They are still here

In short, Neanderthals may not have become extinct, but rather were absorbed into the modern human population during long-term interbreeding between the two species. This is one of the conclusions of the study, which found that Neanderthal DNA makes up 2.5% to 3.7% of modern human DNA.

This study highlights that what we think of as a separate Neanderthal lineage is actually more closely related to our ancestors.
– says Fernando Villanea, a population geneticist at the University of Colorado at Boulder.

Modern human populations and Neanderthal populations “have a long history of interbreeding,” he adds.

Neanderthals were among the closest extinct relatives of modern humans, with our lineages diverging around 500,000 years ago. More than a decade ago, scientists discovered that: Neanderthals mated with modern human ancestors from Africa.

We have always heard that modern human groups have 1% to 2% Neanderthal DNA in their genomes. But what about the presence of Homo sapiens DNA in the Neanderthals themselves?

Researchers know less about how modern human DNA might have entered the Neanderthal genome. This is largely because only three high-quality examples of complete Neanderthal genomes have survived to this day; samples from Vindija Cave in Croatia, which date to between 50,000 and 65,000 years ago, and samples from Čagirska and Denysova Caves, which date to about 80,000 and 50,000 years ago, respectively.

There is a wealth of research on how contacts between Neanderthals and modern humans have affected our DNA and evolutionary history, but we know much less about how these encounters affected Neanderthal genomes.
– says Joshua Aiki, a population geneticist at Princeton University in New Jersey and senior author of the study.

In the new study, the scientists relied on the fact that both modern humans and Neanderthals had two versions of each gene, one inherited from the father and one from the mother. This sets them apart from other species in the human lineage. Interbreeding between Neanderthals and humans would have resulted in offspring that were more likely to have two different versions of each gene, compared to children resulting from no such interbreeding. This is a condition known as heterozygosity.

Researchers compared the genomes of three Neanderthals with those of 2,000 modern humans. They found that Neanderthal genome may account for 2.5% to 3.7% of modern human DNAThis means that roughly 1 in 30 of modern humans’ ancestors were Neanderthals.

The team’s analysis showed that modern human DNA entered the Neanderthal genome during at least two different periods of interbreeding:

• One from about 200,000 – 250,000 years ago.
• Another from about 100,000 to 120,000 years ago.

Interbreeding may have occurred at other times, but such events may not have left any visible traces in the Neanderthal genome.

Scientists suggest that most of the Neanderthal DNA we see in the modern human genome is the result of Neanderthal DNA. A period of major hybridization began around 47,000 years ago.It took about 6,800 years. Interbreeding that occurred at other times, like the earlier events that affected the Neanderthal genome, likely left no visible trace in our genome.

The skulls, found in the Shul and Qafzeh caves in Israel, date to about 100,000 years ago, around the same time as one of the most significant interbreeding events identified in the study. Although these fossils appear to be remnants of modern humans, they still have relatively primitive features, such as larger eyebrows. “There may be signs of gene flow from Neanderthals”says Chris Stringer, a paleoanthropologist at the Natural History Museum in London who was not involved in the new study.

There were fewer Neanderthals overall

The new study, which analyzed the level of genetic diversity among three Neanderthal genomes, also found that the long-term population average of Neanderthals was about 20% smaller than previously thought.

This doesn’t seem like a huge difference, but considering that Neanderthals already had a fairly small population size, the fact that it was even smaller is an important discovery.
Added Joshua Aikie.

These new lower estimates of Neanderthal population size suggest that Neanderthals may have simply disappeared due to extinction. absorbed by modern human population. Periodic waves of modern human migration out of Africa eventually overwhelmed the ability of Neanderthals to remain a distinct population, and they were assimilated into the gene pool of the modern human population. Neanderthal parents died naturally, and their offspring, resulting from mating with Homo sapiens, acquired more and more of the genome and characteristics of modern humans. Thus, Homo neanderthalensis simply “dissolved” into Homo sapiens, leaving behind only a small percentage of their genes.