Very good question. And perhaps the most important one to understand where we come from, all the people around the world today. Since this explanation is part of what our schools have failed to tell us, I will answer your question, Przemek, in particular detail in this special article.
First, simply a quote from my latest book, "Me, You, and All of Us; Where do we come from, and how can we build a Familiar Democracy"; from pages 160-162.
"Let us now imagine the corresponding situation within the Cosmic Hierarchy in a little more detail. The Earth - together with the entire Solar System - wanders through Space (i.e. the space of the largest energetic quantum imaginable to us), in which our Cosmic Hierarchy has existed for billions of years. When a period of level n of this Hierarchy approaches its end, the Earth also comes close to the cosmic energy bridge that connects the centre of the member of level n with the centre of the higher level n+1. Such bridges hold the huge cosmic carousel together. A sketch of the cosmic energy bridges for the four lowest levels of the Solar System Cosmic Hierarchy is presented in the following figure. But each next level of the hierarchy also looks relatively similar to the sketch.
The energy bridge between levels 8 and 9 is the second most powerful in the whole hierarchy observed so far. It does not, of course, consist of individual atoms, molecules or similar "delicate" particles. It has to hold together not only whole galaxies, but also whole clusters of galaxies. So it itself consists of huge, massive chunks of cosmic matter, like comets and boulders, which fly through space in flocks of millions divided along such an energy bridge. In miniature, one can imagine such a bridge as the tail of a comet, with the difference that at the end of the comet's tail, no satellite of the comet's nucleus accompanies it.
The Earth (with the entire Solar System) thus approaches a bridge of the certain level. The number of collisions of the Earth with the bodies of the bridge gradually increases the closer the Earth gets to the "main road" of the bridge. In other words, the supply of cosmic energy to the Earth increases. From the point of view of the Earth's inhabitants, however, one would say that the number of cosmic impacts on the Earth increases. We see a schematic sketch of two quantum jumps of level n with a full period of this level between them on the diagram below."
So much for the book's general explanation of an energetic leap within our Cosmic Hierarchy of the Solar System.
Earlier in this book, however, in Chapter 8, I gave my answer to the question: "Where did We come from?" So what happened in the year -4720? Several, estimated dozens of such catastrophes as Chernobyl, Fukushima, Sumatra (tsunami), Pinatubo (volcano) and Chelyabinsk (meteorite) together, only a hundred times more energetic. And that was only the year of the theoretical peak of the last cosmic leap of stage 5, which has separated the previous period of this stage, the life period of the Neanderthal Genus (see the picture below),
from the life period of our own Genus Homo sapiens Sapiens (see below).
Exactly this peak is shown on the very chart you asked your question about:
And on the enlargement of his right side:
we can finally see our First Global Civilisation as the seventh evolutionary civilisation in the series of so-called Great Civilisations of "Modern Humanity". Of the Great Civilisations of the last three species of Neanderthals: Cro Magnon Humans, Regular Atlanteans, and Evolutionary Atlanteans, our history is silent to this day. That must change now. Also because of your question. So thank you in the name of our grandchildren and their children.