HOLOCENE: CHARACTERISTICS, SUBDIVISIONS, FLORA, FAUNA AND CLIMATE - GEOGRAFÍA - 2025

The Holocene is the last epoch of those that make up the Cenozoic era and in which the planet is currently located. It began in approximately 10,000 BC and continues to the present day.

This period covers most of the development of humanity, even since Homo Sapiens had nomadic customs and had not yet discovered the usefulness of metals in making utensils.

Examples of animals from the Holocene. Source: Joseph Wolf

In this period, in which the planet changed very little, if biodiversity has been greatly affected, since many species of plants and animals have become extinct due to human action. Man has become the dominant species on the planet, at the cost of causing great harm to it.

General characteristics

Duration

The Holocene period extends from approximately 10,000 BC to the present day.

Human development

This period encompasses the entire development of humanity. It includes all the milestones such as the establishment of the first social groups and civilizations, writing, voyages of exploration, and great cultural and intellectual advances, among others.

Mass extinction of species

In the Holocene a continuous and permanent process of extinction of animal and plant species has been observed, caused by the action of human beings. This has been classified by specialists as the most serious extinction process, since the cause is not environmental factors, but one of the species that inhabits the planet.

Interglacial epoch

The specialists consider the Holocene as an interglacial epoch, since it began at the end of a period of intense cooling and it is expected that in the not too distant future another glaciation will take place, according to the projections made.

geology

This time has been of little importance from the geological point of view, since there have been no great orogenic movements or a major change in the configuration of the continents.

During the Holocene epoch, the different fragments that once belonged to Pangea have continued to move, but they have done so more slowly than in ancient times.

Speaking in figures, the distance that the different continents have traveled from the beginning of this time to the present has been 1 kilometer. Quite little, actually.

However, it is important to note that the continental masses will never stop moving and it is to be expected that within a few million years, they will collide again.

Changes in sea level

At the beginning of this time, many of the lands that are currently submerged under water were forming bridges between some regions.

An example of this is in the area of ​​the Bering Strait, between Alaska and Russia. Today it is occupied by a water channel that connects the Pacific Ocean and the Arctic Ocean, but during this time it formed a bridge between both continents.

Another very representative example is New Guinea and Australia, which were connected through a land bridge, which is now submerged under the waters of the Pacific Ocean in a place known as the Torres Strait.

What has changed significantly since the Holocene began has been sea level. During this time there has been a significant increase in its level, the main cause being the melting of the polar cap and some glaciers.

In this sense, the thaw was not a gradual process, but there were periods in which the thaw reached certain peaks, causing the sea level to rise abruptly.

Taking this into account, it is concluded that the sea level has risen a total of 35 meters since this time began. For approximately 3,500 years this rate has slowed down. However, in the last 25 years it has increased again to approximately 3mm per year.

This recent increase is due to what is known as the greenhouse effect, which has caused the planet's temperature to increase due to the action of some gases.

Weather

The temperatures during the Holocene are considerably milder than those of earlier times. Many specialists in the area agree that it is an interglacial epoch, since it began at the end of a significant cooling event. They do not rule out the possibility that another ice age will break out in a few million years.

During this time, a climatic event known as the "Holocene climatic optimum" occurred.

Holocene climate optimum

This is a period in which the planet's temperatures were quite warm. The average increase in temperature was between approximately 4 ° C and 9 ° C. According to specialists, this period of time had its beginnings in 6000 BC and lasted until 2500 BC.

During this process, the global warming was not uniform, since while some regions experienced an increase in their average temperatures, others experienced a decrease in them. The lands that suffered a cooling were those that were located further south.

Also, in certain regions that had always been desert, precipitation began to increase. A very representative example of this is the western part of the African continent.

Post cooling

Once the Holocene climatic optimum was completed, environmental temperatures began to gradually decrease, although there have been periods in which there seemed to be a recovery in temperatures, as occurred during the Middle Ages.

Little Ice Age

It was a period that lasted from the 14th century to the 19th century. It consisted of a time when environmental temperatures dropped significantly, mainly affecting the northern hemisphere of the planet.

Its causes have not yet been fully clarified, however, the ones that have gained greater strength are two:

In the first place, there is talk of a decrease in solar activity, as well as an increase in volcanic activity at the equatorial level. The latter resulted in an emission of gases that caused a darkening of the atmosphere with ashes, making it impossible for the sun's rays to pass through.

Finally, at the end of the 19th century, this little ice age began to subside. Many believe that it is due to the Industrial Revolution, thanks to which a large number of industries were established that began to emit gases into the atmosphere. These gases could intervene in the gradual increase in temperatures, which has been maintained until today.

Flora

The development of life during the Holocene epoch has not undergone many changes from an evolutionary point of view. One of the aspects that has attracted the most attention from specialists is the marked tendency to disappear of animal and plant species.

Many coincide in relating this species of continued extinction with the appearance of the human being. There is talk of continued extinction because it has been maintained until even the present time, in which there are a large number of endangered species.

The Holocene epoch extends to the present day, so the plants that have existed during this time are quite well known.

The most widely distributed plants on the planet are angiosperms, better known as plants with protected seed. Likewise, in the tropical regions, close to the equator, the prevalence of humid forests, with abundant plants and great biodiversity, is appreciated. The most important forest on the planet is the Amazon, since it provides a large amount of oxygen that is breathed throughout the planet.

Also, in the areas near the poles, vegetation changes. The lush and humid plants of the jungle are left behind to make way for other types of trees. like pine forests, adapted to low temperatures. At the poles, the closest thing to plants are small lichens.

Likewise, there are plants that have specialized to withstand environments with high temperatures and little water availability, which are located in desert regions such as the Sahara in Africa, the Atacama in Chile or the Gobi in Mongolia.

It is important to point out that due to human activity, forests and jungles have been affected, mainly by industrialization and the expansion of communities, which has been taking land away from green areas, so important for the maintenance of life in the planet.

Fauna

The animals have not varied much during the Holocene either. Those that have managed to maintain themselves over time have not undergone any change or evolution.

What has been accentuated and prolonged in time is the extinction of animal species, both terrestrial and maritime. Of course, this has happened by the action of human beings, who in their quest to conquer the planet has endangered both plants and animals.

Among the animals that existed in the early Holocene and that unfortunately became extinct, we can mention:

Mammoths

They were animals very similar to today's elephants, belonging to the same family: Elephantidae.

They were characterized by having a large trunk whose sides protruded huge fangs. Their body was covered with hairs, which allowed them to survive the low temperatures.

Skeleton of a mammoth. Source: Ghedoghedo

Its size was variable, since fossils that are much larger than current elephants have been collected, but records of other species called dwarfs have also been found.

Dodo

Dodo

It was an endemic bird to Mauritius. It was small in size, weighing approximately 12 kg and one meter high. They had no ability to fly and their bodies were somewhat squat.

Specialists often speak of the dodo as an emblematic example of the extinction of a species by human action. This bird lived quietly in its habitat until the moment when man arrived on the island at some point in the 16th century. It became extinct after about a hundred years after the arrival of human beings to its habitat.

Moa

It was a bird that inhabited New Zealand until the 15th century, when it became extinct. According to its appearance it was very similar to the ostrich. It was large; They could measure up to three and a half meters and reach an approximate weight of 275 kg.

The extinction of these birds occurred due to the invasion of Maori hunters to their habitat.

Animals in danger of extinction today

The International Union for the Conservation of Nature is in charge of listing animals that are in danger of extinction, as well as monitoring the status of species that are already on the list.

Among the species that are in imminent danger of extinction can be mentioned:

• Orangutan
• Iberian lynx
• Wild camel
• Asiatic antelope
• Slender-billed vulture
• Tiger-tailed seahorse
• Black browed albatross
• Blue duck

In the Holocene, so many species have become extinct that this process of gradual extinction has even been considered as the sixth great extinction. Most alarmingly, a large number of species have become extinct in a relatively short period of time.

Subdivisions

The Holocene epoch is not divided taking into account the fossils recorded and found, as it has been done with the previous epochs. The divisions of this age are based on the evolution and development of humanity. However, there are several proposals from specialists. Among the most accepted is the following:

-Stone age

Although when the Holocene began, the Stone Age already existed, it counts as one of the divisions of this period. It culminated when humans began to use metal tools and utensils. Likewise, the Stone Age, in the Holocene, includes two periods:

Mesolithic

It is considered a period of transition between the Paleolithic and the Neolithic. It extended from 10,000 BC to 6,000 BC. During the Mesolithic period, man changed his nomadic customs and the first sedentary peoples began to appear.

Neolithic

It began in 6,000 BC and ended around 3,000 BC During this period, human beings began to practice certain activities such as agriculture and livestock, which helped to reaffirm their sedentary habits.

-Age of metals

It is after the Stone Age. Its beginning was marked by the origins of metallurgy. Here man discovered that by subjecting metals to heating, they melted and could be molded into tools and utensils.

Likewise, various aspects of human life, such as agriculture and construction, underwent a great evolution. During this age, commerce and navigation also emerged. The Metal Age comprises three well-defined periods, dependent on the predominant metal worked by humans: copper, bronze, and iron.

Copper age

It began approximately in 6550 BC. Here man began to work, apart from copper, silver and gold. He used them to create utensils such as tools for working the land and weapons. In the same way, these metals were worked by man to make ornamental and decorative elements.

Bronze Age

It had its beginning in approximately 2800 BC Upon discovering the fusion between tin and copper, man began to use this alloy to develop utensils and tools. In addition, for the first time societies begin to be divided by hierarchies.

Iron age

At this age, man learned to extract iron from the subsoil and used it in the construction of weapons. It began in 1,000 BC and came to an end the moment writing was invented.

These preceding ages correspond to the historical period known as Prehistory. Once writing was invented, the following ages of human history began to develop:

1. Ancient Age: it begins with the invention of writing. The date is not specified exactly. It culminated in the 5th century AD. During this period, various civilizations emerged in various parts of the world: Greek, Roman, Egyptian, Mesopotamian, and Chinese, as well as pre-Columbian civilizations. This age ends with the fall of the Roman Empire.
2. Middle Ages: it extended from the 5th century to the 15th century. It was a fairly long period of time, characterized by the rise of feudalism, the rise of agriculture and livestock, the crusades and theocentrism.
3. Modern Age: it begins in the XV century, taking as a reference the discovery of America and ends in the XVIII century with the French Revolution. During this period there are European exploration trips and the establishment of colonies in America and Africa. Likewise, in Europe there was the Renaissance, a period in which there was a boom in the arts and the emergence of great artists such as da Vinci and Michelangelo.
4. Contemporary Age: it began in the 18th century and continues to the present day. It has been a period of many changes, including several revolutions (French, Cuban, Russian), several major wars (First and Second World War, Vietnam War), extensive intellectual development (Einstein, Freud…) and a great technological development, the most important being the internet.

References

1. Fairbridge, R., Agenbroad, L. Holocene Epoch. Retrieved from: Britannica.com
2. Mackay, AW; Battarbee, RW; Birks, HJB; et al., eds. (2003). Global change in the Holocene. London
3. Roberts, Neil (2014). The Holocene: an environmental history (3rd ed.). Malden, MA: Wiley-Blackwell
4. The Olocene Epoch. Obtained from: ucmp. Berkeley.edu
5. Zimmermann, Kim Ann. Cenozoic Era: Facts About Climate, Animals & Plants. Retrieved from livescience.com