Because for individuals making rational decisions, tending to crops and livestock is easier than hunting and gathering, and it won't necessarily be obvious over the timescale of a lifeapan that such a lifestyle is detrimental to health, especially if you're talking about a pre-scientific, pre-literate society with no real form of record keeping.
Plus, the shift is going to be gradual - you start by supplementing with a small garden, a handful of captive prey animals during hard times, then after some number of generations you come to rely more and more on agriculture without necessarily realizing why or even if your tribe is showing minor signs of mysterious illness. And then if you do realize that something is up, you're probably cursing the earth/gods/demons for your illnesses, rather than coming to understand the true variety required in a healthy diet and abandoning the convenience of your farming practices, which are in no way an obvious problem.
Tending crops is not easier than hunting. Especially in the early Neolithic when bronze hasn't even been discovered yet. But even today, farming is tougher than hunting. The difference is that farming and animal husbandry scales tremendously well. Predators regularly die off in the prey-predator cycle. Agriculture when done right and under favorable climates is predictable and scalable.
Pick between spearing a bison or gazelle with a rock tip, or harvesting from a small plot of not quite domesticated, hardy crop that you just scattered somewhere fertile, and putting off the hunt for a few more days. Or a proto-goat you keep tied up somewhere where it can graze.
It's a gradual process and has immediate benefits even on a small scale with relatively low investment. Consider also that women were probably not hunting, and probably had some spare time when they weren't gathering/taking care of kids or what have you. It's pretty easy for a community of Hunter gatherers to have occasional free time, if you look at data from more recent tribes from the last hundred years or so. Plus there's all kinds of art and such...simple crop rearing and basic animal raising isn't hard to imagine.
A Bison will feed a whole tribe for a month. You can only harvest most crops once a year. Veggies don't bloom all the time. By 10K years ago, humans had already invented the bow and arrow. They also had other clever techniques. Definitely worth the risk. The modern crops we eat today didn't even exist in the wild. It took thousands of years of selective breeding to get modern vegetables and tubers. Throwing seeds is NOT enough to grow real crops in any amount that will actually feed anyone, especially the kind of crops that were around 10K years ago. Farming takes a fuck ton of work. You have to water them, you have to fertilize them, you have to defend them from other animals, you have to weed out other plants competing with it for resources. It's not a simple thing. It's back breaking labor. There's a reason why 90+% of the population were farmers until the invention of gas engines, automated harvesters, electricity, etc.
>Throwing seeds is NOT enough to grow real crops in any amount that will actually feed anyone, especially the kind of crops that were around 10K years ago.
Yes, that was one of my points. The initially farmed plants were fully wild and hardy enough that they probably could be grown just by scattering seeds around.
>Farming takes a fuck ton of work. You have to water them, you have to fertilize them, you have to defend them from other animals, you have to weed out other plants competing with it for resources. It's not a simple thing. It's back breaking labor. There's a reason why 90+% of the population were farmers until the invention of gas engines, automated harvesters, electricity, etc.
Again, we're not talking modern, large scale optimized farming of GMO crops that would not survive without human care. We're talking about small, gradually expanding plots of almost wild, and therefore low maintenance, supplemental crops, that over generations become a larger and larger part of diet. How else do you think farming started?
A bison will feed a whole tribe for a month, sure, but it can also take tribe members with it, especially with your stone tipped, non compound bows. If you happen across an unusually supportive yield of whatever semi wild tubers you planted and basically forgot about, there's no reason a human wouldn't put off a dangerous hunt.
Anyway, the original question was why Hunter gatherers started farming if it were bad for them. I'm trying to show how it's possible for that to have happened. I'm not sure what you're arguing, that farming could not have occurred in any beneficial capacity before combines? Have you ever had a vegetable garden? Hardly backbreaking work if you're lucky enough to have good soil and the right climate for whatever you're growing...
Again, this is a gradual process. Hell, I can think of a modern analogue that I've picked myself, the blue Camas plant that grows all over the PNW in patches. It doesn't take much work once you've figured out you can plant them yourself next to your cave/camp.
Well I agree with you on the point of crops starting as supplements and then gradually becoming a more significant part of the diet and especially after the climate shifted from the last glacial period to the early Holocene warmth.
Even just 3-6 adult human men with spears is a force to be reckoned with in the animal kingdom. They're capable of strategizing, trapping, corralling, etc. Also, animals weren't just used for food in the stone age, the bones were used for structures, tools, etc. The leather was used for clothing, warmth, huts, etc. Humans certainly continued to hunt in the early days of agriculture.
It probably was the case that other humans less capable of hunting due to higher risk and lower strength (elderly, women, children, injured, etc) gathered and tended crops to contribute to the tribe.
Like you say, agriculture gradually got more and more efficient. Better tools, better breeding, etc, and the tribes that grew crops and raised animals were able to feed more people than the ones that hunted and gathered alone. This intensified after the bronze age.
Agriculture is beneficial because it causes abundance and predictability, even if it is more work on average. It's a ton of work to produce even 430,000 kCal of veggies (the amount found in a single modern cow), especially with early breeds of potatoes (which were tiny). I would wager that if you did the energy spent vs energy acquired calculation that hunting comes out way ahead of farming.
With farming you have to plan ahead for months at a time. The difference is that agriculture manifests abundant energy for consumption that would otherwise not exist. That's a huge evolutionary advantage, and obviously the entire reason we're able to have this discussion hundreds of miles apart from each other at instantaneous speed.
Plus, the shift is going to be gradual - you start by supplementing with a small garden, a handful of captive prey animals during hard times, then after some number of generations you come to rely more and more on agriculture without necessarily realizing why or even if your tribe is showing minor signs of mysterious illness. And then if you do realize that something is up, you're probably cursing the earth/gods/demons for your illnesses, rather than coming to understand the true variety required in a healthy diet and abandoning the convenience of your farming practices, which are in no way an obvious problem.