To try to pin down the earliest evidence of controlled fire use, Paola Villa at the University of Colorado in Boulder, and Wil Roebroeks at Leiden University in the Netherlands re-examined the data from over 100 European sites. They were looking for evidence of fires that were unlikely to have occurred naturally – those in caves, for example – and for clues that fire had been used in a controlled way. These include activities such as making pitch: some early hominins made this sticky substance by burning birch bark and using it to glue pieces of flint to wooden handles to make stone tools easier to use.She continues:
Although Villa and Roebroeks investigated only European sites, they think evidence of controlled fire use at a number of other sites is also up for debate. The Swartkrans site in South Africa is believed by some to contain 1.6 million-year-old evidence in the form of hundreds of charred bones. "But these might just have been sporadic natural fires that were taken advantage of," says Villa. In fact, just one site earlier than the 400,000 year mark has strong evidence of controlled fire use, the pair says: the 780,000-year-old Gesher Benot Ya'aqov site in Israel.The earliest evidence in Asia is in the Homo erectus/ergaster site of Zhoukoudian, where it is estimated to be around 400 ky also. This does, indeed, suggest that early humans use of considerable resourcefulness without the use of fire. I am betting though, that even Spain during the Mindel and Riss glaciations was pretty cold. I would not be surprised if evidence was discovered that pushes the use of controlled fire back a bit.