Holocene: what it is, duration and characteristics of this epoch

Let's see what the Holocene is and what are the characteristics of this geological epoch.

Geological time scales allow us to place our existence at a specific point in time and, in addition, to know what life was like for our ancestors and the first living beings that inhabited the Earth.

Although we humans have transformed this planet to our liking and needs, the reality is that the Earth is inconceivably ancient, as its origin is placed 4,543 billion years ago. We are not even capable, as a species, of imagining such a vast time scale.

Life arose some 3.5 billion years ago, provoking diverse radiations through processes of speciation and evolution, which has led to the almost 1.5 million animal species described today (although it is estimated that there are more than 7 million). The genus Homo (to which we belong) appeared approximately 2.5 million years ago, changing the destiny of our planet irrevocably.changing the destiny of our planet in an irremediable way.

When we talk about geological epochs and periods, we usually go back to the Cambrian and its explosion of aquatic species with alien crustacean forms, or to the Jurassic and the dominance of dinosaurs and beings of unthinkable sizes. What is seldom explored, due to its proximity to the present day, is the Holocene, a period in which the the Holocene, the epoch in which you and I find ourselves.Do you know what surrounds us temporally and what lies ahead for us as a species? Here we tell you.

What is the Holocene?

The Holocene is a division of geological time scale, the last (and current) epoch of the Quaternary period.. The Holocene is an epoch encompassed in the Quaternary period, which in turn is part of the Cenozoic Era. To understand all these terms a little better, we will illustrate this division with a small diagram.

Cenozoic EraCenozoic Era: it began about 66 million years ago and continues to the present day. It is the third (and last) era of the Phanerozoic eon.

• Paleogene Period: it began about 66 million years ago and ended 23 million years ago.
• Neogene Period: spanned 23 million years and ended 5.33 million years ago.
• Quaternary Period: began 2.59 million years ago and extends to the present. It includes the Pleistocene (began 2.59 million years ago and ended approximately 10,000 B.C.; the famous glacial period occurred here); and the Holocene (began 11,700 years ago and extends to the present and is considered the absolute reign of the human species).

Perhaps this short list has made it clearer, hasn't it? The only human species that has lived throughout the entire Holocene is the Homo sapiens and, during it, we have developed as a society language, agriculture and, in short, the civilization on which all the foundations of our survival are based. Unfortunately, all these advances have not come without the consequent ecosystemic detriments, as we will see in later lines.

Characteristics of the Holocene

Approximately 11,700 years have passed since the beginning of this epoch until the writing of these lines, so it is a bit complex to summarize everything that has happened during this time interval without covering several volumes of an encyclopedia. Even so, we will make the effort to give you a general outline of it.

On a geological scale and taking into account the age of the Earth, about 12,000 years is quite short. Therefore, it is considered that the tectonic movements (continental drift) that have determined the study of other stages here are almost negligible: less than 1 kilometer, an irrelevant figure. However, it is necessary to take into account that the Holocene began after the last glaciation, a type of climatic phenomenon that dominated during the Pleistocene..

Since all that ice had to go somewhere with rising temperatures, at the beginning of this epoch the sea level rose by about 35 meters in height and 120 meters since the last glacial maximum, about 20,000 years ago. This change was not gradual, but occurred in the form of "pulses". It is interesting to know that, in addition, we are in an interglacial period, so it is not at all ruled out that in the future the Earth will again suffer a massive glaciation (as has happened on other occasions).

Evolution is not a mechanism that generally works at a dizzyingly fast pace, so we can say little about changes in flora and fauna. Although many species have become extinct during these more than 10,000 years, at the ecosystemic level what has been most marked have been the changes in the distribution of taxa in different areas of the Earth, largely due to human action. In any case, it is known that the large mammals prepared for life in the snow (mammoths and saber-toothed tigers, among others) disappeared between the end of the Pleistocene and the beginning of the Holocene..

Since we have no reliable fossil faunas to rely on (since there is no marked difference in living things compared to today), the Holocene is measured on the basis of the different stages of human development. The beginning of this period corresponds to the European Mesolithic epoch, where the last societies of hunter-gatherer humans, primarily nomadic in nature, took place. From this point on, history writes itself.

Holocene or Anthropocene?

To continue making an unbiased historical tour through the Holocene without touching on certain topics, however thorny they may be, would be to miss the truth. We must admit it: the expansion and development of the human being has been exchanged for the well-being of planet Earth in exchange for progress. For this reason, part of the scientific community proposed at the beginning of the 21st century the term "Anthropocene" to replace the era in which the to replace the epoch in which we supposedly find ourselves, the Holocene.

Most ecologists, zoologists, conservationists (and scientists in general) agree on one thing: we are on the brink of a mass extinction that is advancing at a frightening rate. The current extinction rate is approximately 100 to 1,000 times higher than expected for the Earth at the evolutionary level. Even the worst episodes do not match the present, as living things are now disappearing on a scale (at least) 10 times greater than any past catastrophic period you can think of.

To standardize the changes that the Earth is suffering is something complex, and for that reason, we try to circumscribe the current "Anthropocene" in a clear and quantifiable base of ideas at a physical-chemical level.. Among the possible patterns considered are the following:

• Increase in atmospheric CO2, which is too gradual.
• Variations in the percentages of stable isotopes (non-radioactive nuclides) of carbon due to anthropic activity.
• Presence of radioactive isotopes due to atmospheric nuclear explosions, due to well-known war episodes.
• Increase in the level of sulfates recorded in the ice sheets of both hemispheres, due to the eruption of the Tambora volcano in April 1815.

These are some of the "markers" that could be used to define the Anthropocene at the geological level, but, undoubtedly, what determines it is the extinction of the Earth, what determines it is the massive extinction of living beings and the degradation of ecosystems.. The more the human species expands, the less space is available for nature.

Without going any further, it is estimated that an average of 150-200 species of living beings disappear every 24 hours. No more and no less than a single day. Of all the species monitored by the International Union for Conservation of Nature (IUCN), 28% of them are threatened, some 35,500. We could go on giving devastating data, but we believe that the idea is more than clear: the Holocene or Anthropocene is characterized by human progress, but at the same time implies the death and destruction of the planet as we know it.

Summary

After the data presented here, it is difficult to end on a positive note. The Holocene is characterized by human progress, with all the negative and positive aspects that this entails.. During this period we have created language, and thanks to it, we have learned to name love, affection, affection and empathy. We have also traveled to the moon and discovered many secrets of the world around us, for without the human species, the term "knowledge" would probably not even have taken shape.

In short, our species is capable of the most beautiful things and the worst crimes at the same time, and the events collected throughout the Holocene exemplify this perfectly. Only time will tell where civilization and the Earth itself are headed, but, unfortunately, the current data are not at all encouraging.

Bibliographical references:

• Arias-Maldonado, M. J. (2020). Anthropocene.
• Carpenter Slavens, J., & Sánchez, G. (2013). Middle Holocene/Late Holocene environmental changes in the Sonoran Desert and their implications for Yuto-Aztecano diversification and maize diffusion. Andean Dialogue, (41), 199-210.
• Zamora, M. E., Huerta, A. H., Maqueo, O. P., Badillo, G. B., & Bernal, S. I. (2016). Global change: the Anthropocene. SCIENCE ergo-sum, Multidisciplinary Scientific Journal of Foresight, 23(1), 67-75.