Human evolution: gluing tools (Introduction)

by David Turell , Thursday, February 22, 2024, 16:54 (273 days ago) @ David Turell

Bitumen and ochre don't stick to hands:

https://mail.google.com/mail/u/0/#inbox/FMfcgzGxRnfnxGwbQGxXghLzLXFLtCpq

"When researchers at a Berlin museum decided to reexamine a set of stone tools that had sat untouched in their collection since the 1960s, they were surprised to discover several items covered in curious red and yellow stains. Further analysis of the tools, which were crafted some 40,000 years ago by ancient human relatives in what is now southwestern France, revealed traces of bitumen—a sticky substance used to make asphalt—and a naturally occurring pigment called ochre.

"According to a study published yesterday in Science Advances, Neanderthal toolmakers mixed these two ingredients together to create a surprisingly sophisticated type of glue. When researchers recreated the recipe, it yielded a gummy, malleable adhesive strong enough to hold stone blades, scrapers, and flakes, but not sticky enough to adhere to hands—ideal for making grips for handheld tools.

"While previous research has shown that early modern humans in Africa made compound adhesives using ochre, this new study demonstrates that European Neanderthals were also innovative manufacturers of both glue and tools, and may have had higher levels of cognition and cultural development than previously assumed.

“'What our study shows is that early Homo sapiens in Africa and Neanderthals in Europe had similar thought patterns,” study author Patrick Schmidt said in a press release. “Their adhesive technologies have the same significance for our understanding of human evolution.'”

The original paper:

https://www.science.org/doi/10.1126/sciadv.adl0822?et_rid=825383635&et_cid=5112502

"Abstract
Ancient adhesives used in multicomponent tools may be among our best material evidences of cultural evolution and cognitive processes in early humans. African Homo sapiens is known to have made compound adhesives from naturally sticky substances and ochre, a technical behavior proposed to mark the advent of elaborate cognitive processes in our species. Foragers of the European Middle Paleolithic also used glues, but evidence of ochre-based compound adhesives is unknown. Here, we present evidence of this kind. Bitumen was mixed with high loads of goethite ochre to make compound adhesives at the type-site of the Mousterian, Le Moustier (France). Ochre loads were so high that they lowered the adhesive’s performance in classical hafting situations where stone implements are glued to handles. However, when used as handheld grips on cutting or scraping tools, a behavior known from Neanderthals, high-ochre adhesives present a real benefit, improving their solidity and rigidity. Our findings help understand the implications of Pleistocene adhesive making."

Comment: making a workable compound glue, not sticky to hand is a highly complex invention, which also involved travel to reach each of the ingredients. It shows how bright the Neanderthals were.