“In Pain Shalt Thou Bring Forth Children”

“So far as I know,” writes Carl Sagan, author of The Dragons of Eden—Speculations on the Evolution of Human Intelligence,^a “childbirth is generally painful in only one of the millions of species on Earth: human beings.”

This is because of the comparatively large human skull, which, in turn, was required by the increase in the size of the human brain, or more particularly, of that part of the human brain known as the neocortex. The neocortex is the largest and most dominant part of the human brain. To it may be traced those characteristics which we regard as most distinctively human, including our moral sense.

The American anatomist C. Judson Herrick describes the spectacularly fast development of the human neocortex in the Pliocene/Pleistocene period: “Its explosive growth late in phylogeny is one of the most dramatic cases of evolutionary transformation known to comparative anatomy.”

Of course this increase in cranial volume required a correlative increase in the braincase or skull. Sagan notes that modern men and women have a braincase twice the size of Homo habilis, an evolutionary cousin of Homo sapiens, that went nowhere in evolutionary terms and became extinct.