I m being confused of it...
that, it is said that firstly the early humans were tall and big in size, they live long life.. but recent humanity is smaller and no longer can live approximatelly before 100 years old dies..
so my Question's concept is just what was the reason of that period they were completely change from us..?????

and also please clear it that... I have heared that the Atoms and Cells of that period were bigger than recent, therefore they were as large. IS it correct concept????

By: A student of Science from Pakistan

early humans were small - from skeletal remains probably less than 5 foot. that is not surprising given the lack of food and poor health that would accompany poor hygiene. The consequence of that would be their life expectancy would be much shorter than modern humans - probably 30 years at most.

the size of atoms is thought to be constant since the birth of the universe. similarly there is no reason to think that the size of cells of any given species have changed over time.