Neanderthals: 130 - 180 thousand years ago, they began migrating from the African continent. Cro-Magnons have taken a huge step forward relative to all their other "relatives". Their body structure allowed them to run faster, spend less calories than Neanderthals, and in addition, in a short period of time, this human species mastered something that was not familiar and not available to its predecessors.

Cro-Magnons adapted much better to natural conditions, they built rather complex relations within their communities, the technology of making tools made it possible not only to equip life, but also to hunt effectively, without risking being crippled or killed directly in a fight with animals, but using throwing weapons like a spear … The Cro-Magnons communicated a lot with each other, using a semblance of speech, they tended to value objects of art, the dead were buried in observance of funeral rites. The domestication of the dog dates back to the Cro-Magnon era; this species is called the ancestor of all modern homo sapiens. 20 thousand years ago Cro-Magnons already inhabited all of Europe.

Dead-end branches of evolution?

The scheme of human evolution in the early stages of the development of science looked quite simple, but now it is a complex "family tree", many branches of which remain insufficiently studied or not open at all. Anthropology is full of mysteries: for example, scientists cannot yet definitely identify the remains of people found on one of the islands of Indonesia in 2003. Several skeletons, whose age is estimated at 60-100 thousand years, once belonged to people of very small stature - no more than one meter. This possible separate species was called by man the Floresian, and his discovery gave rise to many different versions.

Due to the fact that the find contained a single skull, the space for research was extremely limited, and for interpretation, on the contrary, it was wide. The Floresian man was given the nickname "hobbit" - because of his height, and why these people were so much lower than their contemporaries - is it connected with the fact that they lived in special conditions, was it a pathology, or is it still about some that in a separate form - only to be found out. One of the possible "great-grandfathers" of Homo sapiens is the Idaltu man, his last representatives lived on Earth about 150 thousand years ago. Whether he was one of the dead-end branches of evolution or contributed to the formation of the modern human genome is still unclear.

For a long time, representatives of the genus Homo changed, slowly but irreversibly: the skull and brain volume increased, the structure of this most important human organ became more complex, the skills of bipedal locomotion, which cost the female representatives of difficult childbirth, were improved, the tibia was lengthened, which made it possible to improve the skills of the hunter. From fragments of jaws or even some teeth, parts of the skull and other bones of the skeleton, found in the same historical layer with extinct or prehistoric animals, scientists concluded that a new species had been discovered or that ideas about an already discovered one were deepened.

At the same time, despite the already substantial number of "cousins" and "second cousins" species, it remains undeniable: modern people do not have any biological differences that would allow dividing the species of homo sapiens into subspecies. From this point of view, modern man is monotonous, in contrast to many of those human species that once arose and disappeared.

But how scientists distinguish the prehistoric tools of ancient people from ordinary stones.