Which of the following had the lowest brain capacity during human evolution?

Which of the following represents the correct chronological order of human evolution from the earliest to the most recent?

Which human ancestor succeeded the Neanderthal man about $50,000$ years ago and became extinct about $20,000$ years ago?

The stage next to $Homo$ $habilis$ was:

The cranial capacity of $Homo$ $erectus$ was approximately ........ .

During the evolution of man, many changes have taken place in his ancestral characters. Which one of the following is an insignificant change?