Human evolution: using fire to improve stone tools (Introduction)

by David Turell , Monday, October 05, 2020, 18:05 (1510 days ago) @ David Turell

In a cave in Israel the stone tools were studied:

https://www.jpost.com/archaeology/israeli-study-finds-ancient-hominins-used-fire-to-mak...

"In an article that appeared Monday in Nature Human Behaviour, researchers at the Weizmann Institute of Science in Rehovot detail how they employed cutting-edge technologies to take a fresh look at a collection of ancient stone tools. Their results suggest that the early humans who made them may have had a good understanding of the effects of heating the stone before flaking it into blades and may even have used a variety of temperatures to create different types of tools.

"Qesem Cave, a site in central Israel, was excavated by Prof. Avi Gopher and colleagues at Tel Aviv University, and the findings from the cave have been dated to between 420,000 and 200,000 years ago – the Lower Paleolithic period – and it is assigned to the unique Acheulo-Yabrudian Cultural Complex.

"The ancient hominins, a group that includes modern humans as well as extinct human species, who lived in Qesem Cave, left behind tens of thousands of stone tools. These tools are mainly made of flint, a material which is readily available all over the country, and they were produced in a process called knapping, a process that uses another rock or tool to chip off pieces, honing a sharp edge.

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"They compared three different types of flint artifacts, and revealed three unique temperature ranges, one for each kind. The first type, which the scientists call “pot-lids,” were small, nicked and chipped shards, and the analysis showed they had been exposed to fire hot enough to cause pieces of the flint to fly off on their own accord. That told the team their analysis was on the right track, as it had been suggested in other studies that very high heat – up to 600 degrees Celsius – had been suggested, created the nicks and chips. The second type of pieces are known as flakes and the third are the blades, larger, knife-like tools with one long sharp edge and a facing, thicker edge where they can be held. Flakes, essentially smaller cutting tools than the blades, had been treated at a relatively large range of temperatures while the blades had been heated to lower temperatures and the temperature range they had undergone was much smaller. In other words, it appeared as though the cave’s inhabitants had intentionally used different heat treatments to create different tools.

“'We can’t know how they taught others the skill of toolmaking, what experience led them to heat the raw flint to different temperatures, or how they managed to control the process, but the fact that the longer blades are consistently heated in a different way than the other pieces does point to an intent,” said Natalio.

"Pinkas said, “And that is technology, as surely as our cell phones and computers are technology. It enabled our ancestors to survive and thrive.'”

Comment: It can not be known exactly when the inventive technique developed, pre-sapiens or by sapiens. but it shows a marked level of clever thought and experimentation.