Between 800,000 and 900,000 years ago several hundred individuals, perhaps thousands, lived in the Burgos mountain range of Atapuerca. There they became hunters of deer, equids and large bovids, while at the same time they hunted down carcasses of mammoths and rhinoceroses. They also collected fruits such as hackberry, a very sweet berry that grew along the slopes, and which they ate after practicing cannibalism. It was Homo antecessor (in Latin, “the pioneer man, explorer”), an extinct species that roamed the world almost a million years ago.
The teeth found in 1994 in Atapuerca are considered one of the oldest human fossils found in Europe to this day. Thanks to paleoproteomics, that is, new techniques to analyze the proteins of bones and teeth, we know that the two teeth that archaeologist Aurora Martín Nájera found on July 8, 1994, digging into the clay soil with a screwdriver and a brush, belonged to a human population from the Early Pleistocene.
Those incisors were neither deer nor bear, but human. “We express our happiness by doing the beetle, lying on our backs and kicking the air with energy,” say José María Bermúdez and Eudald Carbonell, co-directors of the excavations in the Atapuerca mountain range, in the entertaining book they have just published, Homo antecessor. The birth of a species (Criticism).
The work intersects the personal stories of those who participated in the discoveries that ended up changing the evolutionary history of humanity and the scientific achievements that led to writing in gold letters one of the most brilliant pages of Spanish science.
While Carbonell sips a drink of water in a hotel in Barcelona, the city to which he has traveled to present the book, he says that Homo antecessor practiced cannibalism. “After eating someone like them, they ate the fruit of the hackberry tree, the hackberry, to degrease the body,” notes one of the most prominent members of the Caimán Brigade. Apparently, the specialist and several of his colleagues coined this name in 1978, when a summer storm threatened the integrity of a site and the excavators lay down on the ground to divert the flood of water, so they ended up as full of mud as swamp alligators.
Some of the first settlers of Atapuerca were killed, chopped up and consumed just like wild boars, fallow deer and bison. A couple of investigations that have delved into the possible reasons conclude that the cannibalism of Homo antecessor was intended to protect its territory from intruders eager to benefit from its resources.
Research, for example, indicates that cannibalism for territorial reasons is common in chimpanzees and primates. Another study indicates that killing a hominid had a good cost-benefit ratio for Homo ancestors in terms of the relatively little effort involved in killing someone, when the attackers were much superior in number, and the amount of meat obtained.
Now, Bermúdez intervenes, today it is still impossible to determine whether the men, women and children who were part of the diet of Homo antecessor in Atapuerca were swallowed by members of their same species (“which would be cannibalism”) or by a different one (“in which case we would talk about predation”).
How many Homo antecessors could have lived in the mountains of Burgos and the Iberian Peninsula? Hundreds? Maybe thousands? “It's an interesting question,” Carbonell responds. “Possibly several tens of thousands, based on the large amount of industrial remains that we have found. If there had been few, there wouldn't have been so many fossils,” he replies.
Until the stellar appearance of Homo antecessor in 1994 in the part of the Atapuerca complex known as the Gran Dolina, Homo habilis had been the last species of the genus Homo to be discovered. It happened in 1964. However, shortly after the discovery of the two teeth at level TD6, Bermúdez and Carbonell already suspected that they could belong to the common ancestor of Homo sapiens (modern humans who emerged more than 200,000 years ago) and Neanderthals ( which appeared in Europe about 400,000 years ago and became extinct in their last stronghold of Gibraltar about 35,000 years ago).
The 1997 description of Homo antecessor in the magazine Science, in an article titled “A hominid from the Lower Pleistocene of Atapuerca, Spain: possible Ancestor to Neanderthals and Modern Humans”, had to face the reluctance of many experts, who considered that the colonization of Europe had been much more recent (and not older than 600,000 years). But, finally, after an article was published in the journal Nature in 2020, the dissidents had to give in in view of the robustness of the evidence.
The place where Homo antecessor decided to settle a little less than a million years ago, the Bureba Corridor, is a natural passage between the Cantabrian and Iberian mountain ranges that since time immemorial has been the scene of all types of migrations of animal species and populations of hominids, both from Europe to the Iberian Peninsula and from its interior to the Mediterranean.
According to Carbonell, the abundance of resources led the inhabitants of Atapuerca to not have to travel long distances, "but dozens or hundreds of kilometers, always following circuits (valleys, plateaus, rivers...)."
Regarding the prevailing climate, during the last million years there was an alternation of very cold and very warm periods. In the coldest cycles, ice covered much of Europe, up to northern France, 365 days a year. Only the Mediterranean coasts were spared, suggesting that several thousand individuals could have taken refuge there.
The vegetation found in the excavations of the Atapuerca site (case of the wild olive tree) and the presence of certain animal species indicate that about 850,000 years ago the climate of the Burgos mountains was temperate during the summer, with temperatures between 16 and 18 degrees.
Although the fossil remains are very fragmented, a good part of the human anatomy is represented, which has made it possible to fully reconstruct the morphology of the first settlers of Atapuerca. The facial features of Homo antecessor are, for example, very modern. “If we dressed the girl who appeared in the Gran Dolina [in the image that opens this article] like today, in a subway car we would not distinguish her from a woman today,” says Bermúdez.
Homo antecessor measured around 1.75 m, had a rib cage somewhat wider than ours, as well as very bushy and united eyebrows. Their skin was very dark, similar to that of the Australian aborigines. Furthermore, they were perfectly bipedal. However, the flakes they made with the quartzite from the terraces of the Arlanzón River resembled the rudimentary stone tools found in Africa between two and three million years ago. That is, they were very archaic.
Regarding the possible size of the clans, Carbonell dares to speculate that they were formed “by more than six members and less than twelve”, in the image and likeness of the Neanderthal camp of the Abric Romaní of Capellades (Barcelona). Of course, in certain periods, the bison hunters of Atapuerca reached eighty or one hundred individuals to be able to communally hunt herds of thousands of specimens, he adds.
The life cycle of Homo antecessor was very short. It is estimated that their life expectancy was, at best, in their early twenties, so everything was going very quickly: the struggle to survive childbirth, raising children, and the possibility of an early death.
“But they did not live in caves, but outdoors, next to fountains and rivers,” Carbonell tells us. “Caves are, in general, a very bad place to live, because they are humid, dark and can be occupied by animals,” confirms Bermúdez. The bear bones of the Ursus deningeri species found in the chasms of some caves in the Atapuerca mountain range, where the plantigrades were preparing to hibernate, attest to this.
If we try to project the appearance of the Atapuerca mountain range 850,000 years ago, it is possible to imagine, Carbonell glimpses, a vegetation similar to that of today (oaks, holm oaks, oaks and a coppice of rosemary, lavender and thyme), as well as the presence of animals such as bison, elephants, foxes, panthers and deer.
However, it still remains to be elucidated from where Homo antecessor could have reached the westernmost tip of Europe around 300,000 years earlier than previously assumed. One of Bermúdez and Carbonell's hypotheses is that our ancestor could have arrived from southwest Asia through the so-called Levantine Corridor, when hominids were preparing to colonize the Asian continent for the first time.
The Levantine Corridor (located very close to present-day Jordan) then enjoyed a climate acceptable for the life of some species, both in glacial and interglacial times. This natural corridor, located between the Mediterranean Sea and several currently desert regions, connects Africa with Eurasia. Apparently, over long periods of time, Southwest Asia greened and transformed into a region very favorable for biodiversity.
In this umbilical cord the “mother” population could have emerged that gave rise to the species that populated Africa and Eurasia from the end of the Early Pleistocene to the present. The fact that Homo antecessor combines a more than notable proportion of traits found in Homo sapiens and Homo neanderthalensis makes it clear that the humans of the Gran Dolina were direct descendants of that unknown species, which also gave rise to the Neanderthals. , the Denisovans and modern humans.
All of them “are blood brothers, born by a common mother who could have lived in the Middle East. You just have to be patient and wait for more finds to occur in the appropriate places. Let's trust in it”, can be read in the epilogue of the book signed by Bermúdez and Carbonell.
