We are the result of a short series of discrete mistakes that made us what we are today. Our descent from other apes in the last few million years or so boils down to a mere handful of genetic and morphological turning points. These small changes incrementally built on each other, as in a multiplayer game in which the outcome is never quite

The picture, in the end, is of an odd species that stumbled into global dominance through a relatively quick succession of simple mistakes. A species forced to speak up, or let its helpless infants perish.

I will argue here that talking and caring for underbaked newborns co-evolved, in an episode of runaway selection initiated by the genetic anomalies we now know spurred our species' neurological growth.