(Author: Eric Malikyte)
Humans, as we know them today, have only been on this Earth for a couple hundred thousand years. Before our rise as Homo sapiens to spot of undisputed apex predator of the planet, there were several competing species living in Europe, each of them attempting to make a go of life on this insignificant mudball.
We know of several species of early humans such as homo Erectus, homo ergaster, as well as Neanderthals, but at least in the European region, it’s been something of a mystery how modern human DNA managed to penetrate into Neanderthal communities.
Well, today, Israeli archaeologists believe they have discovered a potential solution to that question.
A Brief History of Homo
The story of humanity is written in our very genome (and it features more death and destruction than a Stephen King novel), and while it’s generally undisputed that humans evolved from a shared ancestor of both humans and chimpanzees, the more recent years of our history have been more hotly contested among archaeological circles.
Our genome looks the way it does because of our ancestors getting it on…as well as other genetic interactions…
Homo sapien in Latin means “wise man,” and our species was named by Carl Linnaeus in 1758 (and seriously if only he could see us now).
Our species is the only surviving one from the genus homo. Modern humans first showed up in Africa, most likely within the past 200,000 years (as we explained in the intro), and are thought to have evolved from Homo erectus.
Scientists have used two competing models to explain how humans have evolved since first showing up in Africa. One model assumes that humans came from Africa, and the other one is more multi-regional, assuming that humans evolved all over the planet over a long period of time.
However, evidence like genetic studies seems to support the idea that we migrated out of Africa, with the highest levels of genetic variation in humans being found there.
And believe it or not, there is more genetic diversity in Africa than the rest of the world…combined.
In fact, our DNA and its origin has been traced all the way back to just one African woman. A woman who lived between 50,000 and 500,000 years ago who we call “mitochondrial eve.”
While our genomes are a combination of our mother and father’s DNA, mitochondrial DNA comes solely from the mother in our species. This is because female eggs contain large amounts of mitochondrial DNA, whereas sperm in males really doesn’t have much of it at all.
To add insult to injury here, sperm actually uses that small amount of mitochondria to power their sprint to fertilize that female egg, and once the sperm’s done its thing, the mitochondria are annihilated.
So, mitochondrial DNA comes from women.
And your mitochondrial DNA is identical to your mother’s and her mother’s.
This form of DNA is like gold to evolutionary biologists, except there’s an abundance of it thanks to the fact that there are typically plenty of copies (which makes it totally different from gold I guess), and it’s way easier to extract than DNA found in the nucleus.
But it’s more than a little silly to assume that Mitochondrial Eve was the first or only woman on Earth, and she definitely wasn’t, however, what she does represents is the point from which all modern generations of humans appear to have grown from.
Evolutionary biologists think that this is because of what’s known as an evolutionary “bottleneck” that occurred during Eve’s lifetime. Meaning that this is the time when a majority of our species died out, leaving very few survivors, probably due to some kind of extinction event similar to that one we talked about that happened 40,000 years ago).
On the flipside of this, DNA from the Y chromosome is only passed on from males to their male offspring. In fact, the evolutionary tree relating to all present-day males also supports this African migration model.
Human skulls also offer plenty of support to this model. Scientists found that as we move further and further away from Africa, populations are less varied in their genetic makeup. They found this after studying the skull measurements and genetics in 53 different human populations around the planet.
The most likely explanation for this is that human populations probably shrank as they spread out from Africa, so genetic diversity in those populations were greatly reduced.
It’s for this reason that scientists think that humans most likely originated from one place, rather than multiple regions.
However, moving out of Africa was not an easy task, as many populations found themselves courting extinction.
The first wave of humans moving out of Africa found more resistance than a bad Organ Trail playthrough, as many of them didn’t succeed in escaping Africa.
In fact, at certain periods of time their numbers appear to have dwindled to as few as 10,000.
Mount Toba, a supervolcano in Sumatra, erupted some 70,000 years ago, leading to a potential nuclear winter that is thought to have trigged a thousand-year-long ice age.
This is thought to have put some pressure on early humans traveling out of Africa to cooperate with each other, to the extent that they started favoring close family connections or the forming of tribes.
But between 50,0000 and 80,000 years ago another wave of humans migrated out of Africa that could be considered very similar to us, at least in terms of behavior and physical characteristics. And it’s thought that they were largely successful in navigating that perilous journey because of a newfound cooperative nature.
However, separate from this history is that of homo neanderthalis, or Neanderthals as you and I know them.
This species is extinct today, but a few of you watching may actually have a percentage of Neanderthal DNA.
Neanderthals lived in ice-age Europe as well as Western Asia between 28,000 and 250,000 years ago. You’re probably pretty familiar with their depiction: a receding forehead and prominent brow ridges (many of us in the Dragon Ball fandom know this as the “caveman” look.)
The first Neaderthal fossil was discovered in 1856, in the Neander Valley near Dusseldorf, Germany.
Since that first discovery, researchers have been scrambling to uncover how Homo neanderthals fits into the overall picture of modern human evolution because they just disappear from the fossil record about 28,000 years ago.
Now, their vanishing is usually attributed to competition between modern humans who were traveling out of Africa about 125,000 years ago (competition being a replacement word for murder), but there are a few theorists who suggest that there may have been a brief period of co-existence.
A lot of scientists suspect that there must have been some interbreeding (I mean, those of you with a small percentage of Neanderthal DNA would know that you can’t inherit DNA any other way, right?).
But mitochondrial DNA from Neanderthals looks quite a bit different to that of modern humans, and some scientists were even willing to suggest that Homo sapiens and Homo neanderthalis did not interbreed…we know that isn’t true though, so let’s move on.
We now know that many of us have a small fraction of Neanderthal and Denisovan DNA, and this shared DNA probably shaped our susceptibility to certain diseases or our ability to adapt to different environments.
For example, Neanderthal genes have been linked to such ailments as type 2 diabetes, lupus, and Crohn’s disease, but on the other hand, Denisovan genes has been shown to have a high adaptability to high-altitude environments. (Wait…I’m extremely tolerant to the cold…does that mean I’m not a Neanderthal? …asking for a friend…)
While it’s understood that Homo sapiens most likely interbred with Neanderthals, the question is…HOW?!
The Missing Population
Archaeologists in Israel think they’ve discovered a previously undiscovered species from the genus Homo.
Found in what’s been referred to as the Nesher Ramla site, the fossils date back to 120,000 to 140,000 years ago.
Researchers at Tel Aviv University and the Hebrew University of Jerusalem took the fossils and identified them as a new species of early human, the morphology of these “Nesher Ramla” humans sharing a lot of features with both Neanderthals and Homo sapiens, especially in the teeth and jaw.
This new variation of human has been described as having a different skull structure than us, practically no chin at all, and very large teeth (so, the opposite of Jay Leno, right?).
Now, Nesher Ramla Homo type is being thought of as the species from which the Homo sapiens from the Middle Pleistocene developed from and that it could be the missing population that mated with Homo sapiens who left Africa and arrived in the region about 200,000 years ago.
To be clear, this means that the Nesher Ramla Homo type was an ancestor for both Homo populations in Asia as well as Neanderthals in Europe.
Professor Israel Hershkovitz says that this discovery is of great scientistic importance because it enables us to make new sense of previously found human fossils. It adds yet another piece to the puzzle of human evolution, allowing us to understand the migrations of human beings around the old world. Even though they lived so long ago, in the late middle Pleistocene (474,000-130,000 years ago), the Nesher Ramla people’s story can reveal a great deal about their descendant’s evolution and way of life.
The discovery was made by Dr. Zaider of the Hebrew University during the salvage excavations at the Nesher Ramla prehistoric site in the middle of a cement plant owned by Len Blavatnik near the city of Ramla.
The fossils were found about 8 meters underground. The excavators were able to find a large number of animal bones from horses, deer, and aurochs, as well as some stone tools and the human bones that prompted this video’s script.
This is the first new species to be identified as belonging to the genus Homo in Israel.
Dr Yossi Zaidner had this to say about the discovery, “This is an extraordinary discovery. We had never imagined that alongside Homo sapiens, archaic Homo roamed the area so late in human history. The archaeological finds associated with human fossils show that Nesher Ramla Homo possessed advanced stone-tool production technologies and most likely interacted with the local Homo sapiens.”
In fact, this discovery challenges the prevailing theory that Neanderthals originated in Europe.
A European Story No More
Before the discovery of Nesher Ramla, it was thought that Neanderthals mainly originated in Europe, but now that may no longer be the case.
Professor Hershkovitz comments on the discovery of Nesher Ramla by saying, “Before these new findings, most researchers believed the Neanderthals to be a ‘European story’, in which small groups of Neanderthals were forced to migrate southwards to escape the spreading glaciers, with some arriving in the Land of Israel about 70,000 years ago. The Nesher Ramla fossils make us question this theory, suggesting that the ancestors of European Neanderthals lived in the Levant as early as 400,000 years ago, repeatedly migrating westward to Europe and eastward to Asia. In fact, our findings imply that the famous Neanderthals of Western Europe are only the remnants of a much larger population that lived here in the Levant — and not the other way around.”
Now, there is no DNA in these fossils, but despite that fact, they still offer a solution to the mystery of how Homosapien DNA managed to penetrate the Neanderthal population before they even officially arrived.
One solution to this prior to the discovery was that a missing population of humans mated with Homo sapiens, and it was them who mated with Neanderthals before the official arrival of humans out of Africa some 200,000 years ago.
And it appears that this may be the case. Nesher Rama Homo type most likely represents that population, which has until now been missing in the fossil record.
These researchers propose that these are not the only Nesher Ramla fossils that have been discovered in the region, but rather human fossils that have perplexed scientists like those found in Tabun cave, Zuttiyeh cave, and Qesem cave (each of them over 160,000 to 400,000 years old) belong to this new species.
Dr. Rachel Sarig says, “People think in paradigms. That’s why efforts have been made to ascribe these fossils to known human groups like Homo sapiens, Homo erectus, Homo heidelbergensis, or the Neanderthals. But now we say: No. This is a group in itself, with distinct features and characteristics. At a later stage small groups of the Nesher Ramla Homo type migrated to Europe — where they evolved into the ‘classic’ Neanderthals that we are familiar with, and also to Asia, where they became archaic populations with Neanderthal-like features. As a crossroads between Africa, Europe, and Asia, the Land of Israel served as a melting pot where different human populations mixed with one another, to later spread throughout the Old World. The discovery from the Nesher Ramla site writes a new and fascinating chapter in the story of humankind.”
And Professor Gerhard Weber, an associate from Vienna University, concludes with, “Europe was not the exclusive refugium of Neanderthals from where they occasionally diffused into West Asia. We think that there was much more lateral exchange in Eurasia, and that the Levant is geographically a crucial starting point, or at least a bridgehead, for this process.”
Gerhard Weber further suggests that the story of Neanderthal evolution will be forever changed by this discovery.
Homo sapiens neanderthalensis.jpg by Luna04 – Own work, CC BY 2.5, https://creativecommons.org/licenses/by/2.5
Comparison of faces of Homo sapiens and Neanderthal.jpg by Daniela Hitzemann (left photograph), Stefan Scheer (right photograph) / unknown (reconstructions) – File:Neanderthaler,_Oase,_Rumänien_(Daniela_Hitzemann).jpg and File:Neandertaler_reconst-2.jpg, CC BY-SA 4.0, https://creativecommons.org/licenses/by-sa/4.0
Figure of Neanderthal, by Borivoje Žuža.jpg by Sadko, Wikipedia – Own work, CC BY-SA 4.0
Homo neanderthalensis.jpg by Tila Monto, CC BY-SA 3.0, https://creativecommons.org/licenses/by-sa/3.0
La Qhina 18 Rekonstruktion, Museum Neanderthal.jpg by Fährtenleser – Own work, CC BY-SA 4.0
A sediba BLACK PRINT.jpg by Cicero Moraes et alii (Luca Bezzi, Nicola Carrara, Telmo Pievani), CC BY 4.0
Homme de Tautavel 02-08.jpg by Gerbil – Own work, CC BY-SA 3.0
African Mitochondrial descent.PNG by Maulucioni – Own work, CC BY 3.0, https://creativecommons.org/licenses/by/3.0
Tobaeruption.png by Anynobody – Own work, CC BY-SA 4.0
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Calotte crânienne, type de l’espèce Homo neanderthalensis, vallée de Néander.jpg by Eunostos – Own work, CC BY-SA 4.0
Gazelle upper jaw from Misliya Cave (early Middle Paleolithic).JPG by Reuven Yeshurun, CC BY-SA 3.0