Homo sapiensneanderthalensis and Homo sapienssapiens (Cro-magnon man), were originated from

The best description of natural selection is

Assertion : From evolutionary point of view, human gestation period is believed to be shortening.

Reason : One major evolutionary trend in humans has been the larger head undergoing relatively faster growth rate in the foetal stage.

Which one of the following gas was not present in free form at the time life originated on earth?

Organic compounds first evolved in earth required for origin of life were