Although today we are the only human species that inhabits the face of the Earth, this has not always been the case. In fact, our current ‘loneliness’ is exceptional, and as we trace further and further through evolutionary history we realize that, until very recently, we shared the world with other hominin species. After the recent description of Homo luzonensis , the panorama of what was happening on the planet a few thousand years ago is becoming more and more interesting, and it makes us realize that, surely, there are many different types of humanities, and that in the In the past, when groups of hominids moved and mixed less than today, various situations of isolation led species to very different evolutionary paths , each finding its own adaptive strategy to survive and reproduce in a different environment.
One of those evolutionary cousins that fascinates us the most is undoubtedly Neanderthal man. Although he has been stigmatized for many years as a gross and clumsy relative, apelike looking, loser in the battle for survival, the current view is – thankfully – changing, and we are finally beginning to recognize Homo neanderthalensis for who he really was: a a species very similar to ours, with which we share a very close common ancestor in time and of whom, in fact, we retain a certain genetic trace.
“I think that this fascination we feel for Neanderthals is mainly due to the fact that they lived with us”, reflects Ana Belén Marín Arroyo, a researcher at the International Institute for Prehistoric Research of Cantabria (University of Cantabria). ” Neanderthals had lived successfully throughout Eurasia for more than 200,000 years, but suddenly we arrived and in 5,000 years we will wipe them off the map … that, I think, is what generates the desire to know more.”
Marín Arroyo’s team has just launched a new project called SUBSILIENCE and funded by the European Research Council ( ERC Consolidator Grant ) that aims, precisely, to delve into the causes that led Neanderthals to their extinction. The idea is to study the impact of climatic and environmental oscillations in southern Europe at a key moment: the time when contact between the last Neanderthal populations and the first H. sapiens newly arrived from Africa occurred.
“The southern part of the European continent is strategic at the moment, because the Neanderthal populations had lived without any problem for more than 200,000 years, they had faced different climatic changes, but they were alone on the continent. Well, now we know that Denisovans were out there, and some other species, but there was no major problem with that ”, the researcher explains. “Surely there were moments of specific extinctions of some populations of Neanderthals, but they were not total. But a new species appears, H. sapiens , and the Neanderthal populations, which seem to have already been somewhat affected due to isolation and inbreeding, are retreating in southern Europe ”.
The importance of knowing local conditions
The point is that, although we have records that characterize the climate that existed on the European continent at that time, these data come from Greenland. ” These numbers do not have to reflect exactly what was happening in the Cantabrian Sea, in the south of the Iberian Peninsula or in Serbia “, indicates Marín Arroyo. With her new project, the researcher hopes to shed some light on these questions. His team has selected several sites in Croatia, Spain, Italy and Serbia, and will apply different analyzes with a common methodology to find out in what specific conditions these latter populations lived.
“What we want is to study their subsistence, which is what allows you to survive as a species, in different ecological environments. Now we have very scattered information, but nothing has been done globally, with the same methodology ”. The results, perhaps, allow us to answer with greater precision the great question of why Neanderthals became extinct.
“We know that Neanderthal extinction does not occur overnight throughout the continent, but rather occurs in a staggered manner in these areas,” the scientist explains, “and that is why we need to study how they adapted to a continental, Mediterranean climate. or Atlantic, and how they exploited the resources. And not only explain why Neanderthals became extinct but also why sapiens survived. Because we came from Africa, whose conditions had nothing to do with what was in Europe ”.
Rummaging through the trash
In order to elucidate the reasons for their extinction, and also to know more about Neanderthals, it is necessary to find out how they lived and related. Javier Baena Preysler is Professor of Prehistory at the Autonomous University of Madrid and directs the Laboratory of Experimental Archeology at that entity. “We are very interested in knowing how the Neanderthals moved through the environment, and what was their operating structure in terms of the exploitation of the environment and social organization “, explains the researcher.
“If we took a photo of a Neanderthal community we would be surprised at how many things they have. They make complex tools, we know that they tan hides and have clothes for cold moments, they made beds. In a deposit in the Cantabrian Sea, we were able to verify that they even created beds of eneas and fibers. They form families and human groups that are much more complex than what the classic vision tells us, according to which Neanderthals were stupid and were half naked, ”he explains.
One of the activities of his laboratory consists of imitating the carving of tools to find out what the remains that are produced in this activity are like and compare them with what is found in the deposits. “We use wood, deer antlers… in short, the same materials that we have seen used in the past. It is as if someone were to rummage through our garbage can to deduce how we eat or what tastes we have ”, indicates Baena. “ We obtain a very interesting experimental reference to be able to find out, by means of comparison, what appears in the deposits. It is as if you find a mobile phone case but you cannot find your mobile phone ”.
The thoroughness and detail with which investigators must proceed gives us an idea of the detective work that archaeologists carry out. “We are talking about a very scientific discipline but one that plays with very high margins and thresholds of uncertainty “, reflects Baena. And it is that, indeed, guessing how an extinct species lived and behaved thousands of years ago is a complex task in which you have to be vigilant: any minute detail can give us clues to solve the mystery.
“In the end, human remains are not the most important thing in the field of archeology. We are very excited to find them, of course… we go crazy when that happens and we celebrate it in style, but really a site, with everything it contains, is more informative on a historical, economic and social scale ”, explains Baena. For example, the type of rocks gives us an idea of the mobility of the groups, since if it is a material that does not appear naturally in that region, it is indicating that someone has transported it there.
Animal remains, on the other hand, provide a lot of information about what the groups studied ate or about their hunting techniques. In the case of Neanderthals, we know that they were fundamentally carnivores, although in recent years studies have appeared indicating that many populations would supplement the diet with products of plant origin. An example is the analyzes carried out from the tartar remains of several Neanderthals from the El Sidrón cave (Asturias), or the studies of sediments with fecal matter from the El Salt site (Alicante). “It is something to be expected”, reflects Marín. “ It depends on where you live or in what climate moment you are, you eat one thing or another. If you live in the center of Europe in a very cold time, you will eat mammoths and reindeer, because there are few vegetables. On the other hand, in some places in the southern part of the Iberian Peninsula it has been seen that the populations ate mollusks and hunted birds … each one eats what they have ”.
Neanderthals were starving
In addition, we must take into account another aspect that is perhaps less talked about, and that is the possibility that these individuals were starving. “The Neanderthal is always spoken of as a great carnivore, but we must bear in mind that prehistoric populations must have been quite hungry, and the consumption of meat should not have been daily, but perhaps once or twice a week,” he explains. Elías Sánchez Cañadillas, researcher at the Department of Prehistory, Anthropology and Ancient History at the University of La Laguna and specialist in a technique that analyzes the proportion of stable isotopes in bone remains to study the paleodiet of prehistoric hominids. Generally, a high value of δ15N (unit that expresses the proportions of nitrogen isotopes found in the sample) indicates a high consumption of animal protein.
“However, a drastic increase in nitrogen may also be indicating that these individuals were going through a period of famine,” says the scientist. “When it enters a state of deficiency, the organism begins to metabolize its own resources to obtain energy, and that translates into very high values of nitrogen 15. So we don’t know to what extent we are talking about super carnivores or populations that they were starving and, as a consequence, consuming their own reserves ”.
The Cantabrian researcher also shares this thesis: “The Neanderthals of El Sidrón were not vegetarians, they were so hungry that they were eating themselves. These populations are dated to 50,000 BP (before present), and one of my goals is to know what happens at that time with the herds of herbivores that have been hunting successfully for so many years. Furthermore, this hypothesis fits very well with other signs that have been reflected in the teeth of these populations and that reveal a certain degree of nutritional stress ”.
So the same, but so different
As we can see, the history of the collapse of the Neanderthal population is a convoluted puzzle in which many variables act, and the methods to rebuild its pieces are the most diverse: search for archaeological evidence in the sites, analysis of remains of everything type, isotopes, climatic reconstruction … Gathering all the evidence, what seems clear is that a host of circumstances participated in the extinction of our relatives (nutritional stress, inbreeding …) that, together with the emergence of H. sapiens on the continent, precipitated its end. In many respects, Neanderthals were, on the one hand, very similar to us, but on the other, they were not able to survive when our species entered the scene. “It is clear that something is happening, perhaps it is because they are anatomically different, because they have another brain organization, perhaps a different form of communication,” says Marín.
“We know that Neanderthals were hunter-gatherers, very mobile and dependent on resources, that they were very well adapted for thousands of years to the harsh and changing conditions of the European continent, they are strong and brave, capable of carrying out explorations of the environment. very elaborate ”, reflects Baena. “What I am clear about, however, is that their intergroup communication and functioning networks are quite ineffective. That is, they are capable of discovering carving systems like those used by the men and women of the Upper Paleolithic, but they are geographically isolated. They discover one thing and the discovery remains at the regional level. It gives the feeling that there is no fluid communication between the groups, and of course there is no population feeling , there is no such thing as the ‘Neanderthal nation’. The fact that they hybridize with sapiens can be very symptomatic that they do not look different from other groups ”.
That lack of versatility, of ability to adapt to sudden changes, was perhaps the sentence for Neanderthal man. “They are very stubborn, very stubborn in the way they exploit the environment, surely that is one of the causes of their extinction. They are born doing the same and they die doing the same. In some fields we have seen small innovations, but they don’t come out there, when they make changes they don’t communicate them to other groups ”, explains Baena. “On the other hand, at an anatomical level, it’s as if you compare a hundred meter sprint runner with a marathon runner. The Neanderthal is prepared to put in a very intense effort in a short time. Faced with climatic changes, variations at the fauna level, geological processes … their capacity for adaptation is not comparable to that of sapiens . The Neanderthals lived in a space in which changes are taking place and, to top it all, a very fast character appears on the scene, moving around everywhere and capable of rapidly occupying the ecosystems occupied by the Neanderthals and entering direct competition for the same resources ”. Several studies have in fact confirmed that the arrival of H. sapiens produces radical changes in the mobility circuits of Neanderthals in the final stages of the species. “It gives the feeling that someone has changed the balance, has broken in and has changed everything,” says Baena.
We still have a lot to know to fully reconstruct the story, and we will probably never have a complete vision, as each discovery that is produced also opens up new questions to solve. As mentioned at the beginning, today we are ‘alone’ on the planet, but until a very few years ago the picture was different. The common history of H. sapiens and H. neanderthalensis is a history of encounters, since we know that both species hybridized, at least in some moments, and also of disagreements, since they entered into competition for the same resources. Most likely, neither one nor the other knew when they made love and when the war, nor the Neanderthals were aware of their own disappearance, in fact a current of authors even questions their own definition as a species. The results of the new investigations will give us light to know new details in this fascinating film that is that of human evolution.
