Earth and Moon

Origin and evolution of the Earth

Origin and evolution of the Earth

This chapter summarizes the geological and biological history of planet Earth in 10 pages, making a simple and educational journey through all the stages that go from its formation to the present.

When talking about the origin of the Earth, there is little to say about what happened during the first two thirds of the evolution of the Universe, only that, at some point, a spiral galaxy was formed that we call the Milky Way.

In one of the arms of that galaxy a star, our Sun, condensed some 4,540 million years ago. Around them, different bodies were formed, rotating, including our planet, the Earth.

The Earth was originally an incandescent mass. Slowly, that ball cooled down and acquired a form similar to what we know today. Although the changes in those early times had to be more abrupt and abundant, the Earth has not stopped evolving, and continues to do so.

The origin of life on Earth

Life arose when the appropriate conditions were met. First they were simple organic compounds; then unicellular organisms; later the multicellular, vegetable and animal appeared. If we compare the history of the Earth from its origin with one day, humans evolved from other mammals just a few seconds ago.

It is not known with certainty which was the origin of life. I may appear casually, by the Earth's own chemical reactions, or it could arrive from space, as suggested by the panspermia theory. In any case, about 4000 million years ago there were already molecules capable of replicating or cloning; In short, reproduce, the basis of life.

Both religions and sciences have divided the origin and evolution of the Earth and life into various phases. Some more poetic, such as creation in seven days of the Bible, others more rigorous, such as the geological ages that science accepts. In AstroMía we will focus on the latter.

This is the story of our house, the Earth, its origin and the changes that led it to be what it is. It is the story of the beings that inhabited it, how they arose, evolved and became extinct. And it is our story.

In this chapter:

How was the Earth formed ?: The Earth we know looks very different from what it had shortly after its birth, about 4 ... Read pageGeological history of the Earth: From its formation until today, the planet Earth has undergone many changes ... Read pageGeological history: the Precambrian: The Precambrian is a very long period in the evolution of the Earth that covers from the ... Read pageThe Paleozoic: Cambrian, Ordovician, Silurian: This ancient era, the Paleozoic, lasted about 290 million years ... Read Paleozoic: Devonian, Carboniferous, Permian: In the second part of the Paleozoic, the emerged lands are divided into two ... Read page The Mesozoic period begins: the Triassic period: This intermediate era in the geological history of the Earth lasted about 185 million years ... Read pageThe Mesozoic: Jurassic and Cretaceous: As the Mesozoic advances, the supercontinent Pangea is fragmented; this favors theā€¦ Read pageThe Paleogene: Paleocene, Eocene and Oligocene: The most recent geological era, the Cenozoic Era, covers the last 66 million ... Read pageThe Neogene: Miocene and Pliocene: Neo is the second of the three periods in which The Cenozoic Era is divided ... Read pageThe Quaternary: Pleistocene and Holocene: The Quaternary is the last Cenozoic period that began 2.59 million years ago and ... Read page