Neanderthal is one of the few hominin species we (Homo sapiens) lived together with. Although they are extinct, science suggests them to be our closest relatives.
But the Neanderthal’s story became interesting when Svante Paabo won the Nobel Prize in physiology and medicine for sequencing the Neanderthal’s DNA in 2022. Only after this, interesting stories, genetic insights and many more things came into the picture.
This article is all about the 5 latest, interesting and scientifically backed Neanderthal DNA research. You will find the references for each research covered here at the end of the article.
Stay tuned.
Key Topics:
We have neanderthal DNA, but how much?
Can you believe we still have some of Neanderthal DNA in us? Let’s begin our story with the latest research, showing that the modern human genome carries Neanderthal DNA, thereby revealing our evolutionary past!
What scientists did was they analysed large-scale genomic data from diverse human populations and compared it with Neanderthal DNA sequences.
The observations were surprising; the non-Africans still carry around 1-2% Neanderthal DNA; however, the distribution is not uniform. For instance, DNA traces linked to immunity, metabolism and skin are still present, while DNA traces for reproduction or brain functioning are lost.
The genes that were lost during the course of evolution, are believed to be harmful for survival.
So, what does this study say? This study shows that our genome adapts to a greater extent in order for our survival. It acts like a filter, like in this case, our genome kept the helpful pieces of neanderthal DNA while discarding the harmful ones.
This also means that human evolution is not just shaped by genetic mutations but also by the selective retention and rejection of genes, genes that were inherited from our ancestors.
The short but lasting interaction between humans and neanderthals
There is new evidence that reveals humans’ and neanderthals’ interaction was much shorter than once believed. Scientists studied dozens of ancient genomes and compared them to modern DNA and traced that the mixing began around 47,000 years ago and lasted for about 6,800 years.
If we see it on an evolutionary timescale, this time period is just like the blink of an eye, and yet it left behind DNA fragments still present in almost every non-African person alive today.
Surprisingly, as we already know, evolution did not keep much from this human – neanderthal encounter.
Researchers even found that traces of Neanderthal DNA completely vanished in the large stretches of the human genome, called Neanderthal deserts, even in some of the ancient human genomes.
This again suggests that many of those sequences were not favorable for survival in the process of natural selection; they were lost, and only those that were beneficial remained in our genome.
This study proves that though the interaction was short but still this short lived connection shaped our survival.
The Antibiotic Resistance in the Neanderthal Microbiome
Researchers discovered that genes linked to antimicrobial resistance were already present tens of thousands of years ago. Unbelievable right? Because obviously, it was even longer before the modern overuse of antibiotics.
But this study claims it.
After investigating the oral microbiome of neanderthals, which was reconstructed from ancient dental calculus samples. These resistance genes were found in microbial DNA fragments that were preserved in Neanderthal remains. This highlights that resistance is a natural, ancient feature of microbial evolution and not a pure modern-day problem.
The interesting part is that it is now believed that Neanderthals coexisted with microbial communities that had already developed ways to withstand the naturally occurring antibiotics that were in the environment at that time.
Does this mean our ancestors carried and probably exchanged the resistant microbes? Yes, as this study suggests.
Neanderthal DNA and the immune system of modern humans
Neanderthal DNA still shapes our immunity! Yes, and this is the most fascinating area of research right now. The ancient DNA that we inherited isn’t some random fragments; some of them actually played some crucial roles in how humans respond to infections.
For instance, it is believed that some of the specific immune-related genes from Neanderthals were absorbed into the human genome. And these genes helped early humans adapt to the new pathogens they encountered when they migrated out of Africa.
The research highlights that certain parameters like innate immune receptors, antiviral responses, and inflammatory pathways are influenced by variants inherited from Neanderthal DNA, and these genetic contributions from our ancestors gave us an additional advantage against infections in a new environment.
However, this DNA that we get can be harmful too, as the present research suggests. Some of these inherited variants are associated with autoimmune diseases, allergies, and chronic inflammation.
And we already know allergies are genetic.
So basically, Neanderthal DNA didn’t just survive in us; it also shaped our immunity. These variants are believed to play a role in how we fight infections, and on the other hand, can also sometimes make us more vulnerable to modern health problems.
Neanderthal DNA and modern diseases
Now we know, we have a small but substantial amount of neanderthal DNA.
About half a million years ago, Neanderthals and modern humans diverged, and yet their stories were reconnected 60,000 to 70,000 years ago when these two species met and interbred. This interaction left a lasting genetic footprint.
Genome-wide association studies have shown that the Neanderthal derived genetic variants, particularly single-nucleotide polymorphisms (SNPs), are linked to modern diseases.
Research on over 2,12,000 individuals from the biobank Japan project highlights that these SNPs are connected to diseases such as type 2 diabetes, liver cancer, lupus and even COVID-19 outcomes. Although some of these mutations are silent, others may alter the protein function, which can increase disease risk.
What this research suggests is that while interbreeding helped our ancestors adapt, the neanderthal DNA we still carry might have the potential to predispose us to modern diseases.
Wrapping up:
That’s it!
This is a small piece of our evolutionary story. Scientists are still doing research around our ancient DNA to understand humans and other hominin interactions, why we survived and why other hominins could not.
Tools such as NGS, GWAS and microarray are revealing much deeper genomic information, which was not understood in the past.
Scientists believe that with the use of modern gene editing tools such as CRISPR-Cas9, one day we will be able to directly address and even edit out the harmful neanderthal linked mutations from our genome.
Resources:
Neanderthal Human baby Making by Ahmad Shammazadeh.
Gomathinayagam Sankaranarayanan, and Gothandam Kodiveri Muthukaliannan. “Exploring Antimicrobial Resistance Determinants in the Neanderthal Microbiome.” Microbiology Spectrum, vol. 12, no. 8, 25 June 2024, https://doi.org/10.1128/spectrum.02662-23.
Patin, Etienne, and Lluis Quintana-Murci. “Tracing the Evolution of Human Immunity through Ancient DNA.” Annual Review of Immunology, 20 Dec. 2024, https://doi.org/10.1146/annurev-immunol-082323-024638.
Sümer, Arev P, et al. “Earliest Modern Human Genomes Constrain Timing of Neanderthal Admixture.” Nature, 12 Dec. 2024, https://doi.org/10.1038/s41586-024-08420-x.
The Drew Review, Drew University, May 2024, Volume 17.
