What does DNA Testing Tell Us About Mankind's Early History?

Michael Anissimov
Michael Anissimov
Michael Anissimov
Michael Anissimov
DNA tests have revealed that the humans who went on to colonize Asia and Europe originated in East Africa.
DNA tests have revealed that the humans who went on to colonize Asia and Europe originated in East Africa.

Present-day mitochondrial DNA testing has given us a lot of valuable information about the early history of mankind. Its most important contribution has been verifying the Out-of-Africa theory, also known as the recent single origin hypothesis. The Out-of-Africa theory asserts that all humanity descends from one founding group that originated in East Africa, probably somewhere around modern-day Tanzania. Its main competitor, now largely dismissed, is the Multiple Origin theory, a group of related claims that mankind separately originated in different areas, from different pre-human apes, and subsequently interbred.

According to the Out-of-Africa theory, humankind is descended from one group that originated near modern-day Tanzania.
According to the Out-of-Africa theory, humankind is descended from one group that originated near modern-day Tanzania.

The kind of DNA testing used most frequently to study humanity's early origins is mtDNA testing, also known as mitochondrial DNA. Mitochondrial DNA consists of small bits of DNA found in the mitochondria (power plants) of cells. It is passed along matrilineally, meaning that you get your mtDNA from your mother. There is another type of DNA, Y-chromosomal DNA, that is passed down patrilineally. Different forms of DNA testing are associated with both. The reason why these two types of DNA are uniquely useful for studying early human migrations is that they are the only DNA that is not constantly reshuffled around due to genetic recombination.

The ancestors to all humans outside of Africa arrived about 50,000 years ago in Europe.
The ancestors to all humans outside of Africa arrived about 50,000 years ago in Europe.

The date that the common mtDNA ancestor of all living humans, known as "Mitochondrial Eve" was alive is given by DNA testing as about 140,000 years ago. This is not the most recent common ancestor of all humans, which lived much more recently, just 2,000 to 5,000 years ago, but the most recent common ancestor through the mtDNA line. By studying how DNA haplogroups branch off from Mitochondrial Eve by testing the mtDNA of thousands of people around the world, scientists can get an approximate picture of how early migration patterns went.

According to DNA testing, the first modern humans appeared roughly 140,000 years ago.
According to DNA testing, the first modern humans appeared roughly 140,000 years ago.

According to DNA testing, modern humans originated approximately 140,000 years ago in East Africa, where they lived exclusively for several tens of thousands of years. This corresponds to haplogroup L1. Between 84,000 and 107,000 years ago, humans spread out to the rest of Africa, giving rise to haplogroups L2 and L3, which went to the west and northeast respectively. Most modern African Americans are members of haplogroup L2.

The majority of present-day African Americans are members of haplogroup L2.
The majority of present-day African Americans are members of haplogroup L2.

About 72,000 years ago, a small group of haplogroup L3, probably numbering only 100-200 individuals, crossed the Red Sea into modern-day Yemen. These are the ancestors of all humans outside of Africa. They spread into Europe, Asia, and Australia, where they arrived about 50,000 years ago. About 12,000 years ago, a similar discrete migration occurred over the Bering land bridge into the Americas. This group are the direct ancestors of all modern-day natives of North and South America. Most recently, humans colonized the islands of the Pacific from jump-off points in Southeast Asia. Anthropological and archaeological evidence largely supports this view of early human migration.

Michael Anissimov
Michael Anissimov

Michael is a longtime AllTheScience contributor who specializes in topics relating to paleontology, physics, biology, astronomy, chemistry, and futurism. In addition to being an avid blogger, Michael is particularly passionate about stem cell research, regenerative medicine, and life extension therapies. He has also worked for the Methuselah Foundation, the Singularity Institute for Artificial Intelligence, and the Lifeboat Foundation.

Michael Anissimov
Michael Anissimov

Michael is a longtime AllTheScience contributor who specializes in topics relating to paleontology, physics, biology, astronomy, chemistry, and futurism. In addition to being an avid blogger, Michael is particularly passionate about stem cell research, regenerative medicine, and life extension therapies. He has also worked for the Methuselah Foundation, the Singularity Institute for Artificial Intelligence, and the Lifeboat Foundation.

Discussion Comments

anon278537

Considering that Neanderthal habitation even in Northern Europe has been dated to 120.000+ years back (e.g. the wolves' cave in Finland).

Now, this puts a little dent of any hope of having a collective "out-of-Africa" experience, doesn't it?

Add to this similar clear Chinese evidence for their parts, and the whole Africa theory can be put to rest.

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    • DNA tests have revealed that the humans who went on to colonize Asia and Europe originated in East Africa.
      By: pavalena
      DNA tests have revealed that the humans who went on to colonize Asia and Europe originated in East Africa.
    • According to the Out-of-Africa theory, humankind is descended from one group that originated near modern-day Tanzania.
      By: Photocreo Bednarek
      According to the Out-of-Africa theory, humankind is descended from one group that originated near modern-day Tanzania.
    • The ancestors to all humans outside of Africa arrived about 50,000 years ago in Europe.
      By: Ekler
      The ancestors to all humans outside of Africa arrived about 50,000 years ago in Europe.
    • According to DNA testing, the first modern humans appeared roughly 140,000 years ago.
      By: adimas
      According to DNA testing, the first modern humans appeared roughly 140,000 years ago.
    • The majority of present-day African Americans are members of haplogroup L2.
      By: spotmatikphoto
      The majority of present-day African Americans are members of haplogroup L2.
    • Not only does DNA testing tell us much about an individual, but it can also shed light on how mankind has evolved.
      By: angellodeco
      Not only does DNA testing tell us much about an individual, but it can also shed light on how mankind has evolved.
    • The DNA testing used most frequently to study humanity's early origins analyzes mitochondrial DNA.
      By: designua
      The DNA testing used most frequently to study humanity's early origins analyzes mitochondrial DNA.