How Did Cavemen Realise They Need To Eat In Order To Survive

What was the first thing you think the cavemen figured out to survive, thousands of years ago?

There is no simple answer to this question, unless you are prepared to study archaeology.Firstly the name “cavemen” is a populist misnomer - although a few communities appear to have lived in, or at least had their home-bases in, caves, since caves are in relatively short supply, most of our ancestors had to find some sort of shelter - either from the sun or from wild beasts, so shelter building was probably one of the earlier skills that had to be learnt.Secondly, foraging or scavenging for food was probably learned quite early on in human evolution - namely what was good/nutritious to eat, when it was obtainable and where, so that has to be a given. But one early skill was probably that of scavenging the remains of the kills of carnivores and learning how to crack open bones to access the high-energy marrow, and so simple stone tools were probably the next to be developed. At first these would have simply been naturally-shaped rocks (much as those used by capuchin monkeys & chimpanzees), used as hammers, but when flint’s unusual properties were discovered, then flint-knapping became a craft, an art and more and more uses for this early technology were discovered.Thirdly, how to tame and make fire. It is likely that lightning-strikes were the first sources of fire, then humans realised that if they did not move too close to the flames that they would not be burnt, but that other animals kept away. It was probably a happy discovery that cooking came about - food that had been carefully burnt tasted better and required less chewing. Learning how to make fire probably took much, much longer, so it is likely that ways to carry coals were probably developed first.Fourthly, clothing technology would have first been used by those humans who ventured into Eurasia - in the grip of an Ice Age. There is an interesting echo of this discovery in the biblical book of Genesis: “And the eyes of both of them were opened, and they knew that they were naked. And they sewed leaves of the fig tree, and made girdles for themselves.” (Gen 3:7 LITV)… “And YHWH God made coats of skin for the man and his wife, and clothed them.” (Gen 3:21 LITV)This seems to imply that Eden was a warm, even a hot location, but that oral traditions remembered the move to colder climes, where animal skins had to be used. (Curious that the Bible does not mention God’s prowess as a hunter - after all, are we to understand that God happened to have the animal skins just lying about?!)

How did humans find out they needed salt?

Since all animals need a certain amount of salt in their diet to replace what is lost through urination, it wasn't so much as we figured out at some point that we needed salt because we always needed it and always sought it out.  Humans are fairly unique in that we are hairless and we sweat a lot, thus needing even more salt than other animals. However, this happened slowly over millions of years, giving us plenty of time to figure out how to get the larger amounts we need.  In terms of knowing we need it, that is simple, like water and food and sex, we simply crave it, always have.  When we don't get enough we crave it more and eventually will become ill without it.  The common theory of our evolution, particularily our loss of hair and propensity to sweat, was that it occurred in south Africa along the coast, in conjunction with the discovery of seafood.  We could wade out into the water and catch it or pry it off the rocks fairly easily.  Seafood was extremely high in protein and is excellent for brain development.  A little seawater provides all the salt you need.  Figuring out how to dry sea water to make dry salt wasn't too difficult and later, we even discovered salt deposits in the ground.  Salt was likely one of the first commonly traded goods, especially with our inland relatives who needed it in dry form, being too far away from the sea.  It was probably our very first currency, being extremely valuable and having a fairly consistent need everywhere.  Once consumed, you had to get more.  Seashells used for jewelry came along for the ride.

How did prehistoric humans meet their daily salt needs?

Paradoxically, the advent of agriculture actually increased the likelihood of sodium deficiency.  Prehistoric humans ate a significant amount of red meat.  Large herbivores (which early man would have hunted) tend to eat much more vegetable matter than any human could muster, so the trace amounts of sodium in most grasses and plants per volume was sufficient for them.  The animals would pass this sodium onto the humans who ate their flesh.  As mentioned in the aforementioned book by Kurlansky, agrarian societies were much more likely to engage in the salt trade than those who that consumed more meat.  People didn't realize how much they like salt until it became less abundant in their eating habits.While not a perfectly scientific comparison, this site notes that three ounces of unprocessed venison (a fraction of what paleolithic humans ate in a day) contains 77 milligrams of sodium--as noted by Mickael, this is more than what is  necessary for the average person per day.http://www.alsosalt.com/socounfo...

Why did humans start to eat meat?

Our original “natural” diet contained a lot of meat and fish.Hunter gatherers don’t practice farming. And before farming the number of plants available was very low. And these plants lacked a lot of proteins.The Earth was not a kitchen garden!We can’t digest most of the plants, because we can’t digest cellulose. We need very specific plants. And the plants we are eating today are the result of centuries of selection and engineering.Have you seen at what corn looked like before human selection?Wild eggplant looked like that before thousand years of human selection:Primitive versions used to have spines on the place where the plant's stem connects to the flowers. https://www.hort.purdue.edu/newc...Today wheat has an abnormally high protein content, result of the selection of several mutations. Same thing for soy and rice. But in the nature, these plants are not enough for living.No primitive human could have survived on a vegan diet.By the way, before the invention of advanced techniques (pottery, housing, fruits drying, fermentation) we were unable to store food for a long time.Fruits are here only for a few months a year. Corn and wheat don’t grow during the winter.There is no known tribe of primitive humans living only with plants without farming techniques.Humans can’t be vegan if they are not able to farm.Today humans can be vegan because they are able to farm and to store food efficiently. Because they have breed super-optimized crops. Because they have advanced knowledge on nutrition. But it is not natural at all, and it was impossible in the past.All primitive pre-farming humans were hunter gatherers (with the vast majority of their food coming from hunt and fishing).For reference, chimpanzee and baboons eat meat.