Geological Time Scale

Formation of cells depends on conditions of planet earth.The conditions of lithosphere and atmosphere during formation where not fit for existence of life.Formation of techtonic plates and changes in atmosphere are linked with evolution of life.From single cell to multicellular organisms like human being is always associated with changes in lithosphere and atmosphere which is defined as geological time scale.This is a calendar of evolution of life combined with changes in planet earth.The calendar is divided as era, period and epoch.Haeden and archean period are defined as pre cambrian.The paleozoic era is divided as cambrian, ordovician , silurian ,devonian,missisipian,pensylvanian and permian.Haedan peroid and part of archean period forms the Azoic era which is also included in pre-cambrian.Part of archean is known as proterozoic.Next comes the mesozoic which is divided into triassic,jurassic and cretaceous.The final peroid is cenozoic which is divided into tertiary and quarternary peroid.
In this video these time scale divisions are discussed with regard to lithosphere and atmosphere.During all these periods the changes in evolution of life forms are discussed in consecutive separate videos.