Why did hunter-gatherers first begin farming?

May 16, 2017
Credit: CC0 Public Domain

The beginnings of agriculture changed human history and has fascinated scientists for centuries.

Researchers from the Grantham Centre for Sustainable Futures at the University of Sheffield have shed light on how hunter-gatherers first began farming and how were domesticated to depend on humans.

Domesticated crops have been transformed almost beyond recognition in comparison with their wild relatives - a change that happened during the early stages of farming in the Stone Age.

For grain crops like cereals, the hallmark of domestication is the loss of natural dispersal - seeds no longer fall off plants but have become dependent on humans or machines to spread them.

Professor Colin Osborne, from the Grantham Centre for Sustainable Futures at the University of Sheffield, said: "We know very little about how agriculture began, because it happened 10,000 years ago - that's why a number of mysteries are unresolved. For example why hunter-gatherers first began farming, and how were crops domesticated to depend on people.

"One controversy in this area is about the extent to which ancient peoples knew they were domesticating crops. Did they know they were breeding domestication characteristics into crops, or did these characteristics just evolve as the first farmers sowed wild plants into cultivated soil, and tended and harvested them?"

The new research, published in the journal Evolution Letters, shows the impact of domestication on vegetable seed size.

Any selective breeding of vegetables by early farmers would have acted on the leaves, stems or roots that were eaten as food, but should not have directly affected seed size.

Instead, any changes in vegetable seed size must have arisen from natural selection acting on these crops in cultivated fields, or from genetic links to changes in another characteristic like plant or organ size. In the last instance, people might have bred crops to become bigger, and larger seeds would have come along unintentionally.

The University of Sheffield researchers gathered seed size data from a range of crops and found strong evidence for a general enlargement of seeds due to domestication.

They discovered domesticated maize seeds are 15 times bigger than the wild form, soybean seeds are seven times bigger. Wheat, barley and other had more modest increases in size (60 per cent for barley and 15 per cent for emmer wheat) but these changes are important if they translate into yield.

"We found strong evidence for a general enlargement of seeds due to domestication across seven vegetable species," said Professor Osborne.

"This is especially stunning in a crop like a sweet potato, where people don't even plant seeds, let alone harvest them. The size of this domestication effect falls completely within the range seen in cereals and pulse grains like lentils and beans, raising the possibility that at least part of the seed enlargement in these crops also evolved during without deliberate foresight from early farmers."

Professor Osborne added: "Our findings have important implications for understanding how crops evolved, because they mean that major changes in our could have arisen without deliberate foresight by .

"This means that unconscious selection was probably more important in the genesis of our food plants than previously realised. Early increases in the yields of crops might well have evolved in farmers' fields rather than being bred artificially."

Explore further: Weedy rice, which differs genetically from wild and crop rice, is adapted for undercover life in agricultural fields

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someone11235813
5 / 5 (1) May 16, 2017
Seeing as agriculture developed independently in many areas, there is likely slight variations in how it began. But it's pretty clear that it could not have begun with deliberate breeding because the concept would not be known. It would first have to be observed.
dogbert
5 / 5 (1) May 16, 2017
I'm surprised with the viewpoint that domestication changes were spontaneous rather than planned. Certainly, we may expect that some changes were spontaneous, but the very rapid transition to forms better suited for harvest strongly implies deliberate selection for desirable traits.
Iochroma
5 / 5 (4) May 16, 2017
beer.
It has been stated here and elsewhere that the ability to make fermented alcoholic products from grain was very likely to be the motivator that made people settle in areas conducive to grain growing. It allowed for organized social networks to grow, harvest, and store the ingredients to make beer. The fact that grain could also be eaten directly was probably secondary.
michael_frishberg
not rated yet May 16, 2017
Why did they first farm? Because they had too many children, as hunter/gatherers, for women to carry, the women went on strike, "figure out a way we can stay in one place", and men owned farming, after many generations of horticulture had already staged the means for a more aggressive approach to feeding one's family.
Farms needs cities.
EVEN THOUGH, cities had higher disease rates (proximity and lack of sewerage/sanitation), they were still built...
ZergSurfer
3.7 / 5 (3) May 16, 2017
"beer." Upvoted for that sentiment. I wonder if it's (fermentation) something we picked up from over ripe fruit and took out of africa.
http://news.berke...r-booze/
rrwillsj
3 / 5 (4) May 17, 2017
Problem with this type of research is the researcher's lack of experience feeding a family. Have they ever worked a scratch farm or even gardening? Raised animals or ever had to hunt & fish to feed themselves?

Everywhere was a virgin wilderness. i.e. damn little to eat at the best of times and what there was, wasn't all that edible. Hunting was exhausting and dangerous. Prey were not cooperative and predators didn't want to share.

The women and children foraging for anything edible. Baking plants in campfires made them easier to digest. And what didn't digest was crapped out near the camp.

Always on the move, the hunter-gathers reused the better campsites. To find previously selected clumps of edibles growing from the firepits and latrines of their predecessors. This cycle repeating for thousands of years. Slowly accumulating in fertile areas an increasingly better selection of food plants. Which attracted prey to be selected for domestication.
PTTG
not rated yet May 18, 2017
@rrwillsj, your comment has nothing to do with the content of the article. It's like you just read the headline and imagined a study done by a millennial scientist in need of your homey wisdom.
rrwillsj
May 18, 2017
This comment has been removed by a moderator.
Whydening Gyre
5 / 5 (1) May 18, 2017
Problem with this type of research is the researcher's lack of experience feeding a family. ...

Reference cite?
FredJose
1 / 5 (2) May 26, 2017
Mmmmhhhh, let me see: Kain was the farmer and Abel did the shepherding trick. There were no hunter-gatherers at the time the first agriculture took place. That kind of living only started after the global flood and even then only after the dispersal at Babel took away common knowledge, leaving some to resort to hunting for survival.

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