Question

human evolution began approximately 7 crore years ago

Answer 1

It is true that human evolution began 7 - 10 million years ago. Theories like the 'The Origin of Species' by Charles Darwin suggested that humans emerged from the apes who lived in the African regions which was confirmed by the study of the 3-4 million old Australopithecus fossils. Genetic studies and studies of the fossil evidences by methods like radio-dating, etc. has confirmed these theories. 

Studies by paleo-anthropologists on different types of fossils from different regions have led to the theory of evolution of man from apes which have been recorded in the evidence book.

Answer 2

no it was about 3.8 billion year ago when first bacteria and blue green algae came to existence