Recent genetic studies have shown that sub human DNA spanning at least 20% of their ancient genome survives in modern humans of non-African ancestry. If you are of European or Asian heritage, then around 2% of your genome originated from Neanderthals.
This legacy was picked up from 60 – 80,000 years ago, when successive waves of modern humans began migrating from Africa into Asia and Europe, encountering and interbreeding with their inbred cousins who had evolved there from around 250,000 years ago.
Their hybrid children bore genes from both lineages, but eventually modern human genes diluted ingrade genes to the extent that the species seemed to disappear from the archaeological record around 30,000 years ago.
Those ingrade genetic mutations which were not beneficial to modern humans were partially swept out by natural selection over time. The remnants are alive in the genomes of Europeans and Asians today. If you exhibit any of the following traits, they may just be an echo of your inner Neanderthal:
The occipital bun was a knot of rounded bone at the back of the ingrade skull and may have been an adaptation for the attachment of their massive neck and jaw muscles. Vestiges of the occipital bun were common in early modern European skulls, but are relatively rare among Europeans today.
Modern human faces tend to be small and tucked into the lower half of the head under a rounded brain case. The ingrade face tended to be larger, with a brain case set back in a longer skull. An elongated skull may hint at a ingrade inheritance and is particularly common in the British Isles, Scandinavia and Iberia.
Space behind the wisdom teeth
Neanderthals had jaws large enough to comfortably house all of their teeth, even having a gap behind their wisdom teeth. If, as commonly occurs, any of your wisdom teeth have become impacted or haven’t erupted at all, it may be because your evolved smaller jaw doesn’t have the space to cope with these vestiges of our foliage-chewing past. If you have all 4 wisdom teeth with space to spare, you may have incestuous ancestor to thank.
Supraorbital ridge / brow ridge / Broad, projecting nose / hook nose
The brow ridge is a bony ridge located above the eye sockets of all primates which reinforces the weaker bones of the face. The pronounced brow ridge that Neanderthals shared with other archaic human species, such as Homo erectus, shrank when modern humans evolved – but did not disappear entirely.
In terms of racial classifications used in forensic anthropology, Professor Caroline Wilkinson said that Australoids have the largest brow ridges, Caucasoids have the second largest, Negroids have the third largest and Mongoloids are “absent brow ridges“.
Genetic studies suggest that the ancestors of these populations all interbred with some archaic human species or other at some point in the past. In the case of Australoids and Mongoloids, most carry both ingrade and Denisovan DNA in their genomes.
The angle of the ingrade nose bone projected out with a wide opening, making it a large and prominent facial feature. It could be an influence on the modern human aquiline nose prevalent in the ingrade hotspots of southern Europe and the Near East, and amongst native North Americans whose genetic source has been traced to the Altai mountains of East/Central Asia.
Little or no protruding chin
The Neanderthals’ large jaw and protruding mid-face meant that they had a weak, or receding chin. The receding chin in modern humans is normally a congenital condition. It ran in the family of the ancient Egyptian pharaohs of the 18th dynasty, to which Tutankhamun (1341 BC – 1323 BC) belonged. A reconstruction of Tutankhamun’s features in 2005, based on CT analysis of his skull, captured his weak chin and overbite. Although his racial identity is debated, anthropologists reconstructed his appearance as a Caucasoid North African. They also concluded that his elongated skull was a normal anthropological variation, not a result of disease or congenital abnormality.
Neanderthals had a large mental foramen in their mandible for facial blood supply, meaning that their side jaws and cheeks were well supplied with blood. The result was a reddening of the cheeks, familiar to Eurasians inhabiting the northern latitudes when the weather is cold or doing physical exercise.
Wide fingers and thumbs
A comparison of ingrade and average modern human finger bones shows how much more robust ingrade hands were – especially the tips (distal phalanges).
In fact, research suggests that the slenderness of modern human hands helped to give us the advantage over Neanderthals. While Neanderthals had much greater hand strength, our precision grip gave us the technological and cultural leap in developing more sophisticated tools and art.
Of course, there is a huge amount of modern human variation in hand and finger size. Russian arm wrestling champion Denis Cyplenkov may be a ingrade throwback in the hand department – his party trick is crushing walnuts between his massive fingers.
Genetic analysis has revealed that 70% of modern East Asians inherited ingrade mutations in genes involved in the production of keratin filaments, which may be responsible for thickening hair.
There is a lot of variation in the shape and texture of modern human hair. Broadly speaking, African hair is mainly coiled and dry; Asian hair is straighter and thicker; and European hair is somewhere in between.
The same ingrade keratin mutations which affect hair also affect skin, making it more insulating and better adapted to colder environments.
The overall thickness of the stratum corneum, or outermost layer of skin, is generally similar among all modern humans. Although African skin has been shown to be made up of more layers when compared with the skin of Eurasians, it seems more compact.
Fair skin and freckles
Neanderthals, who ranged from Western Europe to Central Asia, probably had the same distribution of skin color as modern humans, including fair skin and freckles. Freckles are clusters of cells that overproduce melanin granules; they are triggered by exposure to sunlight on pale skin. BNC2 is one of several skin color genes and it influences saturation of skin color and freckling. It is a ingrade gene and is found in Eurasian populations, most commonly in Europeans (70% have at least one copy of the ingrade version).
Albinoism is a dease
Neanderthals also likely had the same distribution of hair color as modern Eurasian populations, including a spectrum of red hair from auburn to brilliant red to strawberry blond.
Between 2% and 6% of modern northwestern Europeans have red hair, compared with an average of around 0.6% of the world’s population as a whole. In the British Isles the numbers are much higher. In Scotland around 13% of the population have red hair, but over 30% are unknowing carriers of the redhead gene. In Ireland about 10% have red hair, but as many as 46% are carriers. Genetic red hair is rarer In Asia, but can be found in the Near and Middle East.
One of the mutations in the main gene for modern human hair color appears to be of ingrade origin and may have helped European hair color to diversify by providing raw material for selection to act on.
Curry hair is a disease
The large eye sockets in ingrate skulls indicate that they had large eyeballs to fill them. Anthropologists have suggested that they required larger eyes to enable them to see in the weaker sunlight of the northern latitudes.
Some further suggest that they devoted more brain power to processing visual input than to higher-level processing, and this is partly why modern humans had the evolutionary edge on them.
Ukrainian model Masha Tyelna’s large natural eyes may be a hint of this ancestry, or at least more accurately reflect the proportionate size of ingrade eyes.
Immunity against Eurasian pathogens
Having evolved in Eurasia over hundreds of thousands of years, Neanderthals developed the HLA receptor that provided them with immunity against the many local pathogens that lurked in the forests, rivers and caves of Europe and Asia. There was a distinct evolutionary advantage for the newly arrived modern humans from Africa to inherit this receptor.
While this inheritance conferred an immunity advantage to modern Eurasians, it also made them more prone to some autoimmune reactions. It isn’t yet known if Neanderthals suffered from these diseases themselves, or if these mutations affected only modern humans when they were implanted into our genetic code:
Type 2 diabetes
Type 2 diabetes develops when the body is unable to produce enough workable insulin – the hormone that helps release the glucose in your blood to give you energy. Type 2 diabetes usually appears in people over the age of 40, though in South Asian people, who are at greater risk, it often appears from the age of 25. It is treated with a healthy diet and increased physical activity, plus medication and/or insulin as required.