Why did people appear in Africa and not on another continent?

Homo sapiens arose approximately 300 thousand years ago on the African continent. That is, if we could trace our entire ancestry, we would definitely find our roots in Africa. Our direct ancestor is Homo erectus, which lived on three continents: Africa, Europe and Asia, like its descendant H. heidelbergensis. From the latter, three species of hominids emerged in different parts of the world: Neanderthals appeared in Eurasia, Denisovans in Asia, and Homo sapiens in Africa. Our species, as is known, arose later than the other two. But why did this happen in Africa? Scientists have been looking for an answer to this question for a long time and have several hypotheses.

Why did people appear in Africa, and not on another continent. Africa is the homeland of all modern people. Photo.

Africa is the homeland of all modern people

How it came to be Homo Sapiens in Africa

To find out why people appeared in Africa, it is necessary to find out how this happened in the first place. Unfortunately, scientists still cannot answer many questions on this matter. According to a study that was conducted back in the 80s, the mitochondrial DNA of Homo Sapiens dates back to a single population in Africa that lived between 200,000 and 150,000 years ago. That is, according to this study, the ancestors of modern humans were only one population.

Mitochondrial DNA is a type of DNA that is passed down only through the maternal line and helps trace ancestry.

However, not all scientists agree with this version. In the early days of Homo sapiens, there were dozens of populations that lived in different parts of Africa, so they had to adapt to different ecosystems and environmental conditions. As we've covered before, a recent study found that at least two populations were ancestral to H. sapiens. Moreover, people from these populations lived separately from each other for thousands of years. However, at some point they did mix, resulting in one mixed population that became our species.

How Homo Sapiens arose in Africa. Modern humans appeared about 300 thousand years ago. Photo.

Modern people appeared about 300 thousand years ago

Why modern humans appeared in Africa

Brenna Henn, an employee of the University of California, one of the authors of the 2023 study, suggests that it was the features of the continent that caused the emergence of Homo Sapiens. Since Africa is very large, and as mentioned above, contains many different ecosystems, many populations arose, each of which was adapted to certain conditions. Simply put, genetic diversity has emerged across the continent. The mixing of a large number of populations eventually allowed our ancestors to evolve, resulting in modern humans.

Curtis Marean, professor of paleoanthropology and deputy director of the Institute of Human Origins at Arizona State University, believes that both versions have a right to exist, that is, both the origin of humans from one population and from many populations. Moreover, the latest version, in his opinion, looks more realistic. After all, the more genetic variations a species has, the higher the likelihood of its development.

Why modern humans appeared in Africa. Ice ages would have prevented modern humans from appearing in Eurasia. Photo.

Ice ages would have prevented modern humans from appearing in Eurasia

Why humans could not have appeared in Eurasia

Eurasia is also a gigantic territory, but why did Africa become the cradle of humanity? According to scientists, in addition to territory, a warm climate was also an important factor in the emergence of Homo sapiens. Ice ages occurred on Earth every 100 thousand years, so hominids in Eurasia would have been surrounded by ice and isolated from each other. In Africa, people had access to each other, which ensured the necessary gene flow for evolution.

True, people continued to acquire new genes even after they left Africa. Let us remember that our ancestors in Europe and Asia mixed with Neanderthals. In one recent study, scientists even found out when this first happened. Neanderthal genes allowed people to adapt to new conditions outside of Africa.

Why people could not have appeared in Eurasia. People arose in Africa, perhaps due to the mixing of a large number of genes from different populations. Photo.

In addition, it is known that in Asia some peoples mixed with the Denisovans. This also gave them certain advantages. As a result, having the largest set of genes, people were able to survive, unlike all other species.

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Finally, we note that all voiced versions are only hypotheses. There is no clear evidence yet. Scientists have yet to figure out exactly which populations evolved into modern humans, and what role language played in the mental development of our ancestors. We can only hope that future research will answer these questions.