This might be prehistory, and as such out of this sub's scope, but I was wondering if we know how the knowledge of fire creation spread. Were people of the time so centrally located that the innovation was easily passed or is it known/assumed a few people figured it out at a similar time?
To add clarity, I'm curious about starting a fire from "scratch" with two sticks or a flint, and not referring to controlling a fire that had been started naturally I.e. dry conditions or lightning.
When hominids first learned to make fire is a hotly debated topic. Most archaeologists agree it was sometime between 12k years ago and 400k years ago. Which narrows it down considerably as humans have been using fire for about 1.5 million years.
There are two competing views on the first tool used to make fire. The hand drill (twisting a stick rapidly while pushing it into another stick with some kindling) or flint and pyrite which would be an early version of flint and steel.
Flint and pyrite seems to come from Europe while various forms of drilling come from Africa and Asia. The natives of North America extensively used forms of drills and so are thought to have brought this with them from Asia.
About 100k years ago we have an explosion (pun intended) of fire use throughout Europe. Some people suggest this is evidence of knowledge of fire making. Others suggest that breaks in the record of fire use indicate that this was simply control of naturally occurring fire.
It should be noted though that knowledge of how to make fire did not mean that people began making a new fire every night. It was not until the invention of the match in the early 19th century that starting a fire from nothing became a common method. Prior to this fires or coals would generally be kept burning so that fire didn't have to be made.
Non scholarly article that sums it up nicely for a quick read
Flint and pyrite: making fire in the Stone Age