Evolution of the Earth: Evolution of the Earth: Evolution is a process of gradual growth and development of life on the Earth from simple to complex form. Evolution of the Earth started around 4.5 billion years ago, when our solar system took shape due to the massive explosion of a small molecular ball called the Big Bang. During the evolution phase, the Earth went through many changes, for example: invasion of the land by oceans, uplift of mountains, erosion and ice age. Some of the initial forms of life were unable to withstand these extreme conditions and got extinct. But fortunately, they left some tiny traces of their existence behind in the form of fossils. These traces helped geologists to put together a general idea of the timeline of life.
Eon: Eon means a long period of time which is indefinite or whose duration is not exactly known.
Precambrian Time: The period from which the formation of the Earth started is known as the Precambrian time. The term Precambrian is an informal term and is used for both time and rocks.
Time Period: This period extends from about 4.5 billion years ago to the beginning of the Cambrian period.
Features:
♦ A big part of history is covered in this period, starting from the creation of the planet to the appearance of multi-celled life forms.
♦ Precambrian period is divided into three eons: the Hadean, the Archean, and the Proterozoic.
♦ The oldest known glaciation occurred during the Precambrian time.
