1. Introduction

The Prehistoric period refers to a long span of time preceding the appearance of recorded history in the form of written accounts by man. That means it describes eras where there was human existence, but there is no records exist about their way of life. But when prehistory is used more broadly, it also can refer to a period when life appeared on earth even before the existence of human beings.

After being through the decades of years of researches and calculations, scientists like geologists were hypothetically estimated the age of Earth approximately about 4.54 billion years old. Fossil evidences informs most studies of the origin of life on Earth. In 2017, fossilized micro-organism or microfossils were announced to be discovered in hydrothermal vent precipitates in the Nuvvuagittuq Belt of Quebec in Canada which may be as old as 4.28 billion years old which became the oldest record of life on Earth ever suggesting that it was an almost instantaneous emergence of life after the ocean formation around about 4.41 billion years ago, which was not so long after the formation of the Earth.

Scientists estimated that our planet Earth has becoming a home for almost 10 million different forms of life. Out of these 10 million species, only one species is called Homo Sapiens Sapiens, that is the human beings, which are the most curious creature on the Earth. We, humans beings are very curious to know about our past and future. Our need to know something overwhelming facts like who are humans? Where did we come from? How did our ancestors look like and so on..

In order to figure out the above mentioned profound questions, Archaeologists and Anthropologists dig into the dirt, collects DNA samples, examine artifacts and try to construct a picture of our ancestors which were extinct have been walking upright on two legs for at least six million years ago. This led a few questions arises in our minds, that is, What did the Earth look like about six million years ago? Who lived here? How did they look like and etc..

Digging into our ancestor's past is a very tough job and need to work hard. Records of human life were not kept millions of years ago. After all, we have an evidence of life which was about 30,000 years has been found in cave painting, on burial chambers and in the form of crude tools. But actually, the story of human evolution has began in Africa about six million years ago and it describes the very long process that our ancestors went through to ultimately become modern humans. This process has been uncovered by studying fossils and understanding the underlying theory of evolution.

But these fossils explains about the early hominids who were lived in Africa about two to six million years ago, which has began to walk upright by using only two legs or bipeds. These hominids comprises the modern human today, the extinct ancestors and apes that shares similarities with humans. those who study the earliest hominids of about six million years ago do know that these human ancestors physically changed in response to their environmental surroundings. And yet, the species to which we, modern humans, were belongs is Homo Sapiens Sapiens which is only about forty thousand years old. Hence, it was a very long evolutionary process which results from six million years ago hominids to forty thousand years old present modern human being which was known as Hominization.