There are several theories about when and how humans came to populate America, but it is known that it could have been between 15,000 and 40,000 years
The first settlers of America, according to the most accepted theory, arrived through the Bering Strait, which is located between Siberia and Alaska. However, it is still under discussion.
Paleoanthropologists agree that modern humans left Africa between 70,000 and 85,000 years ago, arriving in America, the last continent to colonize, between 15,000 and 40,000 years ago.
How and from where did the first settlers arrive?
During the last ice age, which began 110,000 years ago and ended about 10,000 years ago, Asia and North America were linked by a wide strip of land, approximately 1,500 km wide.
Despite the glaciers and low temperatures, it allowed the passage of animals and human groups, at least twice, that in a few thousand years – it is not known for sure – advanced from Alaska to Tierra del Fuego.
However, despite advances in paleoanthropology and genetics, various theories continue to be proposed and debated about when and how they arrived, as well as whether it was one or more migratory waves, and whether they were all through Alaska.
On the other hand, studies carried out in the field of genetics have confirmed theories from the middle of the last century that proposed as the starting point of the first migrations to America, Mongolia and Siberia.
After the passage of the different migratory waves and the end of the glaciation, the communication through Bering was once again covered by water. Although communication between the Eskimos of Asia and America was maintained, the rest of the American settlers were isolated from the rest of the world for several thousand years, with just a couple of exceptions (the Vikings in the 10th century and contacts with Polynesians in the XII century).
Main theories of settlement
Theory of late settlement (Clovis consensus)
The late settlement theory, also called the Clovis consensus, was the dominant theory for most of the last century, and continues to have support today, although it has lost ground to the early settlement theory.
It is called the Clovis consensus, because it was in this archaeological site, in 1929, in New Mexico (United States), where the theories were confirmed that the first Americans arrived from Asia much earlier than previously thought, estimating between 14,000 and 16,000 years before.
In the following years, it was postulated that humans would have entered America through Alaska and crossed Canada through an ice-free corridor, and then continued their journey to Tierra del Fuego, in a migratory process that could have taken less than 5,000 years.
According to this theory, the members of the Clovis culture would be part of these first settlers, and from there the rest of the American peoples would descend.
One or three waves of migration
Another topic of discussion is whether there was more than one wave of migration from Asia. Supporters of a single wave suggest that it would have come out of Mongolia and northern China.
On the other hand, those who speak of a triple wave, such as the anthropologist and linguist Joseph Greenberg, propose a first entry 12,000 years ago (the Amerindians), the next about 8,000 years ago (the Na-Dene, to which peoples such as the Apaches and Navajos), and the Eskimo-Aleuts 6,000 years ago.
Early settlement theory
In the last years of the 20th century, the Clovis consensus began to be questioned by various researchers. This was due in part to studies that proved that the ice-free corridor through Canada arose when human settlements already existed in New Mexico. And on the other hand, to the discovery of human settlements as old or older than Clovis, in Mexico, Central and South America.
The antiquity of archaeological sites such as Monte Verde, in Chilean Patagonia, or Pedra Furada in Piauí (Brazil), has been estimated at more than 14,800 years, which forces us to think of a date of entry to America greater than 20,000 years.
These and other archaeological sites throughout the continent, such as the Chiquihuite cave in Mexico, seem to confirm that Clovis is not the oldest American culture, and that the date of entry of the first humans could be between 25,000 and 40,000 years earlier. of our era.
Regarding the route of entry, it is currently proposed that human groups moved along the coast, avoiding the great masses of ice that covered Canada, and very far from the current Bering Strait.
Theory of South America as the first route
The fact that there are more archaeological sites in South America than in North America, as well as some unexpected results in the field of genetic research (indigenous groups of the Brazilian Amazon genetically linked with groups of the Andaman Islands and Papua New Guinea), has revived an old migration theory, known as the Australian theory.
Its author, the Portuguese researcher António Mendes Correia, proposed in 1928 as a possible route for the occupation of South America, a road from Australia, bordering the coast of Antarctica and entering America through Patagonia.
Other theories have been proposed about the arrival of humans in America, based on the data provided by genetic research and the discovery of new archaeological sites.
Genetic research has revealed interesting data, such as that of the Brazilian tribes related to Papua New Guinea, or that of a Colombian tribe genetically related to inhabitants of Easter Island and the Marquesas Islands, in Polynesia.
There are researchers, such as the Brazilians Maria da Conceição Beltrão, Jacques Abulafia Danon and Francisco Antônio de Moraes Accioli Doria, who, based on excavations carried out in Brazil, even propose that current humans would not be the first in America, but rather groups of Homo erectus makes about 200,000 years or more.
In this case, there is a debate around the pieces exhibited as evidence found in the Toca da Esperança site, Brazil: if they are works carved by humans or are they objects carved by nature.
The theories and discussions about the first inhabitants of America are still on the table, but it is already certain that human beings arrived in America more than 15,000 years ago.
Rey, D., Areces, C. et al (2011). The first settlers of America and their relationships with populations in the Pacific Ocean according to the HL genes. Taken from elservier.es.
Pringles, H. (2012). The First Americans. Taken from scientificamerican.com.
Sáez, C. (2018). The first settlers of America colonized the continent in record time. Taken fromvanaguardia.com.
Zimmer, C. (2020). The Polynesia-South America connection: DNA study suggests ancient kinship. Taken from nytimes.com.
Herrero, A. (2020). The mystery of the first inhabitants of America: they arrived 15,000 years earlier than previously believed. Taken from elmundo.es.
Population of America (2021). Taken from es.wikipedia.org.