Homo erectus: what was it like and what distinguished it from us?

Human beings are an intellectual slave to the great questions that have been asked for as long as they can remember: where do we come from? Where are we going? The search for him is, deep down, what motivates all the science that makes the planet on which we live go round.

Perhaps one of the basic answers to such questions is hidden in the earth we walk on, compacted under the sediments of time, she avoids the naked gaze of those who wander over her without questioning who he is or why he is alive and breathe.

Fossils, stony bones that silently bear witness to what we once were, shout at us about nature itself that we harbor in our genetic code. For this article, we will travel many thousands of years back in time to meet someone closer than we think: to erectus.

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discovering the erectus

He erectus ("standing man") belongs to the genus Homo, which describes a subgroup of bipedal primates with a skeleton and nervous system designed for walking in an upright posture, and among which is the current human being (

Homo sapiens). As for homo erectus, it is known that it lived until about 70,000 years ago, although its origin dates back a long time (about two million years).

The first fossil remains of him were found on the island of Java (Indonesia), and for this reason he was dubbed the "Java man". At that time it was determined that it must be a species of primate without any connection to the current human being, since the perimeter of his cranial vault did not allow inferring that the development of his cognitive abilities was even remotely close to the our. It was therefore labeled under the scientific nomenclature of Anthropopitecus erectus, although as more details about him were discovered, his name was modified until he received the one by which he is known in the present.

With the passage of time it has been discovered that the fossil remains of the erectus They can be found in many geographical regions of Asia and Africa, so it follows that He was the first being capable of moving far beyond the place where all his ancestors took root (East Africa). This evidence, together with others that will be detailed throughout the article, were the first to suggest that perhaps not it was just another ape: but it could be one of the hominids closest to what we are today, an adventurer of the prehistory.

What was his appearance?

It is important to note, first of all, that the erectus It was a species that showed great anthropometric variability, reaching the point of confusing the community science for decades (considering that the remains found could really belong to two or more animals different). All of this also extends to the discrepancies between males and females (sexual dimorphism), as they were more pronounced than in the current human. For this reason, in this article we will talk about the average traits in the individuals of the species.

Today we know that the arrangement of its vertebral column and its skull allowed it to move bipedally, being endowed with feet whose bone organization is suggestive of the ability to walk upright (hence precisely the name with which it was baptized) and even to run long distances and hunt while maintaining the same position. It lived on the ground, and not on the trees, at least from what can be deduced from its bones.

The remains found in Africa are undoubtedly much smaller than those found in East Asia; in fact, they even received a different name in their day (homo ergaster) which is still in use today. This implies, of course, that their skulls were also very different. This enormous variability is undoubtedly one of the distinctive features of the erectus and what greater uncertainty has generated to those who dedicated their lives to understand it as a unified species.

Determining the size of the brain is essential for the knowledge of the intelligence of all living beings, since the proportion that is determined for its relative weight (with respect to that of the body), it is the most used and reliable index to make an estimate of the regard. In the specific case of this species of human, skulls with a volume between 700 and 1100 ml have been identified, which places them above the gorilla (600 ml) and close to the human (1200-1500 ml). The average that is estimated today is 940 ml, inserted in a very low cranial vault that gave it a remarkable capacity for development.

He erectus He was also a large and corpulent being, having been agreed that his height could reach 1.80 meters, despite the fact that It would depend on the conditions in which they lived (resources, weather, etc.) and the presence or absence of a predator natural. They had a strong jaw and no chin, with teeth smaller than those of other hominids. with those who came to live in the African territory (such as the Homo habilis or the Homo rudolfensis).

Both brain and physical size have long been used to explain how they came to be dispersed across this planet, for they necessarily had to enter inhospitable terrain to reach East Asia from the African continent, which required strength and intelligence. It has been estimated that their ability to adapt to the environment was very similar to that of the current human being, despite the fact that in this sense there are still many unknowns that remain without an answer.

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What were their habits?

He erectus It was, without a doubt, an animal with a tendency to gregariousness. He lived inserted in small groups of around 30 individuals, and had a series of differentiated roles that gave the community a clear sense of hierarchy. Their social organization was much more rudimentary than that of the current human being, which required the experience of a cognitive revolution. to be able to bear coexistence in big cities, but it is a valuable sample of how communality was lived in times primitives.

A very interesting fact about this hominid is that it probably he knew fire well, and even used it as a tool to prepare a diet based on meats (as inferred from the bone hypervitaminosis that is usually obtained in the mineral analysis of his femurs), something that contributed to his enormous brain and technological development. And it is that they could also use weapons (lithic) and various instruments, for which there is a growing sophistication, and that allowed a survival that extended far beyond that of homos contemporaries.

As it could not be otherwise, they gained access to meat through hunting, for which they organized incursions in which there was evidence of great ability to collaborate in the achievement of a purpose shared. It is also believed that they could steal from those who competed with them for vital resources, or in case of need, join forces with nearby tribes to prey on a larger animal (after which they tended to disperse from new). They also acted as scavengers, feeding on the remains of carcasses that other animals left behind.

Although there is much doubt that this homo was capable of producing an articulated language with which to share "symbols" of a verbal nature, it is known that they used trade (without currency) with related tribes, exchanging the resources necessary for their survival. It is also very likely that the females of each of the groups were involved in this process, which They became trade products in order to increase the reproductive capacity and reduce the damage to the inbreeding.

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Why was it extinct?

The reasons why a species becomes extinct are always diverse, complex and even controversial. In the case at hand, it is clear that they had to go through a particularly difficult climatic period, in which The resources available to them to satisfy the most basic need of their bodies began to become scarce: the feeding. And perhaps all this could have happened after the great volcanic eruption of Toba.

This event occurred in the same period for which the end of the erectus (about 70,000 years ago), north of Sumatra (an island in Indonesia), and It meant a severe volcanic winter that reduced the population of primates and hominids. This moment is considered, in numerous scientific publications, as the most relevant milestone to explain the extinction of many of the species that inhabited the earth at that time, since it meant dramatic changes in the flora and fauna that they needed for their subsistence.

This incident caused the population of homo erectus (and other species) to be greatly decimated, losing around 90% of the total number of individuals and breeding pairs. Today it is known that the areas close to the marine coasts suffered to a lesser extent the ravages of the volcanic winter (a dense layer of dust that prevented the growth of vegetation at a global level for about five or six years), since there are sites very close to those of such an incident that they were affected, but in which homo erectus was able to continue his life with absolute normality (thanks to the abundance of fish).

There are also several recent studies that point to the hypothesis that, for reasons still unknown, Homo erectus could begin to neglect the processes through which he made his weapons and tools. This can be deduced from the fact that they used precarious materials for themselves, by deciding not to travel to relatively close places where they they could have provided themselves with a better raw material, settling for poor manufacturing that could reduce their efficiency in hunting and other activities.

These models, fundamentally theoretical and still uncorroborated, would suggest that "laziness" was a factor contributor to the extinction of a species that harbored the potential to survive the calamity that corresponded to live In any case, the day the Lake Toba volcano erupted, human beings faced what was undoubtedly the most tragic page in its long natural history.

Bibliographic references:

• Baab, K. (2015). Defining Homo erectus. 2189-2219. doi: 10.1007/978-3-642-39979-4_65.
• Carotenuto, F., Tsikaridze, N., Rook, L., Lordkipanidze, D., Longo, L., Condemi, S. and Raya, P. (2016). Venturing out safely: The biogeography of Homo erectus dispersal out of Africa. Journal of Human Evolution. 95. 1-12. doi: 10.1016/j.jhevol.2016.02.005.