The Origins of Life (Milions of years ago)

Earth's Formation

4500 BCE

The Earth was formed as part of the birth of the solar system; what later became the solar system initially existed as a large cloud of rocks, rocks and gases in rotation. It was composed of hydrogen and helium produced in the Big Bang, as well as of chemical elements expelled by the explosions of supernovae. With time it was formed until it is now.

The first Organic Molecules

4000 BCE

The origin of life in biology is the way and the era in which life originated. This is a controversial topic and has philosophical and theological implications; It is difficult to establish the specific mechanisms due to indirect analysis.
Among the scientific community, the theory that life evolved from inert matter at some point now seems to be well established between 3,900 and 3,500 million years before nowadays.

Life appears (Prokaryotic Cells)

3500 BCE

The first cells that populated the Earth, already 3,500 million years ago, were prokaryotic cells (archeobacteria), that is to say, that they did not have internal nucleus separated by a membrane that collects the information of the DNA, and were probably heterotrophs that obtained the energy of the fermentation of the organic molecules present in the primitive ocean.

Oxygen in the air

1800 BCE

It is assumed that oxygen in the atmosphere has a photosynthetic origin. In the primitive atmosphere there was no oxygen, and the first photosynthesizers generated it. But there are no anaerobic photosynthesizing organisms, since both plants and algae and cyanobacteria breathe with oxygen. So, what type of organism is supposed to be the one that began to photosynthesize, but did not have oxygen to breathe? It is not certain that anaerobic photosynthetic organisms exist.

First Eukaryotic Cells

1400 BCE

Prokaryotic cells were the main characters of terrestrial life for 2,000 million years and had time to improve their metabolism. But 1,400 million years ago the first eukaryotic cell appeared, that is, a cell that has a nucleus with its genetic information. For the appearance of this first eukaryotic cell, the appearance of a plasma membrane that independized DNA was necessary.

Multicelullular Organisms (Cambriam life's explosion)

600 BCE

Multicelular organisms are organisms that consist of more than one cell, in contrast to unicellular organisms

First Vertebrates

500 BCE

The first vertebrates appeared inside the water with forms that have simmilarities with the actual fishes. They were very simple , far form what the vertebrates are now.

Dinosaurs and Mammals coexist

200 BCE

Dinosaurs and mamals coexist 200 milions years ago, and this date is so important because means the coexistence of prehistoric animals, with the primitive forms of the animals that we have nowadays.

Primates appeared

65 BCE

They are an oreder of mamals that had habitate the earth since 65 milions years before now. Humans are part of primates, and the most similar specie with us is the chimpanze.

Dinosaurs Extinction

65 BCE

It was a very important succes in history. There's several theories about how they extinct, but the most popular one, is that a meteorite impact on the earth surface and as a consequence of that, all dinosaurs get extinct, the mamals could survive because they didn't need the much energy that the dinosaurs need.

Homo Erectus

2 BCE

The real date is 1,8 mil·lions years ago, and this specie was the first that could walk cammed. It was the specie that goes just after the Homo Habilis, and it's the predecessor of the Homo Neandertalis.

Nowadays

2018