Populating the continents: the 5 stages of the dispersion of humans.

A summary of the process of human settlement of the continents.

The populating of the continents took place by means of migrations carried out by the human species, which occurred gradually until they came to inhabit all the possible regions on planet Earth.

The most accepted theory is the one that states that the first Australopithecus lived in Africa, as well as the Homo Sapiens and from that continent they left to the rest of the continents until they populated all of them.

In this article we will a brief review of the populating of the continents by the different human species that have evolved until only that have evolved until only the Homo sapiens.

The dispersion of human species across continents

The settlement of the continents began more than 2.5 million years ago, when beings belonging to a species very similar to that of modern humans, better known as australopithecus (southern ape), whose physical characteristics were very similar to those of the apes we know today, inhabited Africa.

However, the australopithecus were differentiated by their ability to walk with a more upright posture, becoming a bipedal species, and they also developed a remarkable growth in the size of their brain (600 cubic centimeters approximately, which could be up to 3 times larger than that of an ape), which facilitated them acquiring the ability to manufacture small stone toolswhich, in spite of being very rudimentary, facilitated their evolution.

The australopithecus, after acquiring a series of skills, went on to become a more evolved species, the Homo habilisIt is considered to be the first species of human beings.

The Homo habilis was the first human species to leave Africa, reaching the territories of Asia and Europe, and it is in the European continent where it evolved into a new species, the Neanderthal men.and it is in the European continent where it evolved into a new species, the Neanderthal men; while in Asia it evolved into the species of the Homo erectus (upright man).

On the other hand, the Homo habilis that lived in Africa also managed to evolve and, according to several investigations, it is in the African continent where the first beings with an anatomy similar to that of human beings today emerged, being baptized this species with the name of Homo sapiens. This is the one that has managed to survive until today and to which we belong, and whose brain has an average of 1200 to 1400 cubic centimeters, more than double that of an australopithecus.

The Homo neanderthalensisalso known as Neanderthals, were shorter than Homo sapiens. Homo sapiensbut more robust. On the other hand, the Homo sapiens developed a somewhat larger brain, which allowed them to acquire more sophisticated skills, thanks to which they were better able to adapt to the environment and its changes.

More than 100,000 years ago, there was a period known as the "last glaciation" during which the Homo sapiens left the African continent. The settlement of the continents by the Homo sapiens continued when it moved to Asia and then went on to colonize territories until it came to inhabit 5 continents, as we will explain in greater detail below. While colonizing territories, sapiens coexisted with other species of Homo that had arrived previously; however, the other species became extinct and, therefore, only the Homo sapiens managed to survive.

The settlement of the continents by the Homo sapiens

Although the predecessor species to Homo sapiens had managed to reach various areas of the planet, only Homo sapiens has managed to populate the continents in their entirety.

1. Africa

Although the australopithecus spread to other continents, in Africa, in addition to occupying the entire continent, those who lived there also evolved. The human species that existed on this continent shortly before Homo sapiens were the following: Homo rudolfensis (Lake Rudolph man), and Homo Ergaster (working man).

There are many theories that consider that in evolution there was a direct line of descent. However, there are others who claim that during the 2 million years that elapsed since the first humans appeared until just over 10,000 years ago, when only the Homo sapiensdifferent human species coexisted for many years.

Scientific experts in the field are mostly in agreement on the hypothesis that 150,000 years ago, the eastern part of Africa was mostly populated by sapiens with an aspect very similar to the one we live in today.. Likewise, it affirms that 70,000 years ago these sapiens coming from the African continent spread throughout the Eurasian territory.

2. Expansion through Asia

In the easternmost regions of the Asian continent, the species of the Homo erectus managed to continue populating the continents and moreover, managed to survive for 2 million years on this continent.being the longest-lasting human species that has ever existed.

In Indonesia, more specifically on the island of Java, lived another hominid species, known by the name of Homo soloensis (Solo Valley Man), which was the species that managed to adapt to the climate and life in the tropics. Studies carried out on the remains of this species yielded data about its antiquity (between 40,000 and 60,000 years).

Humans managed to reach the island of Flores for the first time taking advantage of a time when the sea level had dropped considerably, which facilitated the access to the island.which facilitated the access to the island. But when the sea level rose again, many were trapped on the island due to the scarcity of resources there, with the larger members dying earlier because they needed more food.

Therefore, on that island the inhabitants who managed to survive were the smallest and the members of the following generations were even smaller (it is estimated that they were 1 meter tall and weighed less than 25 kg), They even formed a species called by the scientists as the Homo floresiensis. This species, in spite of being small, had a great capacity to create stone tools that could be used for hunting; however, they disappeared more than 50,000 years ago. On the other hand, the first Homo sapiens arrived in Southeast Asia between 50,000 and 70,000 years ago, so perhaps they came into contact with the floresiensis.

As far as the western territory of Asia is concerned, there are two theories about its settlement. One of them states that there was an interbreeding between the species that had just arrived from Africa and the one that lived there. The other theory says that the sapiens did not have offspring with the species that inhabited that territory when they arrived (the Neanderthals), so that according to this theory the sapiens ended up replacing all the predecessor human species without mixing with them. There are investigations that have revealed data in favor of both, so there is no one that is absolutely right.

It should be noted that in the area of Southern Siberia and also in China appeared some remains of Homo sapiens about 40,000 years old..

3. Expansion throughout Europe

Europe was inhabited by Neanderthals before Homo sapiensThe first humans were the first of these, expanding the settlement of the continents more than 500,000 years ago. However, they did not survive for as long as the Homo erectus that inhabited Asia.

The remains of Homo sapiens oldest remains that have turned up in Europe are about 45,000 years old.. In addition, remains 43,000 and 40,000 years old, respectively, were found in England and Romania. Curiously, our species arrived earlier to the islands of Southeast Asia than to the Iberian Peninsula, since the latter was only populated by sapiens 44,000 years ago.

4. Expansion into Australia

It is estimated that 45,000 years ago humans managed to cross the open sea until they managed to land in the territory known today as Australia.The first of these was a territory that until then had never been trodden by the human species, thus continuing with the populating of the continents. In the period from 70,000 years ago to 30,000 years ago, man made great discoveries (invention of the boat, bows and arrows, oil lamps and needles with which they were able to sew clothes that they kept warm). The first jewelry and the first drawings also date from this period.

That stage constituted a cognitive revolution in which new ways of communicating and thinking emerged. There is a well-validated theory that states that it is at this stage that the human brain developed numerous internal connections that facilitated a way of thinking more complex than any other to date, which allowed humans to communicate through a kind of language that was completely innovative, despite the fact that there was already a kind of language among humans.

This language not only allowed to warn other members when they saw a "dangerous" animal approaching, but also facilitated the sharing of information about other humans, and thus transmitting to other members that someone in the group might be dangerous.This hypothesis is known as the "gossip theory".

Other great advances produced thanks to the cognitive revolution were the following: the ability to transmit to other humans a greater amount of information about the surrounding environment, to plan and carry out actions of greater complexity, to form groups with a greater number of members and that at the same time are more cohesive.

5. Expansion throughout the Americas

Among the scientific community, the hypothesis has been widely accepted that humans gained access to the American continent through the Bering Strait, with a length of 82 km, which linked Asia and America in winter, through a layer of ice that formed.The Bering Strait, with a length of 82 km, joined Asia and America in winter through a layer of ice that formed, so that humans were able to cross it and thus access a new continent for the first time in its history about 12,000 years ago (late settlement theory), thus completing the settlement of the habitable continents.

However, there is another theory that states that humans had managed to reach the American continent earlier based on a series of archaeological findings (early settlement theory).