Neanderthals actually came from Human Beings! (March 2026 paper says)

A very interesting suggestion was prepublished on March 13 in Biorxiv by David Reich, 2026, it is work in progress, and a model, but its title tells it all: Hypothesis: A modern human range expansion ~300,000 years ago explains Neandertal origins.

Trying to explain why the split date between the human lineage and Neanderthals differs when you consider nuclear DNA (765-550 kya) or mtDNA (365-400 kya), or why the original Y chromosome of Neanderthals appears to have vanished, and what we have found is so similar to ours, and that their mtDNA is remarkably similar to ours, Reich suggests that they are a population that arose from modern humans introgression with archaics in Europe. This also explains some incongruent dates and other oddities found in the Atapuerca Sima de los Huesos remains. Simple hypothesis that is very similar to the proposal maed by Cosimo Posth published in Nature, which I commented in a post back in 2017 (An even older Out of Africa event (270kya)!!). Posth suggested that African inflow was "responsible for providing the mtDNA to the Late Pleistocene Neanderthals might have been an even earlier Middle Pleistocene gene flow from Africa, occurring in a time interval that we date between 413 and 268 ka... The temporal corridor for this introgression event between 460 ka and 219 ka is compatible with the evidence of archaeological similarities between Africa and western Eurasia during the Lower to Middle Paleolithic transition39 and potentially may explain the dissimilarities in Middle Paleolithic industries between eastern and western Eurasia. Environmental changes across this time span might have facilitated a hominin expansion out of Africa and potentially spread cultural innovations such as the Levallois technology into Eurasia." Reich developed the concept. Below is the Abstract of Reich's paper

"Abstract.
This paper demonstrates the feasibility of the hypothesis that Neandertals formed when a population using recently developed Levallois stone tool technology expanded between 400-250 thousand years ago (ka). In Europe, their range expansion into an area with Sima de los Huesos-like people led to massive introgression of local archaic genes producing a population with around 95% archaic ancestry (Neandertals); if this range expansion was sex-biased it would provide a simple explanation for why Neandertals retain modern human lineage Y chromosomes or mitochondrial DNA. In Africa, interbreeding with local archaic humans led to more modest archaic admixture and the deep substructure detected in all modern humans today. This proposal explains four previously perplexing similarities of modern humans and Neandertals—sharing of mitochondrial DNA, Y chromosomes, Levallois tools, and 300-200 ka date of formation by mixture—even while Neandertals and Denisovans cluster genome-wide."

This is the paper: Hypothesis: A modern human range expansion ~300,000 years ago explains Neandertal origins David Reich. bioRxiv 2026.03.11.711219; doi: https://doi.org/10.64898/2026.03.11.711219.

This paper is interesting because it also mentions humans mixing with archaics inside of Africa, a source of diversity:

"... ancestors of all modern humans including sub-Saharan Africans were deeply substructured, due to the coming together a few hundred thousand years ago of lineages that began diverging a million or more years ago. For example, ref. 16 models modern human ancestry as largely derived from a mixture of about 80% from a lineage that was most closely related to Neandertals and Denisovans, and 20% from a lineage that diverged from it around 1.5 million years ago, with the two coming together around 300 ka. The remixture is estimated to date to around the same time as the genetically inferred interbreeding of modern humans and archaic humans in the ancestors of Neandertals 300-200 ka. This raises the possibility that these mixtures in Europe and Africa had related causes: a range expansion of a successful population interbreeding with local archaic groups. In Europe, there was massive introgression of local genes because barriers to producing viable offspring were few. In Africa, the mixture was with a more divergent archaic lineage, result in a lower γ (cross-group interbreeding rate), and less introgression..."

This is the reference "ref. 16" cited above: Cousins T, Scally A, Durbin R, (2025) A structured coalescent model reveals deep ancestral structure shared by all modern humans. Nat Genet 57, 856–864.

Comments

I am surprised at the different conclusions that the same datasets of human genes and fossils produce (some are mutually exclusive): humans and Neanderthals are the same, humans and Neanderths split after the Denisovans split, Denisovans and humans split after the Neanderthal split, dates that range from 500 to over 1 million years, introgressions all over (Denisovan to Neanderthal to Human, Human to Neanderthal, Denisovan to Human, one or more lineages of superarchaics introgressing into different hominins). Surely they can't all be right.

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Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia Copyright 2009-2026 by Austin Whittall © 

An earlier Human - Neanderthal split? (400,000 years earlier!)

Aida Gómez-Robles published a paper in Science Advances three days ago (May 15, 2019 - Dental evolutionary rates and its implications for the Neanderthal–modern human divergence, Vol. 5, no. 5, eaaw1268 DOI: 10.1126/sciadv.aaw1268) in which she finds evidence that "support[s] a pre–800 ka last common ancestor for Neanderthals and modern humans unless hitherto unexplained mechanisms sped up dental evolution in early Neanderthals".

This is really remarkable, as it pushes the conventionally accepted date of divergence back in time from 400 to 800 thousand years ago.

This far older age was worked out by studying ancient Neanderthal teeth from the Sima de los Huesos site in Spain.

Gomez-Robles compared fossilised teeth from archaic hominins such as Australopithecus afarensis, Australopithecus africanus, Paranthropus robustus, Paranthropus boisei, and ancient ones such as Homo habilis, Asian specimens of H. erectus, a Sima de los Huesos H. neanderthalensis and of course, us: Homo sapiens, Other Neanderthal teeth from different sites in Europe were deliberatel left out of the comparative study.

The idea behind the comparison was to see how the shape of teeth in hominins changed over time. Gomez-Robles found that they evolve, and do so at a steady pace. This let estimate when each of these species split from each other.

The conclusion: "The simplest explanation of the results presented in this study is that Neanderthals and modern humans diverged before 0.8 Ma ago", our Last Common Ancestor (LCA) with Neanderthals dates back to 800,000 years ago.

Gomez-Robles goes on to spell out the implications of this more ancient split:

" If the phenotypic LCA of Neanderthals and modern humans was older than 800 ka, this would imply that all fossil hominins younger than this age are no longer valid candidates to occupy this ancestral position. Some fossils younger than this age, however, are frequently considered to be part of the last common ancestral species to Neanderthals and modern humans. These fossils, usually ascribed to Homo heidelbergensis, include European and African specimens, such as Mauer, Arago, Petralona, Bodo, Kabwe, etc., and maybe even some Asian specimens. If Neanderthals and modern humans diverged earlier than 800 ka ago, then all these fossils have to be related either to Neanderthals or to modern humans, or they can be part of a sister lineage to both of them. These fossils, however, cannot be ancestral to Neanderthals and modern humans because they would postdate their evolutionary divergence. An evolutionary relationship between these fossils and both Neanderthals and modern humans would be possible only if they were part of an older ancestral species that persisted in time as a relic species after the actual split of both lineages. Effectively, this scenario would mean that the H. heidelbergensis fossils are part of a sister group to Neanderthals and modern humans but that the evolutionary change from their putative ancestral populations did not involve speciation."

Of course, there are confounding factors that can explain the structural differences in teeth without requiring such an older age, for instance: the teeth evolved quicker in a small population of Neanderthals, isolated from other human groups, making them seem older while they are actually only 400 Ky old.

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Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia Copyright 2009-2019 by Austin Whittall © 

Atapuerca Sima de los Huesos remains were closer to the Neanderthals

Four and a half years ago I posted about a site in Spain, known as Atapuerca (What Science is all about), in it, I mentioned two studies that came to different conclusions: one stated that the human remains there resembled Neanderthals, the other that they were closer to the Denisovans than to the Neanderthals.

Today I read a paper that was published on Nov. 30, 2018 and which states that the teeth of remains from Atapuerca's Sima de los Huesos site shows that they had a close relationship to the later Neanderthal groups found in Europe.

The paywall protected abstract says:

"Enamel and dentin patterns have awakened a considerable interest in phylogenetic studies. However, almost nothing is known about the dental tissue proportions of European Pleistocene hominins, apart from Neanderthal populations. This study aims to assess the three-dimensional dental tissue proportions of permanent canines belonging to the extensive sample of hominin teeth at Sierra de Atapuerca (Spain) through the use of microtomographic techniques. Our results show that early and middle Pleistocene populations from Atapuerca exhibit large coronal and root dentine dimensions, as well as a thinly enamelled pattern, which has been traditionally considered an autapomorphic Neanderthal trait. Therefore, these results might support an early enamel thickness decrease which is already observed 800 kyr ago in Homo antecessor and maintained in later groups such as Sima de los Huesos and Neanderthal populations during the middle Pleistocene."

This is important because it shows that the Sima de los Huesos remains had a close relationship with the Homo neanderthalensis.

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Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia Copyright 2009-2018 by Austin Whittall © 

An even older Out of Africa event (270kya)!!

A paper published in Nature, by Cosimo Posth et al, published in Nature looks into the odd discrepancy in the age of the split between Modern Human and Neanderthal genomes

The date of the split between humans and Neanderthals differs when you consider their nuclear or their mtDNA:

• Nuclear DNA says that humans and Nearnderthals split some 765,000 to 550,000 years ago
• Mitochondrial DNA or mtDNA says we split 365,000 to 400,000 years ago

I believe that discrepancies are what makes science leap forward (like the problems caused by the "ether" theory that led to relativity and quantum physics). And a gap like this of several hundreds of thousands of years is a big discrepancy. Either the dating is all wrong and has to be reviewed (ie. mutation rates and so forth), or the current ideas on the migration and origin of Homo sapiens are incorrect.

The paper looks into the mtDNA extracted a "complete mtDNA of an archaic femur from the Hohlenstein–Stadel (HST) cave in southwestern Germany. HST carries the deepest divergent mtDNA lineage that splits from other Neanderthals ∼270,000 years ago..."

This date of 270 kya is actualy the average, the real divergence date between HST and all other Neanderthals (95% HPD) is between 316 and 219 kya. The Altai Neanderthals split from the other Neanderthals some ∼160,000 years ago (95% HPD of 199 - 125 kya).


This paper tries to explain the genetic incongruence of Sima de los Huesos (see my post Sima de los Huesos remains, Neanderthals, Denisovans and their nuclear and mtDNA), the remains from Sima de los Huesos in Spain which are 430 ky old, have mtDNA that resembles that of Denisovans more closely than that of the Neanderthals. But, their nuclear DNA is more similar to that of Neanderthals than to Denisovan nuclear DNA.

The authors write (Bold is mine) that the nuclear DNA (nDNA) "... from the Sima de los Huesos site... confirmed their closer affinity to the Neanderthal lineage, suggesting that at least by ∼430 ka, Neanderthals and Denisovans had already diverged. However, in contrast to genome-wide data, the Sima de los Huesos mtDNA was found to branch off with the deeply divergent Denisovan mtDNA lineage. The phylogenetic discrepancies could be reconciled if the mtDNA of early Neanderthals was indeed Denisovan-like and was subsequently replaced by a more derived mtDNA lineage.".

This "derived mtDNA" got into the Neanderthals through " a genetic introgression event from African hominins into the early Neanderthal population that gave rise to the ‘Late Pleistocene’ Neanderthal mtDNA lineage".

This introgression took place long ago, and came from " an African source, which we constrain taking place more than ∼270 ka". In other words the paper suggests an Out of Africa event over 270,000 years ago which admixed human mtDNA into Neanderthals, mtDNA which replaced the older mtDNA -i.e. Denisovan and Sima de los Huesos hominin, with a new lineage, the "African mtDNA that evolved into the Late Pleistocene Neanderthal mtDNA type". And this "new" mtDNA spread from the HST Neanderthal in Germany to all others, including Sidron in Spain and eastwards all the way to Altai. Thousands of kilometers from the Atlantic to Siberia.

Furthermore, they estimate that "if Ne (effective population) was <5,000 units, a mean temporal interval of 300 ka is sufficient for an incoming mtDNA lineage below 0.1% in frequency to drift up to fixation." in other words, a very small initial input of "African genes".
But looking at this theory with a critical eye, we must point out that Neanderthals were spread out over a very wide area, which makes it very difficult for this replacement to take place in the whole population.

Furthermore a different explanation can be found: if modern humans were already outside of Africa i.e. in Asia, and they mixed with the Neanderthals outside of Africa -no Africans involved in the introgression. They would have had plenty of time to admix over a wide area, and this would also explain why there was an Ancient gene flow from early modern humans into Eastern Neanderthals 100,000 years ago as suggested by Martin Kuhlwilm et al, in Nature, Feb. 2016. DOI:10.1038/nature16544.

So instead of suggesting an earlier migration (it actually took place 1.8 Mya when Homo erectus left Africa for Asia) why not think about H. sapiens living in Eurasia and mixing with Neanderthals?

I wonder how this ties in with the Oldest Homo sapiens remains dating back to 315,000 years ago, found in Morocco?
 
Sources

(1) Deeply divergent archaic mitochondrial genome provides lower time boundary for African gene flow into Neanderthals, Cosimo Posth, Christoph Wißing, Keiko Kitagawa, Luca Pagani, Laura van Holstein, Fernando Racimo, Kurt Wehrberger, Nicholas J. Conard, Claus Joachim Kind, Hervé Bocherens & Johannes Krause. Nature Communications 8, Article number: 16046 (2017). doi:10.1038/ncomms16046.

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Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia Copyright 2009-2017 by Austin Whittall ©

Sima de los Huesos remains, Neanderthals, Denisovans and their nuclear and mtDNA

A very interesting paper published in Nature (Matthias Meyer et al.) has confirmed that the Sima de los Huesos remains, that are 430 ky old, have mtDNA that resembles that of Denisovans more closely than that of the Neanderthals. But, their nuclear DNA is more similar to that of Neanderthals than to Denisovan nuclear DNA.

Since the Sima de los Huesos hominins are supposed to be the ancestors of Neanderthals it is reasonable that their nuclear DNA is similar to that of Neanderthals and different from Denisovans. But why is the relationship regarding mtDNA exactly the opposite?

The paper offers three explanations:

1. The Sima de los Huesos people had two very diverging mtDNA types, one leading to Neanderthals the other to Denisovans, and these samples are of the first kind.
2. Some "other" hominin contributed its mtDNA to both Denisovans and Sima de los Huesos people
3. The original proto Neanderthal mtDNA was inherited by their Neanderthal descent but was completely diluted by later inflow of Neanderthal mtDNA from Africa, which we find in more recent Neanderthals.

In science, the breakthroughs come from finding the correct answer to discrepancies like these. So it is very exciting and who knows what will eventually be learned from this!.

Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia Copyright 2009-2014 by Austin Whittall © 

Sima de los huesos is now.... closer to Neanderthals than Denisovans!

Earlier this year I wrote a post about the Sima de los Huesos remains and its possible linkeage to Homo erectus. I was commenting on a paper that had sequenced the mtDNA of the remains from this Spanish site and found it "to be closer to Denisovan mtDNA than to Neanderthal ⁄ Human mtDNA. This is quite hard to explain: how did Denisovans get more of this mtDNA than the Neanderthals did considering that Denisovans are located in Altai while Neandertals are located in between Spain and Altai?".

Well it appears that the mtDNA was closer to Denisovans, but today I read another article (DNA from Neandertal relative may shake up human family tree, by Ann Gibbons, Science 11.Sep. 2015) which says that:

After 2 years of intense effort, paleogeneticist Matthias Meyer of the Max Planck Institute for Evolutionary Anthropology has finally sequenced enough nuclear DNA from fossils of a tooth and a leg bone from the pit to solve the mystery. The task was especially challenging because the ancient DNA was degraded to short fragments, made up of as few as 25 to 40 single nucleotides. (Nucleotides—also known as base pairs—are the building blocks of DNA.) Although he and his colleagues did not sequence the entire genomes of the fossils, Meyer reported at the meeting that they did get 1 million to 2 million base pairs of ancient nuclear DNA.
 
They scanned this DNA for unique markers found only in Neandertals or Denisovans or modern humans, and found that the two Sima fossils shared far more alleles—different nucleotides at the same address in the genome—with Neandertals than Denisovans or modern humans. “Indeed, the Sima de los Huesos specimens are early Neandertals or related to early Neandertals,” suggesting that the split of Denisovans and Neandertals should be moved back in time, Meyer reported at the meeting...

This is very interesting since it pushes the ancestors of Denisovans and Humans split from the linage leading to Sima de los Huesos earlier than expected. But also, (because that explains how the mtDNA that is closer to Denisovans was found in Sima de los Huesos remains) they did interbreed after they split apart.

The allegory of an evolutionary tree is not the best way to describe our origins. It is more like a tree with criss-crossing branches that split from a common trunk much earlier than expected.

The early splitting is no problem from my point of view, in fact I have written some posts about an earlier origin of humans, but it is a problem for those who base their "molecular clocks" and adjust them based on dates which, are in fact quite wrong. The process can be summarized as follows:

We look at populations (say Amerindians) and jot down their haplogroup markers, and we assume that they mutated when they reached America and then, we guess the date they entered America (say 15 kya). With this we calibrate our clock. We again look at the humans closest to Africa and jot down their haplogroups markers, and once again guess the date these people's ancestors left Africa (say 70 kya), and again calibrate our clock. We take another look at the oldest fossils of AMH in Africa (195 kya) and jot down the most divergent African haplogroups' markers, we recalibrate our clock again. But, as you can see, there are many assumptions in all of this (the dates and, above all, the assumption that these haplogroups are specifically human and mutated recently < 200 ky!).

But what if the origin of H. sapiens was not 200 kya but 300 or 350 kya? this alters the mutation rates, so America could have been peopled much earlier...

More findings will help us understand this better.

A closing thought

The common mtDNA shared by Denisovans and Sima de los Huesos but not the nuclear DNA could be explained as follows:

• Archaic population lives in Eurasia (H. erectus?) with its specific DNA and mtDNA they are the ancestors of Denisovans and a pre-Sima de los Huesos people.
• A later wave of proto-Neandertal reach Europe, they are more successful and breed with the native women of pre-Sima de los Huesos stock. The original mtDNA is preserved in their offspring, but the nuclear DNA is now admixed with proto-Neandertal. After many generations we have a European lineage with mtDNA similar to the original stock and therefore shared with Denisovans, but a DNA which will be more like that of Neanderthals.

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Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia Copyright 2009-2015 by Austin Whittall © 

Were Denisovans the last Homo erectus?

My previous post mentioned the new findings regarding Denisova admixture in Homo sapiens, and the two theories proposed to explain how Denisovan DNA spread between Austronesians and East Asians - Native Americans.

I believe that sooner or later we will find out that the elusive Denisovans are no others than Homo erectus. And I base my suspicions on two facts:

Erectus were alive in South East Asia about 40 kya. This was proved by Yokoyama Y, Falguères C, Sémah F, Jacob T and Grün R, in their paper (2008) Gamma-ray spectrometric dating of late Homo erectus skulls from Ngandong and Sambungmacan, Central Java, Indonesia. J Hum Evol. 2008 Aug;55(2):274-7. doi: 10.1016/j.jhevol.2008.01.006. Epub 2008 May 14., the team concluded that: "we establish[ed] minimum age estimates of around 40ka, with an upper age limit of around 60 to 70ka. This means that the Homo erectus of Java very likely survived the Toba eruption and may have been contemporaneous with the earliest Homo sapiens in Southeast Asia and Australasia..

The 400 ky Sima de los Huesos remains from Spain also hint at this. The mtDNA of the remains from this Spanish site was sequenced and found to be closer to Denisovan mtDNA than to Neanderthal ⁄ Human mtDNA. This is quite hard to explain: how did Denisovans get more of this mtDNA than the Neanderthals did considering that Denisovans are located in Altai while Neandertals are located in between Spain and Altai? The authors offer 4 explanations, and I believe that their fourth is correct: bold font is mine [1]

A fourth possible scenario is that gene flow from another hominin population brought the Denisova-like mtDNA into the Sima de los Huesos population or its ancestors. Such a hominin group might have also contributed mtDNA to the Densiovans in Asia. Based on the fossil record, more than one evolutionary lineage may have existed in Europe during the Middle Pleistocene. Several fossils have been found in Europe as well as in Africa and Asia that are close in time to Sima de los Huesos but do not exhibit clear Neanderthal traits. These fossils are often grouped into H. heidelbergensis, a taxon that is difficult to define, particularly with regard to whether the Sima de los Huesos hominins should be included. Furthermore, there may have been relict populations of still earlier hominins, notably those classified as Homo antecessor, which share some morphological traits with Asian Homo erectus and have been found just a few hundred metres away from Sima de los Huesos in Gran Dolina.

[1]

Home erectus left Africa (or maybe even originated out of Africa, in Asia from H. Habilis who had migrated earlier, and some of them returned to Africa later, generating the African erectus.) 1.8 Mya. They had plenty of time to move across Eurasia, fromm Indonesia to China to, why not?, Spain. Surely they originated more "modern" versions as time passed, the Homo antecessor and later H. heidelbergensis could be some of them. As well as Denisovans.

Maybe they even marched all the way to the New World.

Later, when modern H. sapiens moved into their territories they admixed, in varying degrees. This admixture must depend on the population ratios of migrants and residents. We have therefore a high content of Denisovan gene flow in Austronesia, and also in East Asia and the New World. But they may have been the result of separate admixture events.

Orthodoxy requires that the Humans marching into America be the result of a split that took place in Asia. And if these future Amerindians were the only ones to enter America, then they had to admix with Denisovans in Asia. But neat theories are not the way Nature works. The history of our genetic makeup is much more complex. And it may involve admixture in the New World, both with Neandertals and Denisovans

Sources

[1] Matthias Meyer, Qiaomei Fu, ,et al., A mitochondrial genome sequence of a hominin from Sima de los Huesos, Nature 505, 403–406 (16 January 2014) doi:10.1038/nature12788

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Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia Copyright 2009-2015 by Austin Whittall © 

What Science is all about

A micro mini post

The latest paper on Neanderthals is one dealing with crania found at the Sima de los Huesos site in Atapuerca, Spain: Seventeen skulls were pieced together and showed a mixture of archaic and Neanderthal features. These people, were the ancestors of Neanderthals (maybe not their direct ancestors, but somewhere in their past!). They were dated to 430 kya.

But this brought to my mind another paper on Sima de los Huesos, which sequenced DNA from a 400 kya specimen (maybe one of those mentioned above), and found that they were closer to the Denisovans than to the Neanderthals!.

So one paper says the Atapuercan remains are ancestral to Neanderthal, and another says they are closer to Denisovans than to Neanderthals...

This brings me to the title of this post: science is built on discrepancies, on conflicting data. They have to be explained in a clear and rational manner that satisfies all the evidence. I expect more will come from Atapuerca and it will help us understand our human past better.

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Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia Copyright 2009-2014 by Austin Whittall ©