Sharp stone technology chipped over three million years allowed early humans to exploit animal and plant food resources. But how did the production of stone tools -- called 'knapping' -- start?

Jim and Amy Crawford farm flowers, fruit and food at their regenerative farm, drawing on science and the synergy of nature.

Bryan Nelson is a science writer and award-winning documentary ... Nelson contributed to Mother Nature Network (now part of Treehugger) for more than 11 years, covering a wide variety of topics ...