On archaic introgressions — John Hawks and the 80:20 theory

There is a gradual shift among mainstream scientists who are now accepting that modern humans are the result of different contributions from ancestral populations that took place within Africa (or possibly in the Levant), archaic people different from both Neanderthals and Denisovans.

An example of the above can be found in a recent article posted two days ago by renown anthropologist and professor at the University of Wisconsin–Madison, John Hawks, titled Modern humans evolved from an 80-20 mixture of two deep streams — Genome models are converging on a scenario in which two stem lineages separated 1.5 million years ago, and merged together 300,000 years ago.

In his post, Hawks looks into the different papers published over the past few years, that suggest ancient hominins admixed and the outcome was the human lineage. It is nicely written and mentions some of the research articles that I have mentioned in previous posts (like Padilla Iglesias, 2025, Mallick, 2016, Ragsdale, 2023, Rogers, 2026).

Hawks explores the suggestion that we evolved from the admixture of two archaic lineages, an event that took place 300,000 years ago. One of these groups provided 80% of our genes and the other one, 20%. He also suggests that the Homo naledi (Hawks played an important role in the discovery and analysis of this hominin) could be a possible ancestor of the older archaics because it split from our lineage around 1.5 million years ago (Mya). Other options are the Bodo and Kabwe hominins, but he points out that there is a gap in the fossils corresponding to the period spanning 1 to 1.5 Mya the date the two groups or "stems" split apart. Did they evolve "... from earlier, H. erectus-like ancestors"? or, as he suggests, (and this is very interesting) the basal ancestors were not living in Africa!

An Eurasian Origin

I will quote Hawks directly (highlighting is mine):

"A third scenario places the stem populations on different continents. Suppose that one of the stems, which gave rise to Neanderthals and Denisovans as well as the majority of the modern human gene pool, inhabited southwest Asia. The minority stem might then have inhabited part of East Africa or southern Africa. Putting the stem populations on different continents separated by the Sahara Desert would provide a biogeographic reason for the million-year separation of the stem populations. With low levels of gene flow like the Ragsdale model, it would be a multicontinental multiregional evolution scenario.
This scenario might fit the idea proposed by José Bermúdez de Castro and María Martinón-Torres in a 2013 paper, which proposed two “hotspots” of evolution for Pleistocene Homo, one in Southwest Asia and the other in East Africa. In their concept, the Levantine Corridor was an area with near-continuous habitation that gave rise to successive range expansions into Europe and other parts of Eurasia. Homo antecessor as represented in Spain was an early dispersal, possibly the first, and Neanderthals and Denisovans were later dispersals. The Levantine Corridor could well be the home of a Cousins-like Population A."

The suggestion of a population in the Middle East, spanning modern Israel, Lebanon, Syria, Jordania and probably Irak, and Saudi Arabia, is the origin of modern humans is very reasonable. That area was probably a vast refugium (or multiple refugia) safe from the rigors of harsh ice ages in northern Europe, and the desertification (for a recent paper on the climate in Eurasia see Zan, 2024) and arid conditions that prevailed for most of the Pleistocene. From there, pulses of hominins moved out, fanning into Eurasia (H. erectus, Dmanisi, the Flores Island hobbits, Homo antecessor, Neanderthals and Denisovans).

In the meantime, primitive archaics populated Africa south of the Sahara (H. naledi and H. rhodesiensis) which later admixed with modern humans, providing diversity to the African genome. Below is a map depicting this scenario.

The origin of humans in the Levant . A. Whittall © 20206>

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

Misterious Middle Eastern (non-African) homo, not Neanderthals or modern humans (Denisovans?)

Two 2021 papers published in Science, one by Israel Hershkovitz et al. (A Middle Pleistocene Homo from Nesher Ramla, Israel, Science 372, 1424-1428. DOI:10.1126/science.abh3169 🔒), the other by Yossi Zaidner et al. (Middle Pleistocene Homo behavior and culture at 140,000 to 120,000 years ago and interactions with Homo sapiens.Science 372, 1429-1433. DOI:10.1126/science.abh3020 🔒) describe hominins living in what is now Israel using stone tool technologies associated to both modern humans and Neanderthals yet different two both of those lineages. These fossils have been dated to around 120,000 ti 140,000 years ago (120 - 140 kya), in the Middle Pleistocene (or MP).

Not Modern Humans or Neanderthals

The second paper states that "The evidence from Nesher Ramla demonstrates that late MP Homo fully mastered advanced Levallois technology that until only recently was linked to either H. sapiens or Neanderthals." It also mentions that this stone knapping technology was due to contact between different human groups ("cultural diffusion"), and this implies that they admixed: "These results are consistent with a growing body of genetic studies suggesting that a gene flow existed between divergent archaic Homo populations and H. sapiens during the late Middle and early Late Pleistocene. Our findings provide archaeological support for close cultural interactions between different human lineages during the Middle Paleolithic period and suggest that contacts between MP Homo and H. sapiens had already occurred prior to 120 ka."

The first paper proposes that these Middle Pleistocene hominins, which they call NR, after Nesher Ramla, the site in Israe where they were found, are distinct from both modern humans and Neanderthals. They present the following unrooted phylogenetic tree (Fig 2b) which they describe as having "NR-1 close to the origin of the branch leading to African MP Homo, close to the split from the H. erectus branch and to European MP Homo and Neanderthals (including Atapuerca SH), and far from early and recent H. sapiens".

Phylogenetic tree for the Nesher Ramla homo. Fig 2b in Hershkovitz et al., 2021

Notice how it is midway between the Eurasian Homo erectus, and the African MP hominins (like the ergaster, and H. rhodesiensis).

The authors point out that their analysis of the fossils show that they are a mossaic, with "a unique combination of archaic and Neanderthal features, supporting the existence of a local, Levantine population at the final MP... showing that an affiliation of the NR fossils with early and recent H. sapiens is highly unlikely, but that it is impossible to establish whether NR fossils are more likely to be classified as MP Homo, Neanderthal, or H. erectus (the latter for the parietal only)" So, it is different from the Homo sapiens lineage yet similar to erectus, Neanderthals or MP homo. They probabilities assigned by the study are: 41% Homo erectus, 34% MP Homo, and 25% Neanderthal.

Due to their recent age of 120 to 140 ky, the researchers suggest that they are the last survivors of an ancient Southwestern Asian homo group that could include other specimens found in the Middle East, like the Quesem and Zuttiyeh Caves individuals, and also Tabun Cavre. If this is the case they lived here between 420 and 120 ky ago. They could have admixed with the Homo sapiens of Misliya Cave, and also the Neanderthals of Skhul and Qafzeh.

They propose that the Nesher Ramla Homo is the source of the populations found in Western Europe such as the Arago and Atapuerca Sima de los Huesos (SH) specimens: "... contribution of Levantine Homo groups carrying Neanderthal-like traits to European Homo lineages. The NR Homo, carrying Neanderthal-like traits, could thus represent the “source” population... according to which Western Europe was repopulated through a series of successive migrations." The paper's bibliography cites de Castro et al., 2019, who proposed an explanation for the differences between them: "...Whereas the SH teeth present an almost morphological identity with European Neanderthals, the Arago teeth exhibit a combination of plesiomorphic as well as some Neanderthal-derived features. In addition, the Arago crown dimensions are remarkably larger than those from SH, the differences being statistically significant for most variables. We hypothesize that during the Middle Pleistocene the European continent was settled at different points in time by hominin groups coming from Southwest Asia, probably from a common mother population evolving in this latter region."

What I find interesting, is that these are Eurasian hominins, all of them, none are African. It somehow hints at a Middle Eastern origin of the population that led to Neanderthals, with a link to Homo erectus, and which is also associated with Mid Pleistocene Western European hominins like the Atapuerca Homo antecessor. The MP African hominins are not even close to these Levantine people.

The paper does not state it, but it follows logically, that modern humans could have originated in this region too.

Denisovans?

A very smart suggestion posted by John Hawks is that these Nesher Ramla people were Denisovans!

Hawks wrote: "One possibility may fit well, and I've not seen anybody mention it. We already know that there was a third population out there: the Denisovans. The DNA data from central Asia show us that Neandertal and Denisovan populations were sometimes in contact with each other, across more than 100,000 years of time, and that they mixed where they met. We do not know what the geographic range of Denisovans may have been across the southern tier of Asia. Many researchers have emphasized the Denisovans as an “eastern” population, due to the high representation of Denisovan ancestry in island southeast Asia and Oceania. But we have very little fossil evidence about the ancient populations of India and Pakistan, and the known Neandertals from Teshik-Tash, Uzbekistan and Shanidar, Iraq, are more recent than 100,000 years. So why not Denisovans in the Levant before 120,000 years ago?"

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

The odd thing about Homo rhodesiensis

A research paper published in Nature in April 2020, titled Dating the skull from Broken Hill, Zambia, and its position in human evolution, that I didn't spot at that time just when the pandemic of Covid 19 locked us all up in Argentina, dated the original skull of Homo rhodesiensis, known as BH1 (Broken Hill 1) and it is much younger than expected for such a primitive hominin.

The paper by Grün, R., Pike, A., McDermott, F. et al. (Nature 580, 372–375 (2020). https://doi.org/10.1038/s41586-020-2165-4) reports how they studied the Pleistocene skull discovered in 1921 in a mine at Broken Hill (now Kabwe), in what then was known as Rhodesia (now Zambia), from a site known as Broken Hill. The specimen had been described by Woodward that same year and named the Rhodesian man (Homo rhodesiensis), a new species. Currently it has been included into the same line as the European Homo heidelbergensis and therefore, the ancestor of Neanderthals and maybe, also modern humans.

Those who studied it, dated it to around 500,000 years ago but did so assuming it was similar to the European Homo heidelbergensis which is that age, and also using estimations based on correlations with other sites in Africa and fauna found at the site.

That age makes it old enough to be an ancestor of both Neanderhtals and Homo sapiens, and inside Africa it provides support to the African origin of both species. However, and this is a crucial point, the original site at Broken Hill was razed as it was mined away, and in the 1920s, dating of ancient specimens was more guess work and good will than science. So, Grün et al., decided to date it with modern technology, analyzing the skull itself.

A very recent primitive hominin

They found that its "best age estimate of 299 ± 25 thousand years" which is coincidental with the date given for the first modern humans, in North Africa, and the very primitive Homo naledi in South Africa! The authors write: "The result suggests that later Middle Pleistocene Africa contained multiple contemporaneous hominin lineages (that is, Homo sapiens, H. heidelbergensis/H. rhodesiensis and Homo naledi)" which is quite surprising. They try to play down this odd situation by saying that in Asia the situation was similar: "where Homo neanderthalensis, the Denisovans, Homo floresiensis, Homo luzonensis and perhaps also Homo heidelbergensis and Homo erectus were found contemporaneously". Indeed, but it should be noted that the minute Flores and Luzon people were isolated on insular habitats. Erectus was on the brink of extinction, and regarding Denisovans and Neanderthals it is widely accepted that they admixed and trysted with modern humans, and with each other (and, regarding Denisovans, very likely with erectus). But when it comes to Africa we are asked to believe that modern humans appeared and never mixed with any of these archaics that populated the continents.

But the researchers can't escape the fact that a very recent yet primitive hominin co-existed inside of Africa with modern humans, the write: "The age estimate also raises further questions about the mode of evolution of H. sapiens in Africa and whether H. heidelbergensi/H. rhodesiensis was a direct ancestor of our species."

Correct! If modern humans had already evolved 300 ky ago, then, how could the Homo rhodesiensis with that same age, be our ancestor? Furthermore, it has prmitivie traits: solid skull (relatively large at 1280 cm³, low forehead, prominent brow ridges.

A paper by Balzeau et al., 2017 studied the shape of the BH1 skull, and its dimensions and thickness, comparing it to other archaic hominins. It reported that its thick parietal bones resemble the Homo erectus and is unlike the "morphology observed in Neandertals and H. sapiens." Together with the Petralona skull (equally primitive, but found in Greece and also recent —286 ky) the Rhodesian man shares "a thick frontal torus or a thickened postero-lateral parietal bone... The main peculiarity of BH1 is related to its large, thick frontal torus and to high thickness values for the vault." The paper concludes that it is distinct from Neanderthals and modern humans and similar to the Homo erectus sensu lato (in a broad manner): ".. this fossil does not exhibit the apomorphic conditions observed in either Neandertals or among H. sapiens."

See the skull below, and judge for yourself:

Side and front views of the Kabwe skull, Broken Hill, Rhodesian man. Source

I have posted often, that Africa was a melting pot of primitive hominins, blending into the stock of African Homo sapiens, and adding diversity to its genetic pool.

H. Rhodesiensis

Some scholars have proposed a new name for the specimen, dropping "Rhodesian man" and renaming it Bodo man, or Homo bodoensis (yes, wokeness seeks to decolonize anthropology and remove the tainted, imperialist reference to Cecil Rhodes who gave his name to Rhodesia). However, this will not solve the issue of its recent age and perhaps, its location on a dead end branch of hominins. In a recent post we mentioned a paper that analyzed the shape of the faces of humans and ancestral hominins. It reported that "The evidence instead suggests that the large and non-H. sapiens-like faces of Bodo and Broken Hill 1 ... represent taxonomic diversity in the African MP record, which could exclude the large fossils assigned to H. heidelbergensis and H. rhodesiensis as representative of an ancestral morph for H. sapiens." Meaning that they are not our ancestors.

Finally, the similarity of the Rhodesian man and Petralona was noted by Falgueres et al., 2025 and they place them together, it in a parallel and independent lineage to that of Neanderthals: " our view, the similarities in midfacial and cranial contours between Kabwe and Petralona and the absence of true Neanderthal apomorphies in their midfaces suggest that European and African samples often assigned to H. heidelbergensis (Stringer, 2012; Rightmire, 2017) remained closely related during most of the Middle Pleistocene, alongside and independent of the Neanderthal lineage. Our results from dating the matrix attached to the Petralona cranium suggest that like the Kabwe cranium, the Petralona cranium may date to about 300 ka, consistent with their persistence into the later Middle Pleistocene" They also note that their work supports the notion put forward by Quam et al., 2023 and Ashton et al., 2016, that Middle Pleistocene hominins can be grouped into two separate lineages:

One lacking Neanderthal-like features, that includes the following speciments: "Mauer, Mala Balanica, Montmaurin, Visogliano, and one of the Arago mandibles" as well as the more recent Petralona skull. The second group has Neanderthal-like features, and comprises "the Atapuerca, SH fossils, Arago 2, and specimens from Payre, Ehringsdorf, and Bau de l'Aubesier."

Taken together the data seems to suggest that Homo heidelbergensis and the Rhodesian homo from Africa may not be linked to Neanderthals or modern humans.

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