What was the contribution of $W. C. Pei$?

Low and sloping forehead,skull with thick bones,deep lower jaw,and absence of chin were characteristic features of which of the following?

$A$: The brain reaches between $75$ and $80$ percent of its adult size within the first two years,and its full size at the age of $6$ years.
$R$: From an evolutionary point of view,the human gestation period is believed to be shortening.

Which of the fossil man possessed a cranial capacity almost equal to that of modern man?

Write a short note on the evolution of man.

The first human ancestor whose fossils were discovered is: