As a follow up to my previous post reviewing the history and potential future of iron in human civilisation, I wanted to take my thoughts further by considering the practical alternatives to metallurgy and future possibilities that could open the door to whole new types of civilisations based on biology rather than technology. I will focus on the production of cutting edges here, and maybe return to alternatives to metal for other purposes such as fasteners and water and hear proof containers.
Metal production usually follows a predictable path, starting with gold which is found as a pure metal in nature that is soft enough to shape into various ornamental objects. Silver and copper are easily converted from ore into metal by low temperature smelting, but neither are strong enough to produce functional tools. Only the addition of tin can produce bronze, which is strong enough to produce tools and weapons. Surface tin and bronze deposits usually occur far from each other, so this technology demands sophisticated trade networks. With the production of high temperature furnaces and the use of chemical reduction through charcoal or coal dust, iron ore can also be smelted into even harder objects, whose properties can be further refined by addition of other elements to create a range of specialised alloys.
This process played out first in the near east, then east Asia, and finally in west Africa, catalysing the spread of the three dominant old world farming cultures of the last ten thousand years. The larger empires of the new world were just beginning to produce bronze tool heads around the time of European contact. Metal working was absent from Australasia and Polynesia until recent times. Despite the general lack of metal tools, the cities and societies of the new world were admired as being more beautiful and orderly than those of Europe by the earliest explorers, proving that metallurgy and civilisation do not need to go hand in hand.
For the production of cutting blades the new world societies mined large amounts of obsidian, a shiny black volcanic glass, and learnt how to fashion it into a wide range of objects including polished obsidian mirrors. Obsidian fragments were fixed into weapons with resin. Obsidian blades are still used in surgery today since they are sharper than steel. The effectiveness of obsidian blades was one possible reason for the limited adoption of copper in the new world. Other types of rock were also widely used before the spread of metal based technology, but like any mined resource suffered from limited and depleting reserves, and the inevitable long distance trade of the best quality resources set up geopolitical tensions (though fresh volcanic eruptions produce a steady obsidian supply). It is often joked that the stone age didn’t end because people ran out of stones. This perspective doesn’t stand up to scrutiny. Building with stone is now the sole reserve of the ultrawealthy and powerful governments. Primitive technology enthusiasts often report that they prefer working with high quality stone tools over their metal alternatives, but the resource base and the human skill and attention needed to work stone are both limited. Metal tool manufacture and use are ironically a lower skill set than stone working since they are more suitable for mass production and standardisation. A more renewable alternative could be the production of blades from ceramic and glass, though both rely on access to specialised starting material that face their own depletion issues.
A future civilisation could be better off if it finds forms of technology that do not rely on the mining of non-renewable resources and their trade. The ideal technologies could be produced by the people using them, no matter where they are located. A good example of this is the use of wooden tools. Hardwood digging sticks, often hardened by careful application of fire, are a mainstay of agricultural systems the world over. More recently scientists have subjected wood to fairly simple chemical processes and compression to make blades that are sharper than steel.
Bone was an important material for tools in preindustrial times, fashioned into knives, scrapers and needles. Goat jaws, with their row of sharp hind teeth, were the original hand sickle for harvesting the first domesticated grasses. Perhaps goats could be bred to enhance this trait. In pre-Columbian North America bison shoulder blades were used to create hoes. Recently, some animals were found to incorporate biologically deposited iron into their teeth to enhance their cutting power. Beavers have rust stained teeth for this reason, but the same effect with zinc and manganese has been found in the jaws of wood boring beetles. There is no reason that rodents and beetles couldn’t be selectively bred to produce high quality cutting blades for human tool production. Another potential source of biological cutting tools could be in the shells of various snails. Polynesian societies used turbo shells for scrapers and giant clams for adzes wherever basalt was not available. Humans own bones are underutilised tools too. The skeletons of the first urban basket weavers were identified by distinct wear patterns in their teeth from years of toil. Humans often use tools to excess: our jaws fail to develop properly due to eating too much machine softened food, which causes a range of life limiting health issues.
Often technology is invented to paper over the management of insufficiently domesticated species. We weave a fine basket to gather tiny seeds from shattering grass heads, or we can continue to domesticate the grass into something resembling maize that needs no such technology. The same could be argued for our current use of cutting blades. We go to great lengths to forge axes and pruning saws to manage the towering fruit trees, rather than selecting forms that only grow to human compatible heights. Often the best tools are firmly attached to willing workers. Humans can use cattle and sheep to manage grasslands, and goats and pigs to manage forest understories. As outlined in my book “Taming the Apocalypse”, humans lack a domesticated animal capable of managing mature forest canopies. This has made us dependent on overuse of fire and axes to manage forests which were once maintained by abundant megafauna (mostly driven to extinction by humans in the last 50 thousand years). The full domestication of elephants to partner with humans in managing forest density and health could be a key ingredient in making agroforestry viable.
Another crucial step could come from breeding plants that can be managed by humans without the need for tools. Biomass plants that are brittle enough to be harvested by human hands could be a breakthrough. Some species like cassava show what is possible on this front. Aromatic brittle shrubs like Plectranthus could be bred for their allelopathic properties, planted in groves to suppress weed growth, then easily snapped and piled up to prepare a weed free growing space. Better yet, the crops could be selected for tolerance of residual allelopathy to make management easier. Biomass grasses with leaves that pull out cleanly could also be an option. I love my icecream bean alley systems for their ability to create a weed free understory, but they require a lot of labour to cut back in preparation for cropping. A deciduous overstory species could be developed which drops its canopy at the right time to allow an annual or understory perennial crop to grow once a year, comparable to the bluebells that thrive in deciduous temperate forests. Finally, fire tolerant biomass species could be bred which are burnt periodically to create a fertile growing environment, where the biomass species rapidly regrow once the crop is complete.
It is often said that necessity is the mother of invention. Unfortunately, that means that human cultures often coast for thousands of years on the back of “good enough” solutions, which means they miss the opportunity for alternative approaches. I believe our talent for developing mechanical, technological solutions to our day-to-day problems has hindered our ability to keep experimenting and innovating, especially in societies that push themselves to the edge of the current carrying capacity such that no resources can be risked or spared for further tinkering. The new world civilisations gave us a small hint of what is possible when metal, wheels and large domestic animals are not part of the mix of solutions. I believe much more profound changes in the foundations of our societies are possible, if only we can find a path forward to a more nurturing and open-minded culture. The cultural impacts of the end of industrialisation may be just the catalyst that we need to achieve that kind of transformation.
"Surface tin and bronze deposits usually occur far from each other..."
I'm sure you see the issue here. 😃
Shane, I am intrigued by your statement, "The larger empires of the new world were just beginning to produce bronze tool heads around the time of European contact." Would you share your source for this? I am aware of "coppers", decorative, hammered copper panels in the North American Pacific coast cultures from the Tlingit in the north to the Salish in the south, and the Innuit groups that were called, "Copper Eskimo" by early European explorers, but I have not heard of any evidence for bronze smelting or casting technologies. I am less familiar with SA groups and the Inca clearly had extraordinary gold mining and working capabilities, so perhaps they were moving toward bronze metallurgy?