By Al Valente
The next time someone calls you a “Neanderthal”, don’t get upset because it just may be true – well, in part that is..
It turns out that if your ancestral lineage is from Europe then you most probably possess 1% to 2% Neanderthal genes. If you’re of Asian ancestral decent then, similarly, you have 1% to 5% of a different extinct hominin called “Denisovan”.
The reason we now know all this is attributed to Svante Pääbo, a Swedish geneticist at the Max Planck Institute for Evolutionary Anthropology. Pääbo laboriously determined how to extract and analyze DNA from 40,000-year-old Neanderthal bones. His decades of research have made it possible for scientists to begin probing differences between today’s modern humans and our ancient ancestors like Neanderthals and Denisovans.
The 2022 Nobel Prize in Medicine
This year’s 2022 noble prize in medicine was recently awarded to Dr. Pääbo for his creative work in isolating the Neanderthal genome from bone fragments found in Germany.
It was no small feat because such fragments are polluted with genes of microorganisms and the such, but Pääbo developed the means to isolate the actual Neanderthal mitochondria genes (mtDNA) in fragments and splice them together to ultimately sequence the entire genome.
His work went on to discover a previously unknown extinct hominin species when he extracted genes from a finger bone from the Denisova Cave in southern Siberia, the site that gave name to “Denisovans”
His work ultimately led to the initial sequencing of the Neanderthal genome about 10 years ago. With that, he could compare those unique Neanderthal genes that are now found in modern day humans which is roughly 1% to 2%.
We Were Not Alone
Currently, we Homo sapiens are the ultimate apex predictors on this planet, the king of the hill over all other species. But it wasn’t always this way, hundreds of thousands of years ago there were other hominins wandering major parts of earth. Two of interest were the Neanderthals and Denisovans who were erect bipeds, similar but not quite like us. They have both been extinct for about 30,000 years.
About 400,000 years ago Neanderthal species formed in the middle East and then migrated to what is now Europe. It wasn’t until about 70,000 years ago that Sapiens then migrated to Europe.
Hanky Panky among the Hominins
It turns out that the physical appearance between Sapiens and Neanderthals or Denisovans was close enough for them to interbreed. They coexisted for tens of thousands of years before the Neanderthals mysteriously died off. It was that interbreeding which imbedded extinct hominin genes into our modern-day DNA.
Your Odds of Having Ancient Hominin Genes
Although all that intermingling was tens of thousands of years ago, there remains a trace of ancient hominin genes in modern humans. If your ancestry is entirely from Africa then you are most likely fully Homo Sapien. If your ancestry is from Europe, you most likely have between 1% and 2% Neanderthal genes. If your ancestry is from Asia, you could have anywhere from 1% to 6% Denisovan genes.
O.K., How Does All This Affect Us?
Although a small percentage of our genes are comprised of ancient hominin genes, scientists believe it has subtly affected us. Genetic variants seem to have persisted within those intermingled groups primarily because they offered a survival advantage to people facing certain harsh environments and pathogens.
There were other adaptive advantages, for example Asians with the Denisovan genes are believed to be able to tolerate high altitudes which could explain the thriving populations in mountainous Tibet.
Unfortunately, there are some negative consequences. There is a correlation between having Neanderthal genes and premature births. But on the flip side, those same genes tend to have less miscarriages.
Those of us that suffer from severe allergies and credit some of that to the Neanderthal genes.
Enhanced Immunity
Researchers at the Max Planck Institute report about the discoveries in 2 independent studies confer the important role of past interspecies relations in human evolution and specifically in the evolution of the innate immune system, which serves as the body’s first line of defense against infection.
Newer studies highlight the functional importance of this inheritance on Toll-like receptor genes. These genes are expressed on the cell surface, where they detect and respond to components of bacteria, fungi, and parasites. These immune receptors are essential for eliciting inflammatory and anti-microbial responses and for activating an adaptive immune response.
If you think about it, the Neanderthals inhabited the western Eurasia for a good 200,000 years before Sapiens arrived. That was a good head start to develop immunity to indigenous bacteria, viruses and fungi some of that immunity ultimately got passed on to us.
Covid May be More Problematic
Paradoxically, although it is believed that the Neanderthal gene strengthens or immune system, sadly, humans with a specific Neanderthal gene variant that do catch Covid have been found to require extended hospitalization and ventilation treatment.
The DNA strand is found on chromosome 3, and a team of researchers in Europe has linked certain variations in this sequence with the risk of being more severely ill with Covid-19.
The Takeaway
What can you do about knowing you’re part Neanderthal? Not much really, you can’t change your genes especially that tiny portion of ancient genes you inherited. But you at least you can be aware of certain predispositions to Covid and take appropriate actions to play it safe.