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

What were the characteristics of Homo erectus and how did it behave? Let's see.

Human beings are intellectual slaves to the great questions they have asked themselves for as long as they can remember: where do we come from? where are we going? His quest is, in the end, the one that motivates all the science that makes the planet we live on revolve.

Perhaps one of the basic answers to these questions is hidden in the earth we walk on, compacted under the sediments of time, elusive to the naked gaze of those who wander over it without questioning who they are or why they are alive and breathing.

Fossils, stony bones that silently bear witness to what we once were, shout at us about the very nature we harbor in our genetic code. For this article, we will take a journey many thousands of years back in time, in order to learn about someone closer than we think: Homo erectus Homo erectus.

Discovering Homo erectus

The Homo erectus ("standing man") belongs to the genus Homowhich describes a subgroup of bipedal primates with a skeleton and nervous system designed for upright ambulation, and among which the present-day human being (Homo sapiens). As for homo erectus, it is known that it lived until approximately 70,000 years ago, although its origin dates back a long time (about two million years).

Its first fossil remains were found on the island of Java (Indonesia). (Indonesia), and for this reason it was baptized as "Java man". At that time it was determined that it must be a primate species with no connection to the current human being, since the perimeter of its cranial vault did not allow inferring that the development of its cognitive abilities was even remotely close to ours. It was, therefore, labeled under the scientific nomenclature of anthropopitecus erectus, although as more details were discovered about it, its name was modified until it was given the name by which it is known today.

Over time, it has been discovered that the fossil remains of the Homo erectus can be found in numerous geographic regions of Asia and Africa, so it follows that Homo erectus was the first being to be able to move around. was the first being capable of moving far beyond the place where all its ancestors took root (East Africa).. This evidence, along with others that will be detailed throughout the article, were the first to suggest that perhaps it was not just another ape: it could be one of the closest hominids to what we are today, a prehistoric adventurer.

What was its appearance?

It is important to point out, first of all, that the Homo erectus was a species that showed great anthropometric variability, to the point of confusing the scientific community for decades (considering that the remains found could actually belong to two or more different animals). This also extends to the discrepancies between males and females (sexual dimorphism), as they were more pronounced than in modern humans.. For this reason, this article will discuss the average traits of the individuals of the species.

Today we know that the arrangement of its spine and skull allowed it to move bipedally, being endowed with feet whose bone organization is suggestive of the ability to wander upright (hence precisely the name with which it was baptized) and even to run long distances and hunt while maintaining the same posture. It lived on the ground, and not on 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 were even given a different name at the time (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 distinguishing features of the Homo erectus and which has generated the greatest uncertainty for those who dedicated their lives to understanding it as a unified species.

Determining the size of the brain is essential for the knowledge of the intelligence of any living being, since the proportion determined for its relative weight (with respect to that of the body), is the most used and reliable index to make an estimate in this regard. In the specific case of this species of human, skulls have been identified with a volume between 700 and 1100 ml.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 conferred a remarkable capacity for development.

The Homo erectus was also a large and corpulent being, and it has been agreed that its height could reach 1.80 meters, although this would depend on the conditions in which they lived (resources, climate, etc.) and on the presence or absence of a natural predator. They had a strong jaw and no chin at all, with smaller teeth than those of other hominids with which they coexisted in the African territory (such as the Homo habilis or Homo rudolfensis).

Both brain and physical size have long been used to explain how they came to disperse across this planet, as they necessarily had to venture into 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 today's human beings, although in this sense, they had to adapt to the environment.Although in this sense there are still many unknowns that remain unanswered.

What were their habits?

The Homo erectus was, without a doubt, an animal with a tendency towards gregariousness. They lived 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 today's human beings, who required the experience of a cognitive revolution to be able to coexist in large cities, but it is a valuable example of how communality was lived in primitive times.

A very interesting fact about this hominid is that it probably knew fire well, and even knew how to use it. knew fire well, and even used it as a tool to elaborate a meat-based diet (as inferred from the hyperbolic (as inferred from the bone hypervitaminosis usually obtained in the mineral analysis of their femurs), something that contributed to their enormous cerebral and technological development. They were also able to use weapons (lithic) and various tools, for which a growing sophistication is evident, and which allowed for a survival that extended far beyond that of contemporary homo.

As could not be otherwise, they obtained access to meat through hunting, for which they organized raids in which there was evidence of a great capacity to collaborate in the achievement of a shared purpose. It is also believed that they could prey on 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 again). They also acted as scavengers, feeding on the remains of carcasses left behind by other animals.

Although it is highly doubtful that this homo was capable of producing an articulate language with which to share "symbols" of a verbal nature, it is known that they did 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 became products of trade in order to increase the reproductive capacity and reduce the damage of inbreeding.

Why did it become extinct?

The reasons why a species becomes extinct are always diverse, complex and even controversial. In this case, it is evident that they had to go through a particularly difficult climatic period, in which the resources they had available to satisfy the most basic need of their bodies: food, became scarce. 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 Homo erectus (about 70,000 years ago), north of Sumatra (an island in Indonesia), and it was a severe volcanic a severe volcanic winter that depleted the primate and hominid population.. 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, because it meant dramatic changes in the flora and fauna they needed for their subsistence.

This incident caused the population of Homo erectus (and other species) to be greatly decimated, with about 90% of the total number of individuals and breeding pairs being lost. Today it is known that the areas near the sea coasts suffered less from the ravages of the volcanic winter (a dense layer of dust that prevented the growth of vegetation globally for about five or six years), as there are sites very close to those of such an incident that were affected, but in which homo erectus was able to continue its life with absolute normality (thanks to the abundance of fish).

There are also several recent studies that point to the hypothesis that, for reasons as yet unknown, Homo erectus may have begun to neglect the processes by which it made its weapons and tools.. This is deduced from the fact that they used precarious materials for them, deciding not to move to relatively nearby places where they could have obtained better raw materials, settling for poor manufacturing that could have reduced their efficiency in hunting and other activities.

These models, fundamentally theoretical and as yet uncorroborated, would suggest that "laziness" was a contributing factor to the extinction of a species that harbored the potential to survive the calamity that befell it. In any case, the day the Lake Toba volcano erupted, mankind faced what was undoubtedly the most tragic page in its long natural history.

Bibliographical 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 Raia, 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.