OOA Routes: Sinai (Post 4)

This is the third post in my series on the possible routes taken by hominins in their Out Of Africa (OOA), or into Africa in back migrations over the course of the past 2 million years.

Post 1: Where was the Out of Africa Corridor?
Post 2: OOA Routes: Gibraltar
Post 3: OOA Routes: Strait of Sicily
Post 4: OOA Routes: Sinai
Post 5: OOA Routes: Bab-el-Mandeb

Sinai, the northern route across the Red Sea

Africa is really a vast peninsula of Eurasia, linked by a narrow strip of land that runs between the northern tip of the Gulf of Suez and the Mediterranean Sea. This stretch of desert is roughly 120 km long (76 miles). Since 1869, the Suez Canal runs across this isthmus.

On the eastern side of the isthmus lies in Asia, and is known as Sinai Peninsula, with an area of 62,000 km² (24,000 sq.mi.), jutting into the Red Sea, which surrounds it with two narrow and long gulfs, the Gulf of Suez to the west, and the Gulf of Aqaba to the east. The land connection with the rest of Asia runs along the Egyptian border with Israel.

This area marked by the confluence of different tectonic plates that are splitting the crust of the earth. The rift started to form around 28 million years ago and is still widening by 0.25 to 0.5 mm (1/100 to 1/50 inch) per year. The eastern side is also being uplifted. (Fernández-Blanco, 2025).

Africa lies to the west of the isthums. This region is part of Egypt, and the fan shaped Nile Delta (named for the Greek letter "d" = δ) is adjacent to the Asian-African border.

The delta is a fertile, humid haven in the middle of a vast arid region. The River Nile, flows into the Mediterranean here along two main branches (Rosetta and Damietta), at one time the delta had several addutuibak brabcges and they fanned out further west and east than the present delta. However, the tectonic movement of the Sinai Plate uplifted the eastern edge, causing the easternmost river channel, the Pelusiac River, to silt up, and dry out around 2800 years ago (Stanley, 2008). You can see the site of the former city of Pelusium in Google maps located 21 km, 13 mi. east of the Suez Canal (See Sneh, 1973).

This corridor is the only dry, solid ground, route out of Africa. It did not require crossing any seas, navigating or island-hopping. It was used by animals moving to and fro the Levant. The only complication is that the Sinai is an arid, rugged territory with no permanent rivers or lakes. Rainfall is scarce (120 to 200 mm - 5 to 8 inches per year). This lack of water and desertic conditions are an obstacle. But, it wasn't always like it is now.

The Green & Wet periods

I will follow Breeze, 2016 who has identified several humid periods over the past 250 thousand years that could have favored the migration of human beings across this parched territory and allowed them to cross from the Nile delta to the valley of the Jordan River, and from there, into Western Eurasia. These periods are the following:

• MIS 7. 243 to 191 ka (thousand years) ago. A humid period in NE Africa, Arabia, and the Middle East. The Nile carried plenty of water. Which "raises the possibility of dispersals out of Africa."
• MIS 6. 191 to 130 ka. Continued humidity and from 180 to 170 ka, wet climate in NE Africa and the Levant. Sea levels were lower, allowing for alternate, shorter routes that are now submerged. From 178 to 152 ka, the areas of Jerusalem Dead Sea, all the way to the north of Levant were humid and much wetter, and cooler than nowadays.
• MIS 5e and transition from MIS 6 to 5e (137 to 114 ka). There was a well watered route along the current Nefud desert along the Tabuk Corridor (from Levant, across Arabia towards the Persian Gulf).
• MIS 5a (85-71 ka). A revived damp Tabuk-Nafhyd corridor, a greater flow on the Nile and a slightly humid Sahara.

This brief summary shows that there were plenty of windows between 243 to 71 ka for humans to cross the Sinai and surrounding deserts. This also ocurred many times since our homo ancestors appeared.

The different geography of those days also involved exposed continental shelves along the Mediterranean, a Nile River that flowed further east (Pelusic Branch or similar paleo-branches). Higher rainfall would have formed, along the coastal areas, rivers and streams running into the sea. Breeze notes that this route was used by the hippopotamus "to disperse from Africa to the Levant at the end of the last glacial."

Over the past ten thousand years, as the Egyptian and other cultures appeared in the region, the Sinai ecosystem was altered by human activity. Trees were felled, plant coverage was lost, the topsoil washed away, this led to fewer plants, less rain, and a vicious circle of desertification.

Neanderthals and Erectus in the Levant

Before modern humans, what is now Israel was the home of Homo erectus, and Neanderthals. Goren-Inbar, 2000 summarizes this as follows: There is evidence of Early Pleistocene populations 1.4 million years ago at ‘Ubeidiya with typical Acheulean erectus tools. A more recent site is Evron Quarry (1 million years).

More recently, and with another cultural setting is the Gesher Benot Ya’aqov (or GBY) site (780 ka) which the authors link to "yet another human movement out of Africa." Interestingly the stone tools from this site are not found in similar aged sites across Eurasia, only later did they appear across the continent.

Fire has been recorded at this site too 790 kya (Goren-Inbar, 2004). But who lit them is not known "The producers of the Acheulian material culture have frequently been assumed to be Homo erectus or Homo ergaster; at GBY they may just as well have been archaic Homo sapiens." This closing comment is relevant, because our species, H. sapiens is said to have appared 300 kya. If they are humans, this date is further back than accepted, even older than the split of Neanderthals and Denisovans, and that of humans and the ancestors of Neanderthals and Denisovans.

Homo ergaster is a "sister" species, a variety of African erectus.

The facts are that there are 1.8 million-year-old tools and fossils in Asia of erectus origin (see Yunxian, China), very ancient fossils at Dmanisi, Georgia and even older tools, at Zarqa in Jordania (2.4 My), and Masol, India (2.6 My) probably made by an earlier homo species. This suggests that the movement of hominins out of, and into Africa is ancient, and also, that the obvious route from Africa to Jordania and the Caucasus is through Sinai.

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

Archaic Admixture in Africans (23%)

A research paper published by Fan et al., in Cell, in 2023 reported their findings regarding genetic diversity in Africa, as well as suggesting archaic introgression of very divergent ancestors into all humans, in Africa, and also a recent introgression into some specific populations.

This is the paper: Fan S,. Whole-genome sequencing reveals a complex African population demographic history and signatures of local adaptation. Cell. 2023 Mar 2;186(5):923-939.e14. doi: 10.1016/j.cell.2023.01.042. PMID: 36868214; PMCID: PMC10568978.

Introgression

There are two populations that stand out in their analysis. One is the Tikari, from the Tropical jungles of Cameroon in Western Africa, the other are the Herero, from Botswana, the same region where the Ju|’hoansi and !Xoo, San or Khoisan people, come from. The authors note that they have up to 23% of a divergent archaic genetic content, that is olver than the split of all modern humans (highlight is mine):

"The relationship of the Tikari and Herero with other populations is complex. They could be modeled as having 23% ancestry related to an archaic population that diverged prior to the divergence of all modern human populations (possibly reflecting introgression from an archaic population into modern populations) and 77% ancestry from a population related to the Nilo-Saharan-speaking Mursi. A similar pattern was observed in the ADMIXTURE analyses at K = 7 to 11 but with much lower inferred Nilo-Saharan-related ancestries in the Tikari and Herero (Figure S2). The TreeMix analyses showed evidence of gene flow between the Mursi and the ancestors of the Tikari and Herero starting at 5 migration events (Figure S3F). The results indicating archaic introgression in a population ancestral to the Bantu-speaking lineage are consistent with previous studies based on ancient African samples which suggested that the West African Niger-Congo-speaking populations carry lineages ancestral to all modern human lineages. However, time-resolved demographic history models inferred using alternate methods (described below) suggest that the ancestors of San and RHG may have been the first to split from other modern human lineages."

The gene flow from Mursi, an East African group from Ethiopia into West Africa is remarkable. Notice how the quote ends with a comment stating "yes, they may have archaic introgression, but, other methods show that the San are part of the oldest human lineage.

This ancient group, the archaics, split from us 1 to 3 million years ago. But, the authors also suggest an alternate explanation: structured populations. Isolated groups of humans exchanging alleles every now and then would produce the same effect as a ghost introgression:

"Across all pairs of populations, we inferred that all modern humans descend from deeply structured populations and that they derive approximately 5–15% of their ancestry from a lineage that may have diverged as long ago as 1–3 Mya (Figure 4C), consistent with previous findings suggesting archaic introgression in some African populations.However, such a model is also consistent with the population ancestral to modern humans being deeply structured."

They paint a complex scenario with "multiple episodes of gene flow between modern human lineages and possibly with other hominid lineages"

Below is a tree showing the splits and archaic introgressions (San on the right, non-Africans, left. Africans in between).

D: Summarization of the results of demographic analyses. Blue bars show inferred gene flow among modern human populations. OOA: out of Africa populations. Ghost: inferred introgression from a ghost population. We observe evidence of introgression from a deeply diverged population into the ancestor of all modern human populations. In addition, the Bantu-speaking and RHG populations show some ancestry that is very old, possibly reflecting subsequent introgression with a deeply diverged population.. Fan et al., 2023

Pale Skin, shared by San and Europeans

As discussed in a previous post, San and non-Africans share a variant linked to pale skin pigmentation. This paper reports that "rs1800404, a synonymous variant in exon 10, associates with skin pigmentation and eye color variation across multiple ethnicities. The light-pigmentation associated allele rs1800404-T, which is a splicing QTL of OCA252,58, is most frequent in the San (83%) compared to all other populations in the present study and gnomAD except for the Finnish population (frequency of 84%)." The supplementary material table S4 shows the frequencies in different populations as follows: Starting with African populations, and ending with the gnomAD ge nome database that gives general values for AFR (Africans), AMR are Latino-Admixed American. ASJ: Ashkenazi Jews. EAS: East Asian. FIN: Finns. NFE: non-Finnish Europeans, and OTH: unclassified, residual groups.

Amhara 37%
RHG 10%
Dizi 10%
Fulani 23%
Hadza ~0%
Herero ~0%
Ju|'hoansi 83%
Mursi 7%
Chabu 0%
Sandawe 23%
Tikari 0%
!Xoo 83%
gnomAD_genome_AFR 21%
gnomAD_genome_AMR 56%
gnomAD_genome_ASJ 71%
gnomAD_genome_EAS 39%
gnomAD_genome_FIN 83%
gnomAD_genome_NFE 80%
gnomAD_genome_OTH 73%

This seems a strange trait, absent in all of Africa (where dark pigmentation prevails, but present in San and all non-Africans. Note that ALL non-Africans have higher values than Africans except the San Koisan people. The Amhara of Ethiopia, have according to the paper "experienced strong non-African admixture (e.g., Amhara from Ethiopia)"

The paper goes on to descibe another allele, PDPK1, studying different SNPs along it, and noting that it regulates skin pigmentation (reducing the growth of skin-coloring cells called melanocytes, in mice). At one of the SNPs, rs77665059, the ancestral variant "C" (cytosine) is found at higher frequencies among the San people (67 to 83%) vs. other African groups (3%) and non-Africans (14%). "Individuals with the C allele have lighter skin pigmentation compared to individuals with the A allele in the San." Unfortunately, there is no data table to show its frequency in different populations. But from online databases, I prepared the following table (Source and Source)

Population       C (derived allele)
  Group              frequency  
Total Global    1.81%
European        0.75%
Azkhenazi Jews      1.03%
African          9.63%
African Others   10.5%
African American       9.6%
Asian          0%
East Asian          0%
Other Asian          0%
South Asian        0%
Latin American 1   3.3%
Latin American 2    1.21%
Other          1,88%

This is clearly a San, and African trait. Possibly originating from the ancestral archaic hominins. I would suggest that the high prevalence among some Latin Americans is due to the slave trade, that incorporated African genes into admixed Amerindian populations.

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

OOA Routes: Sicily Strait (Post 3)

This is the third post in my series on the routes that could have been used by ancestral hominins like Homo erectus and also by Homo sapiens to migrate out of Africa (OOA). In today's post we will look into the Strait of Sicily.

Post 1: Where was the Out of Africa Corridor?
Post 2: OOA Routes: Gibraltar
Post 3: OOA Routes: Strait of Sicily
Post 4: OOA Routes: Sinai
Post 5: OOA Routes: Bab-el-Mandeb

Strait of Sicily

Nowadays this corridor is dismissed and not even mentioned as an option for human migration out of, or into Africa (see Oppenheimer, 2012).

The strait separating Tunisia in Africa, from the island of Sicily, Italy, Europe, is a viable route for migration across the Mediterranean Sea from North Africa into the insular region of Italy, and then, crossing the strait of Messina (~3km - 2 mi) from Northern Sicily, accessing the tip of the Italian "boot" on mainland Europe.

The crossing, now used by illegal migrants into the European Union, is some 145 km wide (90 mi.) Too wide to see Sicily from Africa. However, there are some Italian islands in the strait: Pantelleria 77 km - 48 mi. from Africa and 104 km - 65 mi. from Sicily. It is 135 km (84 mi.) from Tunez to Lampedusa, another 44 km (27 mi.) to Linosa, and 122 km - 75 mi. to Malta and Gozo, from there to Sicily it is 85 km - 52 mi.

This is a wide strait, and would require navigation skills to cross it, with current sea levels. However, sea levels were far lower during the Ice Ages of the past 2 million years, and now submerged continental shelf areas were dry land at that time.

A 100 meter drop (330 feet) in the water level of the Mediterranean would have exposed banks that are now submerged, like the Adventure Bank, or Adventure Plateau, on the southern coast of Sicily, that spans 80,000 km² or 30,090 sq. mi. On this bank is shallow area known as Pantelleria Vecchia (Old Pantelleria) which can be seen in th following map, adapted from Galili, 1981. It shows the coast exposed if sea levels dropped 100 meters (black line).

A submerged 12-meter (36 foot) long megalithic monolith ( an obelisk-like stone slab) was discovered on the seabed at Pantelleria Vecchia, it weighs 15 tons, and now lies under 40 meters (120 feet) of water. This shows that neolithic people lived here when it was emerged land. Lodolo and Ben-Avraham, 2023 note that "seawater inundated the inner lands at 9350 ± 200 year B.P., the upper limit which can be reasonably taken for the site abandonment. This discovery provides evidence for a significant Mesolithic human activity in the Sicilian Channel region."

We know (see Scerri, 2025) that late stone age people crossed from Sicily to Malta some 8,500 years ago in simple boats. But, it could have been accessed on foot, as the continental shelf linking Malta to Sicily was dry land during the Last Glacial Maximum (25 kya). Neanderthal teeth were discovered in the Għar Dalam Cave, in Malta by Despott, and reported by Keith, 1918 (more on Keith further down). However, mainstream scholars say they are more recent, and belong to modern humans. The controversy lives on (read more.

Why cross the sea here?

From the coast of Tunisia, you can spot the volcanic summits of Pantelleria on clear days (see this image), which could have enticed ancient explorers to go there. From Pantelleria it is a short crossing to the then emerged Adventure Bank (36 km - 20 mi.)

Opinions against this corridor

Villa, 2001 summarizes the points against this corridor without completely disregarding it, as follows: "In view of the endemic faunas of the Lower and early Middle Pleistocene, the uncertain context of Lower Paleolithica artifacts, the absence of verifed reports of Mousterian industries in Sicily (Mussi, 1992, p. 288), the absence of human remains before the Upper Paleolithic, and the tectonic history of the island and adjacent areas, we must conclude that Sicily is unlikely to have been an important connecting point between Africa and Italy until the Upper Paleolithic." (highlighting is mine).

The French school of archaeologists was more favorable to this corridor. Henriette Alimen (1900-1996) propsed that Acheulean Africans reached Europe through Gibraltar and the Tunisia-Sicily Strait (Alimen, MH (1975). Les "isthmes" hispano-marocain et siculo-tunisien aux temps acheuléens. L'Anthropologie, 79 (3), pp. 399-436.

Rolland, 1992 is also cautious about "The Siculo- Tunisian landbridge" he regards the pebble tools and the matching Pebble-Culture in the Maghreb as unconfirmed, and notes that Italy's mainland was a narrow and complex geography that was subjected to great changes during the Ice Ages. Furthermore, the Mediterranean and the Alps tended to isolate it. The most likely route for entry into Italy, according to Rolland, was from the east, via the Adriatic and Ionian seas' shelves, as attested by Early Paleolithic sites in that region.

Nevertheless, there is evidence of Acheulean tools, 700,000 years old, from Notarchirico in Southern Italy, see Moncel, 2020, (highlight is mine): "the location of Notarchirico in southern Italy suggests two possible paleogeography-dependent routes: (1) following the northern coasts of the Mediterranean Sea from the Levant during low sea levels in glacial phases, or (2) crossing the Sicily channel between Tunisia and Sicily, also during glacial periods with low sea levels.Given the evidence of probable hominin occupation of insular land masses in the Mediterranean during the Lower Paleolithic (Crete, Gavdos, and Naxos), along withrecent discoveries of evidence of settlement on Indonesian and Philippine Islands east of the Wallace line in Southeast Asia as early as 700 ka, the Sicilian route deserves consideration, in spite of the absence of solid evidence of a land bridge."

The following map, from Depraetere, 2025 shows the region as it stood arond 20,000 years ago, with the emerged land, and modern shores (on the lower right side in color, are the shelve regions currently submerged):

Grimaldi Cave, and the Khoisan in Europe!

Keith, mentioned further up, regarding the Maltese Neanderthal teeth, believed that primitive Africans, related to the Bushmen (now known as Khoisan or San) reached Europe via Gibraltar or Sicily, and settled there, while Neanderthals and more modern-looking Cromagnons (anatomically modern humans) were native to Europe. The Grimaldi people were an example of the African branch. They discovered in 1901 by the Prince of Monaco in Mentone, Italy, (see Google map) at the lowest level of the Grimaldi Cave, were "of a race which was neither that of Neanderthal nor that of Cro-Magnon. The skeletons... present traits which have been interpreted as Negroid in character. It will be remembered that the Cro-Magnon race, with its Aurignacian culture, is supposed to have entered Europe from Asia by way of northern Africa and the old land-bridges across to Italy. Now in recent years there are coming to light all over Africa remains of a type of art, consisting mainly of engravings and paintings of animals, which in many ways recall the remarkable cave art of the Upper Paleolithic in Europe. In South Africa works of this character are attributed in part to those dwarfish, yellow-skinned, woolly-haired little hunters, the Bushmen, themselves undoubtedly a very ancient race, now nearly extinct. Moreover, cer- tain of the physical peculiarities of the latter people are shown clearly in the figures of very stout nude women, carved from ivory or soft stone, which have been found here and there in the Upper Paleolithic of Europe. These facts, taken in conjunction with the Negroid traits ascribed to the two Grimaldi skeletons just mentioned, seem to hint at some African influence on Aurignacian art. Any more definite conclusion than this, however, we should hardly be justified in drawing as yet." (see p. 78 in Bishop, 1930)

The Grimaldi man and woman, are from the Late Paleolithic and lived 22,000 to 26,0000 years ago. They were modern humans. It is interesting that these ancient modern humans in Southern Europe were assumed to be Bushmen, we know that Europeans share the same pale skin pigmentation that Europeans have (see post).

Some like Clyde Winters support interactions between Khoisan and Europe (see his comment on a formal paper) suggesting that the " southern African Khoisan (SAK) population... SAK people were the Grimaldi and Cro-Magnon people of Western Eurasia... By 70 kya Khoisan people probably spread hg N into West Africa... Sometime before 40kya there was probably a second migration event from Cameroon and possibly the Senegambian region into Northwest Africa on into Iberia." Hinting at a Gibraltar Crossing. Note that Winters is African-Centric and also supports an early migration of Africans, who peopled America.

Comments

I rate this corridor as unlikely, even though it is feasible. Perhaps future findings in Sicily will shed more light on the matter.

My next post (#4 in the series) will cover the Sinai, Northern Red Sea Route.

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

OOA Routes: Gibraltar (Post 2)

This is the second post in my series on the possible routes used by hominins (from Homo erectus to modern humans) for their out of Africa (OOA) migration, and, why not, for potential "Into" Africa migrations. Today's post covers the Gibraltar Strait.

Post 1: Where was the Out of Africa Corridor?
Post 2: OOA Routes: Gibraltar
Post 3: OOA Routes: Strait of Sicily
Post 4: OOA Routes: Sinai
Post 5: OOA Routes: Bab-el-Mandeb

Gibraltar

The Strait of Gibraltar is a narrow strait set between the southern tip of Spain and Gibraltar on the northern, European side, and Ceuta and Morocco on the southern, African side.

It is roughly 25 km long (16 mi.) and 14 km wide (almost 9 miles) and serves as a waterway linking the Atlantic Ocean on the west with the Mediterranean Sea on the east. It is quite deep, ranging from 300 to 900 meters (980 to 2,950 ft.)

Two tectonic plates meet here, the African and the European plates, and the movement of both plates led to the closure of an older strait that preceded Gibrlatar, the Betian Strait 5.96 Million years ago, sealing the Mediterranean off, cutting the inflow of water from the Atlantic Ocean. Evaporation over the next 600,000 years led to the drying out of the Mediterranean, with deserts and salt flats covering its barren former seabed (Messinian salinity crisis). Later, rifting along the plates' edges led to the formation of the current strait, and the catastrophic flooding that followed, refilled the Mediterranean basin (Zanclean Flood).

The strait is a continuous body of water, the coast of Europe can be seen from Morocco, and vice versa. Possibly enticing hominins to set out and cross it.

Tne idea was first suggested by Paul Pallary (1869-1942) in 1909, when he proposed that a type of stone industry was shared on both sides of the strait some 25,000 years ago, he called it "Iberomaurusian". This was taken up by Obermaier (1924) who applied it to a "Capsio Tardenoisian" culture, the former in Africa, the latter in Europe. In his work, Obermaier wrote: "Old Stone Age. First invasion — from Africa. The primitive Chellean and Acheulean industries in stone spread from Egypt over northern Africa and through Spain into western Europe. At a later cultural stage, the Mousterian, which constitutes a further evolution of the two earlier cultures (its beginning estimated at 40,000 B.C.), fossil remains of men of the Neanderthal Race are found in Spain, France, Belgium, Germany, Jugo-Slavia, and Czecho-Slovakia. The Heidelberg Race, remains of which are found in Germany, is probably ancestral to this race and may have been contemporaneous with the Pre-Chellean culture ; no trace of it has yet been found in Spain."

Spanish historian and archaeologist Luis Pericot Garcí in the 1940s and 1950s incorporated the notion to his Aterian (north Africa) and Soultrean (Europe) common culture he "organized a crossing of the Strait of Gibraltar by raft—a crossing that proved more difficult than anticipated and could not be completed. He even believed that connections might have existed between Africa and Spain as early as the Lower Paleolithic, a theory potentially supported by the presence of numerous cleavers and other Acheulean artifacts of African character in the Iberian Peninsula."

Finally, Henriette Alimen (1900-1996) explored the potential crossings from Acheulean Africa to Europe via Gibraltar and the Tunisia-Sicily strait.

Modern scholars do not agree with any of these theories.

Stepping stones for an easy crossing

The image above (Fig 2. in Gibert Beotas, 2003) displays the current coasts of Africa and Spain at Gibraltar, and how it would look with a lower sea level after it droped 150 meters (492 ft.) Islands appear on the western side of the Strait. Gibert Beotas calculates that the distance is reduced to half, from 14 km to 5 plus 2 km, island hopping.

Straus, 2001 noted that a lower sea level would make some of the seabed appear on the surface: "several small islands would appear within the Strait in the sector between Paloma Point and Tangiers whenever sea fell further than 100 m below its present level, making for several short water crossings, none greater than ca. 5 km if this (western) route were to have been taken. The distances would have been even shorter under full glacial conditions, with sea-level regression of 120-130 m"

Regarding the crossing, Flemming, 2003 points out that "To the west of the narrowest part of the Strait a group of substantial shoals become large islands at glacial low sea level, and these were visible vegetated land masses, completely changing the appearance of the Strait from either shore. The length of the Strait itself was increased, and the archipelago provided a stepping stone and safety net to anyone seeking to cross."

Straus cites (see the article here too) who suggested that Lower Pleistocene hominids like Homo ergaster could have crossed at Gibraltar around 1.8 to 1.6 Million years ago when it was only 6.5 km wide during the Aullen marine transgression.

Straus concludes that it is unlikely that early Homo crossed the strait put it is "somewhat plausible" but any later contact is discarded during the Middle Pleistocene. Only, during the Upper Pleistocene did modern humans cross the strait, navigating across it.

Proof

Gibert Beotas aruges that ancient stone tools discovered in Orce, South Eastern Spain (Andalusia), knapped using Oldowan techniques, and dated to 1.4 Million years ago, are possibly the work of hominins who used the Gibraltar crossing, instead of taking the longer route across the Levant, Anatolia, the Balkans and eastern Europe, central Europe and then into Iberia.

There is evidence of animals crossing the straits since Miocene times, a two-way exchange between Europe and Africa. Humans could have done the same. Another fact to bear in mind is that hominins did cross open stretches of sea to reach Luzon in the Philippines, and Flores in Indonesia.

Arribas and Palmqvist, 1999 (see the article here too) argue that "crossing large rivers and mountainous chains, with adaptations to different vegetation zones and to broader ranges of temperature and rainfall, and a simultaneous colonization of Europe through Gibraltar, perhaps Sicily, and the Eastern Mediterranean helps to explain the presence in several north circummediterranean sites of Spain (Orce), Italy (Pirro Nord), Greece (Apollonia)and Georgia (Dmanisi) of certain African species of large mammals which have not been found, at present, in Central Europe during Lower Pleistocene times, such as M. whitei, whose dispersal seems to have been limited up to the 40°N parallel"

They included the following map in their research paper:

Animals like wild boars found in North Africa and Spain share a common genetic origin. Soria-Boix, 2017 wrote that "Contacts across the Strait of Gibraltar in the Pleistocene have been studied in different research papers, which have demonstrated that this apparent barrier has been permeable to human and fauna movements in both directions. Our study, based on the genetic analysis of wild boar (Sus scrofa), suggests that there has been contact between Africa and Europe through the Strait of Gibraltar in the Late Pleistocene (at least in the last 90,000 years), as shown by the partial analysis of mitochondrial DNA. Cytochrome b and the control region from North African wild boar indicate a close relationship with European wild boar, and even some specimens belong to a common haplotype in Europe. The analyses suggest the transformation of the wild boar phylogeography in North Africa by the emergence of a natural communication route in times when sea levels fell due to climatic changes, and possibly through human action, since contacts coincide with both the Last Glacial period and the increasing human dispersion via the strait."

Last July I posted about The common ancestor of Denisovans, Neanderthals and Humans, citing a paper by Hublin, 2026 who mentioned that "The Spanish and Moroccan fossils share several features in their teeth and mandibles. Both groups display a combination of archaic and derived features reminiscent of later hominins... These similarities revive the question of possible exchanges across the Strait of Gibraltar during the EP."

Comments

The crossing is feasible, short, and was done by animals over the course of the past few million years. There are fossils in Spain and Morocco that suggest an exchange between Africa and Europe (possibly both ways). This could be one of the corridors used by hominins to people the world either from Eurasia into Africa, or the other way round.

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

Where was the Out of Africa corridor? (post 1)

The African origin of modern humans, and all hominins (including Homo erectus and other Eurasian hominins) implies that they originated there, descending from the great apes of that continent (i.e. Chimpanzees) and later migrated out of Africa into the Old World, and much more recently, via Berigia, into the Americas.

But, which was the course the ancient hominins that led to erectus, the later ones leading to Neanderthals and Denisovans, and finally those leading to us, took to move out of Africa? Which was the route?

In fact there is no certainty on this matter, and more than one route have been proposed for the Out Of Africa migration. These routes are shown below, in a map of Africa and the closest points that separate it from Eurasia. These are, from west to east, Gibraltar, the Strait of Sicily, Sinai, and Bab-el-Mandeb Strait.

The "out of" and "into" Africa routes for hominin migration. Copyright © 2026 by Austin Whittall

These routes were proposed by anthropologists because they are feasible. It is easier to cross 10 km of water via Gibraltar, where you can see the European coast from Morocco in North Africa than setting sail from Egypt northwards into an open sea without knowing what lies ahead. This can be said about the other two crossings (Straits of Sicily and Bab-el-Mandeb), where the stepping stones across the Red Sea and the Mediterranean are visible from the coast of Africa.

Feasibility also implies that the water can be navigated. In fact, Homo erectus crossed open stretches of sea 800,000 years ago in Indonesia, and also to reach Crete. This suggests that they had seafaring abilities.

Another factor is that animals seem to have been able to negotiate with these sea crossings, so one would expect humans could do the same.

The final argument is the similarity, or continuity of certain stone knapping technologies on both sides of the gap, suggesting a population bridging the gap during a migration. This is something seen in the Levant, where archaics and even modern humans are found in Israel (Levant).

Two way routes

The fact that they were used to exit Africa (the articles I cite are all formal ones, and they uphold the African origin of hominins and modern humans) does not mean they were used in the opposite direction, for "Into Africa" migrations.

Neanderthal alleles have been found in Africa, sourced from Eurasia; and it is possible that Homo erectus originated in Eurasia and migrated into Africa, or that modern humans did the same, peopling Africa. It is possible that the common ancestor of chimpanzees, gorillas, and all homo species originated in Eurasia.

Over the next posts, I will describe each of these corridors, Gibraltar, Strait of Sicily, Sinai, and Bab-el-Mandeb.

This Series of Posts comprises the following posts

Post 1: Where was the Out of Africa Corridor?
Post 2: OOA Routes: Gibraltar
Post 3: OOA Routes: Strait of Sicily
Post 4: OOA Routes: Sinai
Post 5: OOA Routes: Bab-el-Mandeb

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

Bushman Canine

The Bushman Canine is an unusual dental feature that was first observed among South African Bushmen (San, Khoisan people) by Oranje in 1934, and Galloway in 1937. The name was coined by David R. Morris in 1975. Its more formal name is "Canine Mesial Ridge", as it is known in the Arizona State University Dental Anthropology System (ASUDAS).

Since it is found at very high frequencies among the San people, and they are presented as the most diverse, divergent, and "oldest" living branch of the original African modern humans, this trait could probably shed some light on the origin and dispersion of our Homo sapiens lineage.

The Bushman Canine

Canine teeth are located on both upper and lower jaws, on each side of the incisors. They have a fang-like appearance, and are the teeth with longest roots. They are designed to seize, tear, and cut food.

Canines with the Bushman canine trait have a different shape, they resemble the premolars. Below is a depiction of a Bushman canine; the image comes from Irish & Morris, 1996:

Prevalence in different populations

This trait is found among the Khoisan, the allegedly "oldest" and most diverse human group, who live in Southern Africa. But it is also found in other populations around the world.

The following image gives the values for African populations, those closest, geographically, from the San Bushmen people. It shows the frequencies of incisor shoveling (see my post on dental shoveling), and Bushman Canine in African populations, from Irish, 1998, Table III.

As you can see, within Africa, there is a large variability in frequency, even in areas close to each other like Western Africa where it varies from 0 in Congo, to 35% in Togo Benin, with 6 or 7% in Gambia and Ghana.

Its frequency, according to Bailey, 2006 and (Sakuma, 1991), in other populations is the following: 0% in early Africans, modern Europeans and modern Asians, Indians, Polynesians, and Native Americans. But it reached 20% in Homo erectus, 33.3% in Early Neanderthals, 57.1% in late Neanderthals, and 16.6% in Upper Paleolithic Europeans.

This makes me wonder if its presence in ancient Europeans stems from Neanderthal or Denisovan introgression, or possibly a trait that is ancestral, and inherited from erectus.

In other populations, Irish, 1998 found the following frequencies for Bushman Canine: Sub-Sahan Africa: 18.1% ; North Africa: 6.1%; Europe: 4.8%; Sundadonts: 2%; Sinodonts: 1.2%; Australia: 5%; Melanesia: 3.2%.

Irish, 2026 reports it at 0% frequencies in Pima (Native Americans), Lower Ob Khanty (West Siberia), Aleutians, Chuckchi (Siberia), Vietnam, Philippines, Australia (North), Nepal, Italy, and South Finland; and at low frequencies elsewhere: Kazakhistan 2.4%, Monglolia 3.7%, Thailand 9.3%, Japan 4.7%, Malaysia 4.3%, Borneo 11.1%, New Britain (Melanesia) 1.9% Greece 8.7% Estonia 2.7% Lapps (Finland) 4.2%. (See Table S2 in that paper's supplementary material).

Hotspots with high frequencies Outside of Africa

The "Non-African" values mentioned above are all lower than 10% (except for Borneo). Interestingly, it has been reported at rates of 14% among inhabitants in Kerala and Odisha, in India (Nair, 2020). Very high frequencies were reported among Central American natives by Scherer, 2004, who studied Maya dental traits from the Classic Period (AD 250 to AD 900) and found a 7.1% frequency, which is high, some sub-populations like those at Barton Ramie, Aguateca and Seibal presented prevalences of 25% to 36.4%. These values are also mentioned by Domínguez Vázquez, 2020 in his thesis (see Annex 4, p.162). He reports it at 57.1% frequency among Yucatan pre-Hispanics, 100% among Yucatan pre-ceramic people (by pre-ceramic he means 4,500 to 12,000 year-old specimens) yet absent among Mexican and North American pre-ceramic populations, and 100% in Zhoukoudian, China humans, 35,000 years old.

The Sub Saharan San (Khoisan) Bushmen

But, why is it found among San people at frequencies of 43.1%? (Sakuma, 1991) There has been no Neanderthal introgression into Africa. Did erectus migrate into Africa, carrying it? Or, is it an ancestral trait that has not been lost over the course of hundreds of thousands of years?

These people have some odd ancestral traits, including the epicanthic fold, shared with Asians, pale skin pigmentation, shared with Europeans, they also display moderate dental shoveling, a factor which Nair, 2020, found as strongly associated with Bushman Canine among Indian populations, which hints at some kind of genetic link between both dental traits.

Back in 2018, I posted about research describing teeth recovered from a human who lived in Magubike, Tanzania, 45,000 years ago. The remarks were that they had Neanderthal and H. erectus traits. I revisited the post today, and reread the article by Willoughby et al., 2018 and noticed that its Table 11 reported that this person had Bushman Canine trait, and added that it was not present in other Mid to Late Pleistocene African fossils yet present in 20% of the Early Holocene Kenyan ones.

The paper also reported that the teeth had “Khoisanoid affinities” (due to the presence of the Medial Canine Ridge found in the San people, among other traits), yet these teeth were big, and had some traits that are not found in archaic Homo sapiens or H. heidelbergensis or other hominins from that period.

This seems to imply the presence of other unknown hominins in Africa admixing with the Khoisan people, super archaics? These could be related to the Homo erectus lineage, or relatives of Neanderthals / Denisovans. This could explain the high frequencies in India and Borneo, possible spots of Denisovan-human admixing. And, regarding America, I have already posted about human-Denisovan admixure in America.

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

Shoveled incisors an ancient hominin trait

Teeth shapes are a useful tool to identify the fossil remains of hominins. Neanderthals, Homo erectus, and modern humans have distinct teeth shapes (mass, multiple roots, shoveling, cusps, protrusions). Even people living in different continents have specific teeth shapes.

Dental Shoveling

One type of tooth shape is known as dental shoveling, where the front teet, known as incisors, instead of being flat on their inner side, are shoveled. This type of shoveled teeth has been observed in monkeys such as macaques, baboons, and gibbons. It is also found in contemporary and ancient humans, as well as hominins.

Hominins with shoveled incisors

Our hominin ancestors also displayed shoveled incisors: it has been found in ancient remains of Australopithecus, Homo erectus, and the fossils from Dmanisi, Georgia and Atapuerca in Spain (Homo georgicus and Homo antecessor). More recent, yet ancient specimens include Neanderthals ad of course, remains of Homo sapiens (Denton, 2011; Margvelashvili, 2008).

Shoveled incisors in contemporary populations

Among our lineage, Homo sapiens, modern humans, shoveling is found at vry higher frequencies in East Asians (Japanese, Chinese, Mongolians, Northeastern Siberians) and populations that originated in Northeast Asia like the Eskimos and North American Native Americans, and the South American natives who replaced the older, ancestral Paleo Indians in that part of the Americas. Surprisingly, the Khoisan in Southern Africa have shoveled teeth.

Other ethnic groups have very low frequencies or absence of shoveled teeth: the paleo-Indians in South America, South and South Eastern Asians, Melanesians, Europeans, Arabian and Middle East populations, North Africans, central Africans, Eastern Africans.

Below is an image showing a normal, and a shoveled tooth (from Benton), it cleary shows the difference in incissor shape due to shoveling.

A table with frequency of shoveling, and source

• 100% (Source) Mongolia
• 100% (Source) China
• 64.7% (Source) Ainu, Sakhalin
• 93.4 % (Source) Japan, Tokyo
• 23.8 % (Source) Tajik, Afganistan
• 6 % (Source) Philippines
• 87.3 % (Source) Polynesian, Easter Island
• 60-90 % (Source) Australian Aboriginal
• 73% (Source) Melanesian
• 98.3% (Source) Pima Native Americans
• 100 % (Source) Yanomana Native Americans, Amazonia Brazil, Venezuela
• 100% (Source) Northwest Argentina (Amerind, mestizo)
• 90.1 % (Source) Precolumbian Peru
• 49.5 % (Source) Lapps in Finland
• 9.4% (Source) England
• 20.1% (Source) Denmark
• 40.2 % (Source) Germany
• 10.3 % (Source) Uganda
• 24 % (Source) Egypt
• 20 (Source) Sudan
• 31.2 % (Source) Punjab, Pakistan
• 22 % (Source) Odisha, East Central India
• 15 % (Source) Kerala, Southern India
• 95.5 % (Source) Mysuru, Southern India
• 8 % (Source) Tamil population in Southern India
• 9 % (Source) Pakistan
• 5 % (Source) Syria and Jordania
• 20 (Source) Yemen
• 9 % (Source) Saudi Arabia
• 10.1 % (Source) Turkey Black Sea region

The variability of frequencies is notable, even within the same region (see India for instance). Amerindians and NE Asians have extremely high prevalence of shoveling. There is a cline from East to West across Eurasia, but even in SE Asia and Australia, frequencies are high.

Not all shoveling is the same

Shoveling in Neanderthals, erectus and modern humans differ in shape, and is probably driven by different genes. In this sense Yuan, 2019 notes that "The type of shoveling teeth found in Neanderthals and Pleistocene Homo from Atapuerca-Sima de los Huesos may either be a different type from that of Asians and Africans or come from early dispersal of Homo from Asia to Europe."

But which genes are involved, or if there is an interplay of several, is a mystery.

Kimura, 2009 reported that the Ectodysplasin receptor Gene (EDAR) in its "EDAR 1540C alleles... was strongly correlated with the tooth-shoveling grade... The effect of the allele was additive and explained 18.9% of the total variance in the shoveling grade." But it seems that other alleles are involved in shoveling. Interestingly EDAR 1540C is absent in Africans, Denisovans, and Europeans (where shoveling is low) and high in East Asians and modern Amerindians.

Who has shoveled teeth? Frequencies

Bailey, 2006 provides some frequencies on incisor shoveling in different populations: 100% in Homo erectus, early Neanderthals, and late Neanderthals. At 33.3% in Early Africans and Modern Asians, 45.5% in Upper Paleolithic Humans in Europe, and 37.5% in modern Europeans.

Denisovans, in the only incisor found to date, from the Xujiayao specimen of North China, 220,000 to 160,000 years old shows "marked shovelling." (Xing, 2015 in Masojc, 2026).

Interestingly, Yuan, 2019 notes that "native Africans such as Khoisans are well known to have certain East Asian features such as shoveling teeth, epicanthic fold, and lighter skins." The Khoi are said to be the most diverse and divergent, and therefore the most ancestral lineage of modern humans on the planet. But no Neanderthal or Denisovans have been found in Africa, and admxiture there between the ancestors of the San and the Neanderthals and Denisovans is not believed to have happened.

Comments

There are several genes that regulate teeth shape (Qing, 2025), making it a "polygenic" trait.

Shoveling has been linked to one variant of the EDAR allele (I have posted about it and its presence in Asia and the Americas).

Research by Kaya and Merriwether, 2024 has shown that Shovel Shaped Incisors (SSI) and Carabelli's Cusp (CC) are both linked to other genes: "Fifteen SNPs/s belonging to SOSTDC1, FGF3, FGF4 and WNT10A were significantly associated with SSI and/CC expression." So there are several genetic drivers for shoveled teeth.

Regarding the EDAR variant in Amerindians and Asians; did it arise spontaneously as a mutation in modern humans in Asia and then spread in Northern and Eastern Asia, and the Americas?, or was it introgressed from other hominins living in that region, like Homo erectus or the Denisovans?

Also, why do the San people of South Africa have shoveled teeth, even though there is no known introgression of Neanderthals, Denisovans or erectus in that region? Is it an ancestral trait found in archaic hominins which admixed from ghost African populations? The lower frequency in Europe and Western Asia, as well as North Africa suggests that there were hominin populations which lacked the shovel teeth alleles. This suggests, in my opinion, that it is possibly a modern human trait, and that shovel teeth introgressed from other hominins in Central or Eastern Asia (Neanderthals, Denisovans, or erectus), and back migrated from there into Europe, Western Eurasia and Africa.

A very interesting and thorough article published in 1985 by Yuji Mizoguchi "Shovelling: A statistical analysis of its morphology" suggests that shoveled teeth are stronger than regular non-shoveled ones and that the hunter-gatherer lifestyle selected in favor of strong faces able to "resist powerful biting forces, and one of the causes of the need for such a powerful biting mechanism was possibly hunting activity directly or indirectly associated with heavy meat-eating."

Misoguchi distinguishes three kinds of shoveling:

(1) weak or moderate, with "a slightly swollen basal part of the lingual surface of the tooth crown and lingual marginal ridges converging towards the cervix" Found in the ancient australopithecus and in almost all contemporary humans. This one continued to exist in Africa since the Australopithecines, and is found in modern Africans. Found in modern Asians and Europeans too.

(2) strong, with highly develped parallel ridges on the teeth's margins "a very deep lingual fossa and a large lingual tubercle." Found among East Asian Neanderthals and Homo erectus. Western Eurasian Neanderthals had a blend of types (1) and (2).

(3) strongly marked shoveling but the marginal ridges converge on the cervix. Lacking a "developed lingual tubercle" The tubercle is different from that of erectus and Neanderthals. Found among Innuit, Native Americans.

With these three varieties in mind, the evolution and dispersal of shoveling is the following, according to Mizoguchi>

"In Africa, the first type of incisor has continued since the emergence of the hominid, In Europe, the first type changed to the second type before or at the stage of Neanderthals, and, later, back to the first type. In Asia, as in Europe, the second type once changed into the first type after the Neanderthal stage, but some Asian anterior teeth developed in a different way from before, presumably as a result of direct or indirect adaptation to a severely cold environment. Such incisors are the third type of incisor observable in the modern inhabitants of the Arctic and Americas."

Perhaps the sequence is (1) ancestral African, evolved into a derived one, (2), in Homo erectus in Eurasia and later retained in Neanderthal. Those who would later become modern humans retained the ancestral version, globally, and the (3) variant appeared in East Asia, possibly from admixture with Denisovans.

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

Denisovan stone tools reported in a paper published in Nature

A second article published yesterday in Nature (Ruan, Q., Li, H., Xing, S. et al. Denisovans from southwestern China and their subsistence strategies. Nature (2026). https://doi.org/10.1038/s41586-026-10997-4) (first study mentioned in this post) investigated the stone tools and bones with cut marks found in the sediments of the excavation at Bianfu Cave, Yunnan, China. These were Denisovan tools. Some of which are depicted in the image below.

Figure 2, showing some Denisovan tools. Ruan et al., 2026

This group of Denisovans lived in an area that at that time was forested, and they hunted big game like water buffalo, and gaur (an animal resembling a bison), also deer (sika an red). Their tools were made from local stone and bone, and were not very elaborate.

1,366 stone artifacts were unearthed, and rougly two thirds of them were made from sandy mudstone. sourced locally they are not simple, but they are not sophisticated either. The authors write: "The core assemblage primarily reflects expedient flaking strategies, with generally low reduction strategies. Simple unifacial cores dominate, followed by bifacial cores... the retouch intensity of tools is low." This type of stone technology is found across the whole excavated period, stable over a period spanning from 167,000 to 134,000 years ago. They also found seven bone tools at the site.

The authors note that the tools "lack diagnostic Middle Paleolithic markers, such as Levallois technology and instead reflects predominantly expedient strategies in core reduction and tool production" It is similar to the Baishiya Karst Cave, in Tibet, where DNA identified the famous Xiahe mandible as Denisovan (a site that is 160,000 years-old). The bone tools are very similar to Neanderthal ones, suggesting that bone tool use was widespread, and also, hinting at adaptability and similar cultural behavior in both groups.

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

Denisovan skull bone, forearm and teeth found in Yunnan, China

A new paper published in Nature today (Rao, H., Xing, S., Ruan, Q. et al. Ancient proteins identify various Denisovan remains from Southwest China. Nature (2026). https://doi.org/10.1038/s41586-026-10976-9) reports discovering Denisovan fossils 167–134 thousand years old, in Bianfu Cave in Yunnan, China. The researchers sorted through, analyzing DNA, over 60,000 bone fragments.

Their analysis placed the specimens on a phylogenetic tree on the branch next to Denisova 3, a distinct branch from Neanderthals and modern humans. The skull bones were found to be similar to European Homo heidelbergensis, assumed to be the common ancestor of Neanderthals, Denisovans, and us, modern humans. The forearm is interesting because it is closer to the radial bones of modern humans and erectus than to African specimens like Australopiths (Sediba, Afarensis), or even Neanderthals.

A second paper was also published describing their tools! (posted separately).

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

The hard facts: ancient DNA: Lacking in Africa, present in Eurasia

When they discuss the Out of Africa (OOA) theory, scholars use DNA samples taken from contemporary, modern, existing populations, and add some (very few) ancient DNA samples to the dataset. However, are we certain that the modern genetic landscape reflects events that happened 60,000 to 100,000 years ago (60-100 ky)? And, more importantly, how old are these "ancient" DNA samples, belonging to ancestral humans.

DNA decays as time passes, the chemical bonds in the molecule break down due to the action of water, oxygen, temperature, and the pH of the soil in which the remains were preserved. So, we have relatively few samples of ancient modern human DNA. These "oldest" ones are: the Ust'-Ishim DNA from a man who lived in what is now western Siberia, Russia, around 45 ky ago. This is the very oldest of all specimens. The oldest East Asian sample is from Tianyuan, China, close to modern Beijing, roughly 39 to 42 ky old. In Europe proper, the sample from Czechia known as Zlatý kůň which are said to be 45 ky old (more on its age below). But, what about Africa, the purported cradle of mankind? The oldest DNA sequenced in Africa is roughly 18,000 years old, and comes from the Mlambalasi site, in Tanzania (source), the dates are not direct radiocarbon ones, but "...well constrained to the Late Pleistocene based on multiple indirect dates" Not so old after all!

Why is this relevant? The importance of ancient samples is that these people harbor, at least in Eurasia, Neanderthal admixture, at higher levels than current populations (as they were closer in time to the admixture event, and also, because depuration of harmful introgressed alleles hadn't had much time to take place). They also carry signals that were lost in later populations. But, in the case of Africa, we are lacking really old DNA, so all arguments about "diversity", "divergence" and distinctness are based on modern, living Africans. These contemporary people could have undergone admixture events with archaics, suffered selective adaptation, accelerated mutation rates over the past 45 ky, that altered their genetic makeup, so current comparisons may be misleading.

A look at the really ancient DNA in Eurasia

Eurasia has provided several samples older than 35,000 years and the DNA extracted from these individuals has paint a complicated migration process out of Africa. I can only imagine what surprises really ancient DNA samples from Africa would reveal.

A five-year-old paper, published by Prüfer K, Posth C, Yu H, et al., titled A genome sequence from a modern human skull over 45,000 years old from Zlatý kůň in Czechia (Nat Ecol Evol. 2021 Jun;5(6):820-825. doi: 10.1038/s41559-021-01443-x. Epub 2021 Apr 7. PMID: 33828249; PMCID: PMC8175239)🔓, reports the genetic makeup of the oldest European modern humans. Of course, as with all genetic publications, the Out Of Africa event is taken for granted and buttressed by each additional paper (even when there is no direct link between OOA and the study in question).

In this sense, this paper explains that "Modern humans expanded into Eurasia more than 40,000 years ago following their dispersal out of Africa. These Eurasians carried ~2–3% Neanderthal ancestry in their genomes, originating from admixture with Neanderthals that took place sometime between 50,000 and 60,000 years ago, probably in the Middle East. In Europe, the modern human expansion preceded the disappearance of Neanderthals from the fossil record by 3,000–5,000 years." In one streak they constrain the date of human expansion into Europe and Asia to 40 ky ago, and limit the admixture with Neanderthals to the Levant, ~50-60 ky before they expanded across Eurasia.

Interstingly this woman from Zlatý kůň "...belonged to a population that appears to have contributed genetically neither to later Europeans nor to Asians". A lineage that became extinct.

In this, she wasn't alone. The Ust'-Ishim person has no direct descent among contemporary Eurasians. This lineage also died out.

Another population, identifided by three individuals 42,580 to 45,930 years old, discovered in Bacho Kiru Cave, Bulgaria didn't contribute to the later European populations either, however they "are more closely related to present-day and ancient populations in East Asia and the Americas than to later west Eurasian populations." (Hajdinjak, 2021). They shared alleles with Oase 1, ancient Siberians, Native Americans, and the Far Eastern, 40,000 year-old Tianyuan man from China (who also shared his alleles with other populations: Amerindians and modern Asians).

This suggests a pan-Eurasian population of modern humans, spanning the continent from the Balkans to Eastern China (Oase 1, Tianyuan and Bacho Kiru are samples from it) with high levels of Neanderthal ancestry as we will see below.

The authors discuss the levels of Neanderthal introgression in Zlatý kůň and note that even though it is found at ~3%, similar to other specimens, like Ust'-Ishim (Note, however, that an old specimen from Europe, Oase 1, 40,000 years old, has two to three times those levels: 6 to 9% Neanderthal admixture) these are longer chunks, so they take this to signify that these segments didn't have time to break down into smaller segments (they are longer than those found in similar-aged Ust'-Ishim). This fact leads them to conclude that "... this individual from Zlatý kůň is one of the earliest Eurasian inhabitants following the expansion out of Africa". As you can see, this assumes OOA is a fact. Let's get some details.

Age of Zlatý kůň

When the remains of this woman were found, they were estimated to be 30,000 years old based on faunal remains and stratigraphy. However, radiocarbon dating gave much younger dates!: "direct radiocarbon dating resulted in a much younger date of ~15 ka (12,870 ± 70 years bp; GrA-13696)... In an attempt to clarify [its] ... age... , we radiocarbon dated a cranial bone fragment, resulting in a significantly older date of ~27 ka (23,080 ± 80 years bp; MAMS-36077)... A third date, ... produced a younger date of ~19 ka (15,537 ± 65 years bp; OxA-38602)." These young dates were attributed to contamination so they tried another method and tested an amino acid (hydroxyproline) from the bone collagen. It gave them a similar (young) date of ~34 ka (29,650 ± 650 years bp; OxA-38022). Finally (seeking something to provide a really older date) the authors used a phylogenetic tree by comparing the mt DNA from the Zlatý kůň woman, and assigned it to haplogroup N and comparing it to mtDNA from the Bacho Kiro site in Bulgaria (43 to 47 ky old) they reckoned that this fossil was roughly 43,000 years old (31.5–52.6 ky). It had to fit, by hook or by crook. So they got the old date they were looking for.

The Neanderthal "twist" to obtain an even older age

The oldest samples of DNA with Neanderthal admixture in Eurasia are, the Oase 1 (40 ky), Ust'-Ishim (45 ky), and this Zlatý kůň ("45 ky"). The level of Neanderthal introgression in other old remains from Eurasia are around 3%. All, except one, Oase 1 who lived 40,000 years ago, had a very high Neanderthal component. The authors try to explain this fact away: "Oase 1 carried more Neanderthal ancestry (6–9%) than other modern human genomes sequenced to date, owing to admixture with Neanderthals that occurred within the six generations before the individual lived."

The paper reporting Oase 1 gave (see Table 5) its average Neanderthal content as 7.11%, Ust'-Ishim as 3.08%, Kostenki 14 as 2.18% (Romania, 37 ky old), The Bacho Kiro ubduvudyaks carried 3.8%, 3.4%, and 3.0% respectively. Finally, Tianyuan, in China carried 4% to 5% (Yang, 2022) of Neanderthal alleles.

Compared with these, the 3.2% of the Zlatý kůň is normal and there is nothing unusual about it. So the authors tried another track.

They found that "Zlatý k&367;&328; shares more alleles with Asians than with Europeans." Which is not unusual all of these ancient Europeans are part of a pan-Eurasian population. But they explain it differently: modern Europeans originated in a "deeply divergent out-of-Africa lineage referred to as basal Eurasian" found mainly in the Caucasus, Levant and Anatolia. While all ancient European specimens don't carry any traces of this lineage.

Basal Eurasians

This population somehow did not admix with Neanderthals, and later replaced all of the ancient populations (those carrying high Neanderthal admixture).

The Basal Eurasian ancestry is strange; it carries "... little if any Neanderthal admixture and... separated from other non-African lineages prior to their separation from each other" (Lazaridis, 2016) because they split "from other Eurasians before the latter received Neanderthal gene flow" (Feldman, 2019)

So there is a population that left Africa and never mixed with Neanderthals (Basal Eurasians), one that moved into Europe and Asia, all the way to China (Zlatý kůň, Ust'-Ishim, Oase 1, etc.) mixing with Neanderthals, but they did so before the rest of the Out of African population moved east and north into Eurasia. Complicated scenario.

The authors argue, based on their data, that "Zlatý kůň falls basal to the split of the European and Asian populations... This suggests that Zlatý kůň was part of a population that split earlier from the population that later gave rise to Ust’-Ishim and other Eurasian populations."

The longer vs. shorter "chunks" of Neanderthal DNA found in Zlatý kůň is used as an argument to support its older age, and closeness to the Neanderthal introgression, but there are factors that could cut the admixed DNA into smaller pieces beyond recombination caused by the passage of successive generations. For instance, natural selection could have maintained long segments in Zlatý kůň because they provided an adaptative advantage, or these people were part of a larger population, which reduced the impact of genetic drift and segment shortening.

Veller, 2023 notes that demography also influences recombination (shortening of introgressed segments), populations don't admix in an instantaneous pulse, they mate over time, and mates are not randomly assigned, they may be chosen (non-randomly, or "assortative mating) and this reduces recombination's effects and the purging, or loss of introgressed segments. Choosing a mate with similar ancestry adds introgressed segments to the mix, reducing recombination and segment shortening. This effect could have acted among the people at Zlatý kůň preserving longer segments and causing the impression that they are older, when, in fact, they are not.

Comments

Out of Africa is painted as a simple migration that caused loss of genetic diversity due to founder effect and bottlenecks followed by admixing with Denisovans in the East, and Neanderthals in the West. As we have seen, this picture is oversimplified. The intermingling of ancient Eurasian lineages and modern humans were complex, with extinctions of local populations (this paper adds that the replacement of the original Eurasians by the Basal Eurasians was probably due to a massive volcanic event c.39 kya that altered the environment in Europe, the Campanian eruption, in Naples, Italy).

Africa, on the other hand has few, and very recent DNA samples. The discovery and analysis of older samples will surely make us rethink the Out of Africa theory and the origin of moden humans.

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Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia Copyright 2009-2025by Austin Whittall © 

Cranial shapes, OOA, Denisovans, Melanesians & Australians

A research paper published back in 2022 (Matsumura, H., Tanijiri, T., Kouchi, M. et al. Global patterns of the cranial form of modern human populations described by analysis of a 3D surface homologous model. Sci Rep 12, 13826 (2022). https://doi.org/10.1038/s41598-022-15883-3), compared the skulls of contemporary human populations from Africa, Europe, Asia, Americas, Melanesia-Australia, etc., finding some interesting traits.

Modern human skulls differ

The paper relies heavily on PCA data, which, as per my last post, may not be the most suitable tool to emply in studies like this one, which is, basically, morphometric, as it compares skull dimensions and reduces these different data values into several Principal Components).

The PC4 and PC2 (principal components 2 and 4) analysis shows that there are distinct groups: Africans overlapping Australo-Melanesians (see the lower image below, pink and red ovals on the right side), Northeastern Asians (green oval, bottom left), and Europeans (blue oval, top left). There are other populations as you can see in the upper image (Middle East, South Asians and Americas), but they are not shown as distinct groups in the second, lower, image.

Scatter scoring diagrams of PC2 and PC4 for cranial individuals from nine geographical units (upper), and four geographical units (lower), color maps of cranial surface highly correlating vertices to each PC. Fig 4. in Matsumura et al., 2022

Australo-Melanesian skulls are similar to African ones

The grouping toghether of two populations separated by an Out of Africa (OO) walking distance of 20,000 to 24,000 km (12,000 to 15,000 mi.) is indeed surprisin. But the authors point it out: "Australo-Melanesian (including Papuan) samples exhibited a closer resemblance to African samples than any other geographic series in the PCA of the homologous model." And they also explain it as if it was a normal consequence of such a vast trek: "This finding supports the hypothesis that the first dispersal group of AMH along the southern rim of Eurasia was of direct African origin."

But, if, as we now know, that Papuans and Melanesians have the highest levels of Denisovan admixture of all the global populations. Why would they carry 5% of Denisovan genes and still display a skull shaped like an African?

The paper states that Australo-Melanesians have a "large" AUC, comparable to Sub-Saharan Africans which also have large AUCs. They also share (this is the dimension marked by the PC2 axis) a "relatively longer neurocrania than the others... which describes the close affinity between the proportionally elongated crania of Australo-Melanesians and Africans and dissimilarities with the globular crania of some Europeans and Northeast Asians." Note that AUC is a metric (Area under the curve —AUC, in an ROC Receiver Operating Characteristics Analysis. A lot of jargon!)

The paper includes many comments on the differences between modern human skull shapes, and when it comes to the Australo-Melanesians explains it as follows. The authors mention the possibility of two OOA events, an ancient one, some 177,000 years ago, which led to anatomically modern humans out of Africa and into the Levant and Mediterranean basin, but whether these people expanded into Eastern or Southern Asia is still unknown. The other option is a recent wave (60,000 years ago) out of Africa along the Indian Ocean coastal regions towards Southeast Asia, Papua, and Australia. This was followed by other waves into North-Central Asia and Europe.

The paper adds that the similar appearance of African and Papuan-Australian crania was the result of this first migration along the Indian Ocean, which "...was of direct African origin, without significant morphological alterations in accordance with a particular climate or other substantial conditions" (they note the climate, becaus the attribute the shape differences of other humans to adaptation to colder climes).

Denisovans

Denisovans admixed with Melanesians, and Papuans exhibit a high proportion of Denisovan alleles. Denisovan skulls are very different from ours (Source) but they are do have a long skull like Austro-Melanesians: "...long and low cranial vault, a wide and low face, large and almost square orbits, gently curved but massively developed supraorbital torus, flat and low cheekbones with a shallow canine fossa, and a shallow palate with thick alveolar bone supporting very large molars."

But, Denisovans are Asian hominins, they never entered Africa. So, why do Africans share this long skull too?

Controversial pro-China, sinocentric scholar Shi Huang argues that the OOA theory is wrong, ant that "An alternative worth testing is my proposal that Australo-Melanesians, including Papuans, retain unusually high Denisovan ancestry, and that Denisovans ultimately trace to an African-related archaic lineage. Under that model, the otherwise striking African–Australo-Melanesian cranial affinity could reflect shared archaic ancestry rather than simply an early modern-human migration out of Africa."

Reasonable. Neanderthals and Denisovans are said to have split from the modern human lineage within Africa, exiting the continent around 600,000 years ago. Denisovans are not supposed to have back-migrated into Africa. Probably the human group that led to Australian and Melanesians carried a higher content of pre-split alleles than other humans who moved north into western Eurasia.

Another possibility is that humans originated in Eurasia, and migrated from there. One group, with the Australian-Melanesian trait moved into that region and also into Africa. Another moved north into Siberia, and west, into Europe. Why should we constrain our theories to the OOA one?

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