And it’s not just the sheer number of varieties, but also how incredibly accessible and nutrient rich that they are. It always feels to me like magic that I can eat entire meals for weeks at a time just off the land in the northeast during the spring, summer & fall seasons. It feels like someone tweaked things to grow these kinds of plants specifically for easy human consumption.
Then again, could be I’m just overthinking. :o)
By being edible, tasty and nutritious, the likelihood of an animal eating the fruit and spreading the seeds is increased, and so both the animal and the plant wins.
We don't dump our crops in bogs, nor bones of cattle. In fact we plough the crop remains into the dirt for the health of the soil, and we grind up the bones of food animals for feed and other uses.
All of our buildings and works would disappear pretty fast, and a simple ice age scours the earth very effectively.
13k years is maybe not enough without an ice age, but in 50k years? No trace, except they'd think a meteor struck and caused a mass extinction event.
(I'm not even sure our last 200 years, where we really expanded, would even be a blip in fossil records)
We've found 0.4 million year old wooden javelins in peat bogs. Beyond that, we have intact dinosaur nests with eggs, 100 million years old, and these were not ground down to powder by glaciers. If there were any non-stone-age civilizations older than 10,000 years, their residue would be visible.
I know a load of human remains and accouterments were found in bogs.
Regards to the glaciers, I suppose there are ranges of effects. The Canadian Shield had all topsoil shorn away, in most places even now it's just a few feet of soil then granite.
https://en.wikipedia.org/wiki/Canadian_Shield#Ecologyq
In such areas, nothing survived. Shell middens would be wiped away.
I may have over stated, but my point was it won't be as easy as some think.
Children of a future civilization might not find out anything about our culture or language, but they are definitely going to know that we loved oysters. Meanwhile, their scientists will argue about what kind of iron-rich oysters are responsible for the remains of reinforced concrete along our prehistoric shores and rivers.
We're not talking about people living in mud huts who only eat fruit, haven't discovered fire, and leave no archeological traces; likewise we're not talking about hyperintelligent dolphins who went extinct, or aliens that landed briefly 4 billion years ago on a continent that got subducted. If you want to talk about the non-discoverability of something that isn't an advanced civilization, go ahead, split that hair.
The next ice age we have is not going to remove any of Canada's open pit mines. https://en.m.wikipedia.org/wiki/List_of_open-pit_mines
On that note, I once met someone who claimed to have found a piece of carved glass in the bushland peripheral to the city which would have dated from the period of initial contact between Europeans and aboriginals. He told me where it was found, in general terms, which is extremely inaccessible and thus it's still probably there - waiting for a rediscovery.
Further on that note, the main difference between hand grinding and initial machine grinding is a reliable rotary axis which generates a degree of symmetry and precision in the workpiece (due to the rotation about a fixed axis) not otherwise available to hand made tools. This is the general basis of all machining, ie. the use of a relatively precision ground reference plane or relative precision reference geometry to achieve precision work. Perhaps it can be said that it was the transition of an energy source to precise rotary motion (such as is used on pottery wheels and presumably very early lathes and grinding equipment) which sparked the industrial revolution and the modern era.
Amazing that the aboriginals of Australia had ~45,000 years (or ~1000 generations) of relatively stable presence but apparently never decided to invest in fixed machines for precision work. I guess this was because there is no evidence they ever had a wheel, which is a prerequisite, though anthropologically one might safely assume they frequently used round shape seedpods, stones or other naturally occurring elements to meet specific technical needs thus perhaps had no need to fashion artificially round elements. One may further suppose their seasonal lifestyles probably emphasised portability and reworkability in technological techniques over precision which probably offered very little in the way of benefit when you were, for example, spearing prey at relatively close range. After all, who wants to carry a machine hundreds of kilometers? Much better to build a new tool when you arrive.
Finally, I have a small ethnographic art collection focused on the Pacific. One of my better pieces is a very long hardwood paddle from the Sepik River of Papua New Guinea featuring immensely complex hand-carved scroll work and carved out of a single piece of solid timber. However, the shaft itself is clearly slightly off straight. Even in cases like this, where the inertial force of an entire boat and its contents would be presumably transferred through the paddle when navigating or stopping by poling off the river bed, extremely experienced and ancient traditional woodworking cultures would still clearly accept inconsistencies. One assumes that picking the right wood (knowing which tree to fell) and how to prepare, treat or store the timber was probably of greater functional utility to producing a useful and lasting tool than absolute geometrical accuracy.
Thus perhaps our current industrial obsession with precision machining is just largely irrelevant to a pre-metal age in which maximum forces were order of magnitudes lower.
possibly, but very early lathes are at least new kingdom and probably old kingdom egypt, so if so it took over 3000 years for that spark to blaze. grinding is much older than that, 44000 years old in australia
precision grinding was crucial to making the pyramids, though those aren't pre-metal. it's also useful for keeping mice out of your stored grain. generally, imprecise construction is liable to collapse on people and kill them, so you'd expect to find precision measurement as soon as you find cities (neolithic), but that is more speculative
the paddle's curvature may be intentional; it reduces impact loads