A clip from the BBC series, How to grow a planet, describes how a mutation in a wild grass (einkorn) led to the wheat that sustains many modern humans. The source of all modern wheat has been traced to this area in Turkey. This is also the site of what has been called the first temple, Göbekli Tepe. Was it built by farmers or settled hunters? It's changing the way we think about the beginning of agriculture.

• Video, about 10 minutes