Early writing is a tale of two scripts. Egyptian hieroglyphs and Mesopotamian cuneiform both emerged independently about 5300 years ago. The political powers of ancient Egypt and Mesopotamia flourished in the centuries to come, partly because writing helped states control the flow of goods and consolidate power. The pen (or ancient stylus) was mightier than the sword. Or so the conventional story goes. But there is a glaring omission here because, at the dawn of writing, there weren't two scripts. That third, mysterious script, called proto-Elamite, appeared in ancient Iran while cuneiform and hieroglyphs were both in their infancy - and has been shockingly overlooked by all but a handful of scholars since its discovery 125 years ago.

Hundreds of languages, from English to Hindustani, are all derived from a single ancestral tongue. Now DNA from ancient bones suggests that the people who spoke this ancient language lived somewhere south of the Caucasus mountains in western Asia. Languages evolve and diversify, much like biological species. Today, about 3 billion people today speak an Indo-European language, such as English, Spanish, Hindustani and Nepali. All these languages are descended from a single common ancestor.