8 Neanderthal Traits in Modern Humans

Updated on November 30, 2018
leahlefler profile image

After having obtained a degree in biochemistry, Leah works for a small biotechnology company and enjoys writing about science.

Neanderthal genetic variants have been isolated in modern day humans, indicating humans intermarried with the ancient population.
Neanderthal genetic variants have been isolated in modern day humans, indicating humans intermarried with the ancient population. | Source

Neanderthal Genes Influencing Human Traits

No one knows precisely why Neanderthals died out 40,000 years ago, but we do know there was some intermarriage between their community and our ancestors. Many of these genes have been purged from the modern human population over time due to natural selection, so the current prevalence is only 1-4% of the current human genome. While the prevalence of genes from Neanderthals are rare in humans (<2% in non-African populations), these genes still contribute to different physical characteristics. The inherited traits from the Neanderthal population sometimes offer benefit, and sometimes are linked to disease causing traits. The vast majority of the identified genes remaining in the non-African population are associated with hair and skin color. Genes with a Neanderthal origin are called archaic genes.

When humans and Neanderthals coexisted, up to 10% of the human genome was comprised of Neanderthal genes.

A common question arising from the intermarriage of humans and Neanderthals is the question of fertility among the offspring of these unions. The evidence (Sankararaman, S. et. al., 2016) indicates that the hybrid children were less fertile, as the prevalence of Neanderthal genes on the X chromosome are fewer than those found on the autosomal (non-sex) chromosomes. This finding is due to natural selection, which suggests the Neanderthal genes on this chromosome impaired fertility and have reduced over time as the X chromosomes with more human genes produced more fertile males.

In general, genes which conferred benefit to the human population remained, and genes which caused harm were eliminated over the course of time.

Neanderthal Range in Europe and Asia

Neanderthals inhabited Europe (blue), the Altai mountains (purple), Uzbekistan (green), and Asia (orange) at the same time humans were migrating out of Africa.
Neanderthals inhabited Europe (blue), the Altai mountains (purple), Uzbekistan (green), and Asia (orange) at the same time humans were migrating out of Africa. | Source

How Do We Know Which Genes Come from Neanderthals?

The genomes of several Neanderthals have been fully sequenced, allowing for researchers to compare the genomes of modern day humans alongside the archaic genes. In addition, researchers compare the genomes of people from sub-Saharan Africa, which contain absolutely no archaic genes as this population never existed in Africa. Since human population migrated out of Africa, once hybridization occurred the population spread outward to Europe and Asia. Human populations in Europe, Asia, and Oceana contain the highest percentage of archaic genes (though this is still a small percentage).

Alleles are variant forms of a gene that are found on the same location on a chromosome.

By comparing the genomes which contain no traces of Neanderthal genes, the fully sequenced archaic genomes, and the genetics of modern day Europeans , scientists are able to piece together which genes are derived from a Neanderthal ancestor.

A comparison of a modern human skull with a Neanderthal skull. Note the prominent brow ridge and nasal bone projection in the Neanderthal skull.
A comparison of a modern human skull with a Neanderthal skull. Note the prominent brow ridge and nasal bone projection in the Neanderthal skull. | Source

Selected Genetic Alterations from Archaic Genes

Physical Characteristic
Genes Affected by Neanderthal Alleles
Tendency to have blood clots (DVT)
SELP
Protein-Calorie Malnutrition
SLC35F3
Eye Color
OCA2
Mood Disorders/Addiction
CDH6, SLC6A11
Delayed Sleep Period
ASB1, EXOC6
Skin Disorders
BNC2
Several single nucleotide polymorphisms (SNP's) from the Neanderthal population affect the functionality of genes in the human genome.

Did Red Hair Come from Neanderthals?

A common urban myth states that red hair in humans comes from Neanderthals. Humans in today’s world generally have mutations on the melanocortin (MC1R) gene that cause an over-production of pheomelanin, which produces a red hair color. A second theory is that a separate gene that reduces the functionality of the MC1R gene is from Neanderthals (p.Arg307Gly), but none of these mutations have been observed in the fully sequenced genomes from two Neanderthals. In short, those with ginger hair in today’s world do not appear to have inherited the trait from Neanderthals.

1. Hair Color and Type

Several overlapping genes for both the human and Neanderthal population are linked to both blonde and dark hair. It appears that Neanderthals were as varied in skin tone and hair tone as modern day humans and it is impossible to identify the presence of an archaic genome by observing a current human’s hair or skin color. The formation of hair, which largely involves the production of keratin, is influenced by archaic genes. Two primary conditions remain in humans from our Neanderthal ancestors:

  • Actinic Keratosis is caused by damage from exposure to ultraviolet light. This is a pre-cancerous condition and causes scaly bumps on a person’s skin surface. If left untreated, this skin lesion may develop into Squamous Cell Carcinoma.
  • Seborrheic Keratosis are completely harmless skin growths that can range in color from tan to black. These growths are sometimes referred to as “barnacles.”

2. Immune System Benefits

Over 31 genes involved with the immune system in modern day humans are derived from an archaic ancestry. The continued existence of these genes indicates they are beneficial and protective against different forms of infection. Specific mutations that help defeat viral infections are present in both populations. The OAS1, OAS2, and OAS3 genetic changes inherited from the Neanderthals increase the activity of the anti-viral genes, which helps humans overcome contagious diseases.

Another inherited genetic mutation is called the TLR1/6/10 haplotype. This variation is found in the highest concentration in East Asia, and confers resistance to H. pylori and stomach ulcers. People who have this variant may also be more prone to allergies.

3. The “Night Owl” Sleeping Pattern

Genetic variants on ASB1 and EXOC6 are archaic genes that are associated with a preference for staying up late and napping during the daytime hours. The concentration of these genes increases in direct correlation to distance from the equator. The northern latitudes experience a greater shift in the day length, which affects circadian rhythm. The ASB1 and EXOC6 variants may confer a benefit to those who live in northern climates with short day-length cycles in the winter.

Light is detected by the eyes and transmitted to the suprachiasmatic nuclei (SCN), which inhibits the production of  melatonin during the day. Night owls have a delayed onset of melatonin production when light dims, delaying the sleep cycle.
Light is detected by the eyes and transmitted to the suprachiasmatic nuclei (SCN), which inhibits the production of melatonin during the day. Night owls have a delayed onset of melatonin production when light dims, delaying the sleep cycle. | Source

4. A Tendency for Depression from Archaic Genes

The same genetic inheritance regarding circadian rhythms is also associated with an increased level of chronic depression. Lack of sunlight is a known cause of depression among humans living in northern latitudes, and the prevalence of some of the mutations increases the farther a population is from the equator. Neanderthal alleles near the CDH6 gene are associated with an increased frequency of feeling unenthused and apathetic.

Addiction to substances such as tobacco is also influenced by these genes. While prevalent in less than 0.5% of the European population, one variant on the SLC6A11 gene increases the likelihood for addiction and is a positive predictor of smoking behavior.

5. Blood Clotting Issues and Deep Vein Thrombosis

In the European population, approximately 6.5% of people have a mutation on the SELP gene that increases a tendency to form blood clots. This gene is responsible for a protein that adheres cells and platelets to wound areas and to inflamed blood vessels.

Another archaic variant is for a gene encoding the Factor V protein. This mutation is separate from the most common genetic cause of blood clots in Europeans (Factor V Leiden). Those who have the rs3917862 allele have an increased rate of having thrombosis. When a person has both the Factor V Leiden mutation and the Neanderthal derived mutation, the risk of having a deep vein thrombosis is increased to a higher level than observed with the Factor V Leiden mutation alone.

Some archaic alleles contribute to a tendency to form blood clots easily. This can lead to problems with deep vein thrombosis in some individuals.
Some archaic alleles contribute to a tendency to form blood clots easily. This can lead to problems with deep vein thrombosis in some individuals. | Source

6. Protein-Calorie Malnutrition

Neanderthals age a diet high in protein and low in carbohydrates. Thiamine is a nutrient primarily found in beef, liver, eggs, and other protein-rich foods. One archaic allele on SLC35F3 produces a thiamine transporting protein. This activity of the transporting protein was reduced in Neanderthals, who ate a diet highly rich in the nutrient. The presence of the archaic mutation can increase the chance of malnutrition, as the amount of thiamine (vitamin B1) available to the body is reduced for those who consume a diet high in refined carbohydrates. Unfortunately, since modern refinement practices reduce the amount of thiamine available in grains to begin with, humans with this mutation may be at a risk of this deficiency, also known as “beriberi.” This condition is known as “high calorie malnutrition,” as the person is obtaining enough calories, but is not getting enough of a particular nutrient for body functions to work correctly. Thiamine Deficiency can cause dysautonomia, including Postural Orthostatic Tachycardia Syndrome, or POTS. Other disorders including psychiatric disorders, swelling of the legs, vomiting, and heart failure can be caused by a vitamin B1 deficiency.

7. Eye Color

The OCA2 gene is responsible for producing hair, skin, and eye color. While people originating from Africa have over 74 genetic differences from the Neanderthal sequence for this gene, those from non-African locations only demonstrate a little over 10 differences from the archaic genome. This indicates a rather recent influx of Neanderthal genes into the human population that migrated out of Africa. One mutation that is consistent between the Neanderthals and modern-day humans is a mutation on OCA2 that produces a blue eye color. The origin of blue eye color, however, does not arise solely due to the presence of archaic genes. Modern-day humans also have mutations causing a blue eye color that are not present in the Neanderthals, so the origin of blue eyes is likely due to a multitude of factors.

8. Both Light and Dark Skin Inherited from Neanderthals

Both light and dark skin tones are observed in inheritance from the Neanderthal population. This indicates that this group had variation in skin tone, similar to modern humans.

Some alleles on the BNC2 gene are archaic and are derived from the Neanderthal population. This genetic variation causes an increased susceptibility to sunburn and is present in up to 66% of the European population. In addition to increasing the risk for sunburn, this variant causes skin lesions due to keratosis. This gene is responsible for a lighter skin tone and increased ability to process Vitamin D in low-sunlight conditions. These genetic mutations also cause an increase in susceptibility to skin cancer.

Interestingly, a smaller proportion of Europeans inherited darker skin from the Neanderthals. A gene located close to the BNC2 gene is associated with increased pigmentation in the skin. Up to 19% of the identified overlapping human-Neanderthal genes are associated with this second allele that produces darker skin.

Neanderthals had a wide range of hair and skin tone. While an urban legend often states red hair is from Neanderthals, the modern human mutation for red hair is not observed in the Neanderthal genome.
Neanderthals had a wide range of hair and skin tone. While an urban legend often states red hair is from Neanderthals, the modern human mutation for red hair is not observed in the Neanderthal genome. | Source

Sources

Dannemann, M. & Kelso, J. (2017). The Contribution of Neanderthals to Phenotypic Variation in Modern Humans. The American Journal of Human Genetics, Volume 101, pp. 578-579.

Harris, K. & Neislen, R. (2016). The Genetic Cost of Neanderthal Introgression. Genetics, Volume 203, pp. 881-891.

Sankararaman, S., Swapan, M., Patterson, N., & Reich, D. (2016). The Combined Landscape of Denisovan and Neanderthal Ancestry in Present-Day Humans. Current Biology, Volume 26, pp. 1241-1247.

Gittelman, R., Schraiber, J., Vernot, B., Mikacenic, C., Wurfel, M., Akey, J. (2016). Archaic Hominem Admixture Facilitated Adaptation of Out-of-Africa Environments. Current Biology, Volume 26, pp. 3375-3382.

Simonti, C. et. al. (2014). The Phenotypic Legacy of Admixture Between Modern Humans and Neandertals. Science, Volume 343, pp. 737-741.

Questions & Answers

    © 2018 Leah Lefler

    Comments

      0 of 8192 characters used
      Post Comment

      • leahlefler profile imageAUTHOR

        Leah Lefler 

        5 days ago from Western New York

        Thanks, Dianna. It is quite fascinating there is a genetic legacy from the intermarriage of humans and Neanderthals. Most of the genes that would cause damage to humans have been selected against over time, leaving mostly beneficial genes. There are some genes that are still potentially harmful, though, including those that increase inflammation risk and the risk of having blood clots.

      • teaches12345 profile image

        Dianna Mendez 

        6 days ago

        This certainly opened by eyes to the history of Neanderthals. What an interesting topic to write on and you covered it so well.

      working

      This website uses cookies

      As a user in the EEA, your approval is needed on a few things. To provide a better website experience, owlcation.com uses cookies (and other similar technologies) and may collect, process, and share personal data. Please choose which areas of our service you consent to our doing so.

      For more information on managing or withdrawing consents and how we handle data, visit our Privacy Policy at: https://owlcation.com/privacy-policy#gdpr

      Show Details
      Necessary
      HubPages Device IDThis is used to identify particular browsers or devices when the access the service, and is used for security reasons.
      LoginThis is necessary to sign in to the HubPages Service.
      Google RecaptchaThis is used to prevent bots and spam. (Privacy Policy)
      AkismetThis is used to detect comment spam. (Privacy Policy)
      HubPages Google AnalyticsThis is used to provide data on traffic to our website, all personally identifyable data is anonymized. (Privacy Policy)
      HubPages Traffic PixelThis is used to collect data on traffic to articles and other pages on our site. Unless you are signed in to a HubPages account, all personally identifiable information is anonymized.
      Amazon Web ServicesThis is a cloud services platform that we used to host our service. (Privacy Policy)
      CloudflareThis is a cloud CDN service that we use to efficiently deliver files required for our service to operate such as javascript, cascading style sheets, images, and videos. (Privacy Policy)
      Google Hosted LibrariesJavascript software libraries such as jQuery are loaded at endpoints on the googleapis.com or gstatic.com domains, for performance and efficiency reasons. (Privacy Policy)
      Features
      Google Custom SearchThis is feature allows you to search the site. (Privacy Policy)
      Google MapsSome articles have Google Maps embedded in them. (Privacy Policy)
      Google ChartsThis is used to display charts and graphs on articles and the author center. (Privacy Policy)
      Google AdSense Host APIThis service allows you to sign up for or associate a Google AdSense account with HubPages, so that you can earn money from ads on your articles. No data is shared unless you engage with this feature. (Privacy Policy)
      Google YouTubeSome articles have YouTube videos embedded in them. (Privacy Policy)
      VimeoSome articles have Vimeo videos embedded in them. (Privacy Policy)
      PaypalThis is used for a registered author who enrolls in the HubPages Earnings program and requests to be paid via PayPal. No data is shared with Paypal unless you engage with this feature. (Privacy Policy)
      Facebook LoginYou can use this to streamline signing up for, or signing in to your Hubpages account. No data is shared with Facebook unless you engage with this feature. (Privacy Policy)
      MavenThis supports the Maven widget and search functionality. (Privacy Policy)
      Marketing
      Google AdSenseThis is an ad network. (Privacy Policy)
      Google DoubleClickGoogle provides ad serving technology and runs an ad network. (Privacy Policy)
      Index ExchangeThis is an ad network. (Privacy Policy)
      SovrnThis is an ad network. (Privacy Policy)
      Facebook AdsThis is an ad network. (Privacy Policy)
      Amazon Unified Ad MarketplaceThis is an ad network. (Privacy Policy)
      AppNexusThis is an ad network. (Privacy Policy)
      OpenxThis is an ad network. (Privacy Policy)
      Rubicon ProjectThis is an ad network. (Privacy Policy)
      TripleLiftThis is an ad network. (Privacy Policy)
      Say MediaWe partner with Say Media to deliver ad campaigns on our sites. (Privacy Policy)
      Remarketing PixelsWe may use remarketing pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to advertise the HubPages Service to people that have visited our sites.
      Conversion Tracking PixelsWe may use conversion tracking pixels from advertising networks such as Google AdWords, Bing Ads, and Facebook in order to identify when an advertisement has successfully resulted in the desired action, such as signing up for the HubPages Service or publishing an article on the HubPages Service.
      Statistics
      Author Google AnalyticsThis is used to provide traffic data and reports to the authors of articles on the HubPages Service. (Privacy Policy)
      ComscoreComScore is a media measurement and analytics company providing marketing data and analytics to enterprises, media and advertising agencies, and publishers. Non-consent will result in ComScore only processing obfuscated personal data. (Privacy Policy)
      Amazon Tracking PixelSome articles display amazon products as part of the Amazon Affiliate program, this pixel provides traffic statistics for those products (Privacy Policy)