Concept in Definition ABC

Geologists divide Earth's history into eras. At present we are within the Quaternary era and previously there was a Tertiary era, another Secondary and, logically, a Primary. Each era is in turn divided into periods. Within the Quaternary era there are two periods: the Holocene dates back 10,000 years and the Pleistocene, which began 2 million years ago.

As for the term Pleistocene, it is a neologism that literally means "the most recent".

It is worth remembering two facts that frame the geological ages: it is estimated that the Earth is 4.5 billion years old and that the first life forms appeared 3.5 billion years ago. In this scheme general the species human is only 200,000 years old.

What happened in the Pleistocene?

During this geological period the continents already presented the same appearance they currently have, since continental drift has not caused significant changes.

In the Pleistocene the ice spread over a quarter of the land surface (In our time ice occupies approximately 10%). Likewise, various glaciations occurred within warmer interglacial periods.

As the glaciations advanced, the animals moved towards the ice-free regions

The migrations produced triggered processes of natural selection (Many species did not adapt to climatic fluctuations and ended up becoming extinct, as happened with the mammoth or the saber tiger).

During colder periods, grasslands developed in regions closer to the poles, and coniferous forests and deciduous trees expanded during warmer periods.

In the end the first hominids appeared on the planet and for this reason there is talk of a new period, the Holocene (the current stage within the Quaternary period).

In the Pleistocene the ancestors of human beings managed to dominate fire

It was in the Tertiary era that the first primates appeared. Over time they evolved into two branches: prosimians and apes. Two million years ago a new species appeared, Homo erectus. His great contribution was the invention of fire, one of the great revolutions in history.

Homo erectus was weak in comparison with the great predators of your habitatBut he had a more developed brain. With a greater intelligence He was already able to control fire for different purposes: to warm himself, to cook and to protect himself from wild beasts.

Fotolia photos: popaukropa / dottedyeti