What’s the furthest someone (or a small group) could travel back in time on Earth, and still find enough edible plants or animals to live indefinitely? I’m assuming unlimited hunting/gathering supplies (rifles, ammo, nets, cooking apparatus, etc.) and, if needed, ideal placement on Earth. Not fair using heroic levels of technology (no nuke plant and special factory to synthesize food directly from raw materials, etc.), but assume 100% complete knowledge of the available life in the period, so you don’t get poisoned or waste time searching for something inedible.
The question is really about compatibility of human digestion with the earth’s flora and fauna as you go all the way back to 4.5 billion years ago, and at one point do you run into trouble. So, problems with atmosphere, temperature, etc. aren’t considered.
I’d imagine 60 million years ago things would be fine. 250-300 million years ago you’ve got traditional dinosaurs, stranger plants, etc. - still edible? Go back 500 million years, and most animals are still in the ocean (better bring a boat). Go back 1 billion years, and we’re down to single-celled life, but hey, we’re all eukaryotes, right? Assuming you can scrape together enough straining through the ocean, is it still edible? Go back past 2 billion years, and we have cyanobacteria - I’m sure it tastes great, but can you live on it if you can scrape enough together? How about 3+ billion years ago?
So, how far could you go back before the available “food” is too alien to be of use, even if you could catch/collect it and cook it?
No way of knowing what Paleozoic life was toxic to humans and what wasn’t. But assuming that nothing was toxic, there was abundant life in near-shore areas in the early Cambrian–bring a fine net and live off bugs. Be prepared to eat them raw unless you bring along your own wood or other form of fuel (or else be ready to wait for lots of harvested seaweed to dry.) Also, bring along your own oxygen, because there won’t be enough.
I believe today a human can safely eat virtually everything found in the ocean, raw without cooking… So I suppose, based on that analogy, we could get nutrition from many forms of primitive macro-life.
There is no reason to think earlier life forms would be more generally toxic than they are now. If anything, maybe less, because life wouldn’t have had time to evolve the many kinds of toxin present today.
There were arthropods and mollusks and other kinds of marine invertebrates present in the early Cambrian. So you could probably have made shellfish chowder before 500 million years ago.
Some kinds of cyanobacteria such as Spirulina are edible. It is a pretty good source of nutrition but lacks vitamin B12. It might be possible to pick up B12 from other bacterial sources.
Stromatolites, representing large colonies of cyanobacteria, go back some 3.7 billion years so it is conceivable humans could have lived on them if a source of B12 could also be found.
Eating modern reptiles carries significant microbiologicalrisk, and there is no reason top think that would be different going back to early vertbrates. After all, complex bodies make ideal habitat for all manner of bugs, parasites and critters.
Colonisation of the land surface by plants is likely to have begun maybe 500 million years ago [just pushed back a lot in a recent study]. You may want to have a nibble on them, but they were not especially adapted to offer tasty juiciness in return for a hit of pollen or seed dispersal. Probably as appetising as eating pencils, but without the leady goodness.
If us and our food sources have not co-evolved, then its hard to expect that either our eating mechanisms [stupid fragile peggy teeth rather than a good solid parrot-chomper beak], digestive systems or internal defences against god-knows are going to make eating especially effective.
But, if you can sort out cooking to manage the bug risk a bit, a big sea scorpion might give you a hearty lobster-sized meal. Theroe of horse-shoe crabs is still eaten as a delicacy.
Now, that would be ok, until you eat the 15151515’s great, great ancestor of human beings. Then you go off in a puff of smoke or the universe ends or you get into a time loop.
Maybe not, but I can imagine soft-bodied creatures relying on chemical defenses before mineralization was invented. Would you want to be the first person to try an opabinia, or a dickensonia? Also, ideas such as this which–while possibly not making trilobites toxic, sure doesn’t sound like it would make them tasty.
Top predators, though, and those protected by hard shells, would probably not been chemically defended. So eating a Cambrian Anamolacaris or a bivalve would probably have been safe enough.
Since there were no active predators present, chemical defenses would have been unlikely by Ediacarian forms like Dickensonia.
If I recall correctly, there were plenty microbes that thrived (and still do) on sulfates in the early stages of life on earth. There were a lot of them when earth still had an CO2 atmosphere or photosynthesis was not common due to absence of light. Presumably they had sulfur or sulfate in their “bodies”.
Given humans have a limit on how much sulfate they can tolerate, I think this would set the limit on organisms we can tolerate eating from the early earth.
The cyanobacteria that formed the stromatolites would have been photosynthetic rather than using sulfates.
But you bring up a good point: before the Great Oxygenation Event between 1 and 3 billion years ago, there wouldn’t have been enough oxygen in the atmosphere to support human life. So whether there would have been food then is moot.
The kind of plant matter that you would be willing to eat really drops off as you travel farther back than the origin of angiosperms (-160 my). Before that, and you’d have gymnosperms with edible seeds (think pine nuts) and ferns with possibly edible shoots. There would be kelp and other seaweed, too, and maybe some edible roots, but no fruits, grains, or easily digestible leaves. You could try to stave off death by eating mosses or lichens or chewing pine needles, but it’ll be a lot of effort for few absorbable calories.
Hello everybody, I didn’t find the section where to introduce myself so I do that here, hope it will be fine. This is my first post.
There are two things that I’d like to add to this great thread. First: what about the contrary ? In other words, what if a primitive man or woman could travel in time and get to 2018 ? I think that finding food would be the last problem. The real issue would be his/her immune system. We can go back in time but they cannot come here because of bacteria. Our immune system is much more evolved.
There are two things it is necessary to take into account: the difference between our mouth and teeth structure and their one. I don’t think our teeth are strong enough to eat/cut/crumble their food. Second the difference between our and their digestive system. I think we would have serious problems with digestion and, perhaps, even with survival.
This is what came up in my mind reading this thread.
If you just wander into a random wilderness area in 2018 it can be really tough to find food. Sure there are plants and animals all around, but almost all the plants are inedible, and the ones that are edible usually only have a few edible parts and even then only for a short time. And there are animals around, but good luck catching or shooting one.
On the other hand, modern animals are very skittish around humans. Go back to a time when the animals are naive to humans and it might be a lot easier to just walk up and club an unsuspecting critter on the head.
The plants are going to be a lot tougher. Almost all our modern plant foods are angiosperms, although some other plants do sometimes have edible parts, as Euell Gibbons could tell you. “Ever eat a pine tree? Many parts are edible.”
Our immune system hasn’t evolved significantly since the days of “primitive man”, assuming you are referring to homo sapiens sapiens. Our innate immune system developed during the period when we were evolving rapidly and like the rest of our bodies, we now have what we have. However, you make a good point that diseases have had 1000s of years to change and man’s adaptive immunity system has had to keep up. Our ancestors are simply behind in their studies.
(for a description of our immune system see what Google found me: http://uhaweb.hartford.edu/BUGL/immune.htm#innate)
So, someone from a different time, and I hypothesize that it could be older or newer, may very well have a hard time with diseases. Both them coming to now and now going to then.
On the other hand, go back far enough and you probably don’t have to worry about pathogens at all. Most germs are pretty specific as to what organisms they’ll infect, and before the evolution of humans, there wouldn’t be any germs evolved for us.
More likely going forward than back. Many of our infectious diseases are “new” ones not present in our ancestors by which have jumped to us from our domestic animals. And many infectious diseases can be maintained only in the dense human populations that developed after the invention of agriculture.
The earliest organisms may not have produced all the nutrients needed to sustain a human long term. Recent threads pointed out to me that vitamin B-12 is mainly produced by gut bacteria, which can’t be absorbed by humans because it is produced too far along in the digestive tract. A person could save and consume their feces to get some back, but given the generally low absorption rates in humans that may not be sufficient, not to mention that I’m guessing that feces taste like shit. There are probably a variety of other nutrients that wouldn’t be readily found in the most primitive organisms.
