Interbreeding Between Homo-Sapiens and Neanderthal Man

In the more recent prehistory of our species, specifically after we had left Africa around 70-50 ka, homo sapiens and Neanderthal species of human interbred with one another.

Today we share about 1-4% of our genome from our extinct Neanderthal cousins, in all populations (except those who are native to Africa — black people, who possess no Neanderthal DNA).

Scientists discovered the interbreeding of homo sapiens and Neanderthal in 2010 when the entire Neanderthal genome was sequenced. [1] Sequencing revealed that we share DNA — a relatively significant portion — between 1-4% of the genome, depending on the population.

Location of Contact

Scientists observed the geographical distribution of both species of humans at around the time that we know they would have been in contact (the period after our migration Out of Africa and before the Extinction of Neanderthal Man).

The location where our geographic distribution appears to overlap is the region of the Zagros Mountains — a north-south mountain range between the Fertile Crescent and the Iranian Plateau. Today it stretches along the modern borders of Iran, northern Iraq, and southeastern Turkey.

The region has a diverse range of biodiversity and geography, capable of supporting large, stable human populations. [1] In the dramatic climate change of the Late Pleistocene, it could have also acted as a corridor both east-west and north-south, from Africa to Asia and Africa to Europe. It also connected the cooler Palearctic Realm and warmer Afro tropical region. [1]

The Zagros Mountains region is rich in archaeological sites containing remains of prehistoric populations of both homo sapiens and Neanderthal.

This region was extremely important to civilizations of the early Holocene after the End of the Last Ice Age, the world’s first farmers and sedentary humans of the Neolithic, as well as to the first historic high civilizations of Sumer, Ancient Egypt, and Akkad. As it turns out, it was also important to earlier homo sapiens and sibling species of human as well, tens of thousands of years before.

Impact of Neanderthal Genome

These genes continue to effect many human physical traits, such as larger noses, lower pain thresholds, depression, and susceptibility to COVID-19. [1]

Resources

1. Hale, Tom. “We Finally Know Where Humans And Neanderthals Hooked Up”. IFL Science. 3 June 2025. <https://www.iflscience.com/we-finally-know-where-humans-and-neanderthals-hooked-up-79470>. Accessed 13 July 2025.