I only annotated four of my references. Re: https://aeolipera.wordpress.com/2021/10/22/re-efficient-production-of-neanderthal-birch-tar/
Citation
P. Schmidt, M. Blessing, M. Rageot, R. Iovita, J. Pfleging, K. G. Nickel, L. Righetti, and C. Tennie, “Birch tar production does not prove neanderthal behavioral complexity,” Proceedings of the National Academy of Sciences, vol. 116, no. 36, pp. 17707–17711, 2019.
Explanation
This study demonstrates that birch tar is deposited on nearby surfaces when birch bark is burned, and does not require oxygen-depleted environments. This implies that it could be discovered easily and reproduced readily by anyone who can gather birch bark and make a fire, which repudiates the theory that birch tar is evidence of Neanderthal general intelligence. The researchers argue this case comprehensively by producing tar under likely conditions (a fire next to a stone wall), quantifying the amount produced, matching the chemical analysis of the produced tar with archeological tar, and testing the mechanical strength of tools hafted with the tar. Notably, the tar was produced at 600-700 degrees Celcius (due to the presence of oxygen), which probably contradicts one of my other sources that claims such tar can only be produced in oxygen-deprived conditions at near 350 degrees Celcius.
I used this article to present a contrasting view to my perspective. By arguing that evidence of efficient production is evidence of quality thinking, rather than mere invention, I sidestepped the facts presented by these skeptics, which freed me from the necessity of debating its particular findings. Producing large amounts of tar is quite another thing from producing “usable” amounts.
Citation
P. R. B. Kozowyk and J. A. Poulis, “A new experimental methodology for assessing adhesive properties shows that Neandertals used the most suitable material available,” Journal of Human Evolution, vol. 137, p. 102664, 2019.
Explanation
The majority of this study covers the mechanical properties of adhesives that are likely to have been available to Neanderthals. The remainder presents the time and resource investment that would have been necessary to produce quantities of them. It concludes that birch tar was the most advantageous material for stone tools but also considerably more difficult to produce than alternatives, which indicates a significant up-front investment but also a more economical choice overall. The authors present this as evidence in favor of Neanderthal trial and error, which is necessary to my claim that the production method shows an understanding of cause and effect. This thesis was particularly fortuitous because it spared me the necessity of arguing that claim myself. That and the source showing that Neanderthals produced large quantities of tar were sufficient to meet the definition of engineering, which I implied is a type of quality thinking.
Citation
M. J. Niekus, P. R. Kozowyk, G. H. Langejans, D. Ngan-Tillard, H. van Keulen, J. van der Plicht, K. M. Cohen, W. van Wingerden, B. van Os, B. I. Smit, L. W. Amkreutz, L. Johansen, A. Verbaas, and G. L. Dusseldorp, “Middle Paleolithic Complex Technology and a Neandertal tar-backed tool from the Dutch North Sea,” Proceedings of the National Academy of Sciences, vol. 116, no. 44, pp. 22081–22087, 2019.
Explanation
This study analyzes and dates a 50,000-year-old hafted flint flake from the Northernmost range of Neanderthal expansion during the Middle Paleolithic, and discusses the implications of these findings. The flake in question is identified as a “domestic” type of stone tool, i.e. a convenience and not a necessity for survival. It was hafted with birch tar in spite of small group sizes, high environmental stress, and high residential mobility (vagrancy), which indicates that birch tar was produced efficiently enough that unnecessary hafting still conferred fitness under these conditions. This provides evidence for my claim that the birch tar production process was efficient, which is the second part of my argument that it meets the definition of engineering (and therefore quality thinking).
Citation
T. J. Koch and P. Schmidt, “The formation conditions of birch tar in oxygen-depleted environments,” Archaeological and Anthropological Sciences, vol. 13, no. 6, 2021.
Explanation
This study presents a number of findings that undercut the claims of the Schmidt et al. study I used as a contrasting perspective. It is not strictly necessary to my argument but I included it because it provides a secondary reason (behavioral complexity) for my overall claim (quality thinking), which makes it more reliable, and because it is problematic to the group I identified as “skeptics” in the writeup. In particular, the researchers demonstrate that birch tar can only be produced in a temperature range of 350-400 degrees Celcius (contra Schmidt et al.), which implies the absolute necessity of air-constricted conditions to prevent burning. Another useful finding is that maximum birch tar yield can theoretically be achieved 15 minutes after reaching the working temperature, which yields insight into how efficient production could have been achieved.
The authors suggest that their production method most closely approximates Neolithic single-pot and Middle Paleolithic earthen pit methods of birch tar production. Though it is not discussed in this study, it’s notable that we have not found evidence of Neanderthal ceramics from the Middle Paleolithic (as in the “domestic” flake mentioned in the annotation above). Without portable ceramic vessels, the production process would have had to be even more efficient because it would require the creation of an earthen pit at each site, which significantly increases the time of each working session. All this is unnecessary to my original argument, but it is useful to include because it buttresses my conclusion and implicitly casts serious doubt on the objections and findings reported by researchers from the opposing perspective.
Aeoli Pera 