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