Nearly 4,000 years ago, Semitic-speaking workers at Egypt's turquoise mines in the Sinai borrowed a handful of hieroglyphs to write the sounds of their own language. This 'Proto-Sinaitic' script is the ancestor of Phoenician, and through it of the Greek, Latin, Cyrillic, Arabic and Hebrew alphabets. The letters you're reading began as miners' inscriptions.
In Kuşköy, a mountain village in northern Turkey, people talk across valleys by whistling Turkish. A 2015 study showed that whistled Turkish draws on both hemispheres fairly evenly, whereas spoken Turkish relies mostly on the left. The physical form of the signal, it turns out, matters to the brain.
Speech has no gaps between words. In 1996, researchers played 8-month-old babies a continuous stream of made-up syllables for just two minutes. The infants picked out the 'words' by tracking which syllables tend to follow one another. That's probability calculation, done without a calculator or any visible effort.