Origin of the Earth and the Geological Ages
The history of humans is closely related to the
history of the earth. The earth contains geological, archaeological and
biological records of historical times in its upper layers. They are important
for reconstructing the history of the earth and various living organisms. The
fossil bones of the human ancestors are embedded in the earth’s layers.
Palaeoanthropologists and archaeol-ogists excavate
the soil and rock layers on the earth and extract evidence about hu-man
ancestors. These layers and the fossils are scientifically dated to study the
various stages in human evolution and prehistory. Through the gathered
evidence, they at-tempt to understand the evolution of hu-man history and
developments in a chron-ological order.
Archaeology is the study of human past through the analysis
and interpretation of material remains.
Palaeoanthropology is the study of the human ancestors and
their evolution by the study ofthe fossil remains.
The earth was formed approximately 4.54 billion
years ago. Gradually, conditions emerged for the growth of organisms. Then
plants and animals came into being, and thereby foundation was laid for the
evolution of humans. The long span of time in earth’s history is divided into
eras, periods and epochs by the geologists
The earliest trace of life in the form of
microorganisms emerged 3.5 billion years ago. The primitive multi-cellular form
of life first appeared in the Proterozoic era, about 600 to 542 million years
ago. In the Palaeozoic era (542 to 251 million years ago), fish and reptiles
along with various plants appeared. Dinosaurs existed in the Mesozoic Era (251
to 66 million years ago). Australopithecines (literally ‘southern ape’)
appeared in the Cenozoic era, which commenced about 66 million years ago.
Australopithecines were the apes from which modern humans
evolved. Now they are extinct, but they are considered to be the close
relatives of humans.
1 billion = 100 crore
1 million = 10 lakh