Fat cultivated seeds: skinny wild seeds
July 12, 2001 - BBC
Modern farming is based on 13 millennia of experience.
Modern humans began farming centuries earlier than previously thought, a new study claims.
The transition from collecting wild grains to deliberately growing crops was one of the most dramatic changes in human history.
"This was the other great change for humanity after the mastery of fire. We began to imagine ourselves masters of the environment," explained Professor Gordon Hillman of University College London, UK.
He and his colleagues spent 27 years looking at the remains of a settlement in modern Syria and now believe that the systematic cultivation of cereal crops had already begun around 13,000 years ago, 1-2,000 years earlier than previously thought.
27-year study
Professor Hillman believes the first farmers may have been a small community of hunter-gatherers originally tempted to settle in one place by good food growing wild.
"It was all very rosy for them. It was getting warmer and wetter and they had a food base so luxuriant that they were tempted to settle. But then suddenly things reversed," he told BBC News Online.
Farming was the most dramatic development since the mastery of fire.
The weather suddenly began to get colder and drier, and the hunter-gatherers were faced with a choice: either move on and face the possible wrath of other hungry communities elsewhere or stay put and start farming.
They chose the latter, and as they did so, they changed the way that they harvested.
New technology
Instead of beating wild crops to release their grains, they began to uproot them or cut them down.
This change of approach favoured the survival of different types of crop, and within a short period, one of the things they had domesticated was what we now recognise as rye.
The change was probably not a deliberate policy on the part of the community, but rather a response to the worsening weather.
"We know from modern hunter-gatherers that they are usually reticent to make the change. Recent hunter-gatherers have resented Europeans coming to do just that, foreseeing some of the ecological damage that results," he said.
But in the end, the community prospered, reaching a strength of several thousand.
Flotation recovery
Professor Hillman and colleagues from Oxford University, UK, and Rochester Institute of Technology, US, explain their findings in the journal The Holocene.
They sifted through huge amounts of earth from the dig at Abu Hureyra to recover charred remnants of food.
"The only way this stuff survives is by being exposed to fire. Occasional scraps of food survive and we dunk the excavated earth in water. The little scraps float and we use a machine and a mesh to separate them out," he said.
The evidence from Abu Hureyra is the earliest start to farming so far found by researchers, but the group behind this latest discovery believes it will be backed up by other digs in the area, straddling the Tigris and Euphrates rivers, where the modern way of life began.
"We anticipate that equally early evidence of analogous events will eventually be recovered from other sites in the Fertile Crescent," they write.
June 18, 2001 - USA News.com
Some of the first seeds of civilization sprouted when people stopped chasing dinner and started raising it. Settlers formed villages. Landowners gained power. And a boom in leisure time eventually led to gourmet delis and Internet cafes. But who shepherded the first lamb or watered the first asparagus crop?
Such questions have long intrigued anthropologists because of a basic curiosity about humanity's major cultural transitions. But recently geneticists have become interested as well, for more practical reasons. A long-range perspective on genetic diversity, they argue, could help modern farmers avoid the perils of selective breeding and cultivate meatier livestock and more resilient crops.Much of the search for domestication's beginnings has focused on a vast region of the Middle East called the Fertile Crescent. Stretching from the Persian Gulf to southeastern Turkey and northern Egypt, the area's high mountain pastures and low-lying plains were generally hot, wet, and lush at the end of the last Ice Age, 11,000 years ago. Thick stands of barley, rye, wheat, and lentils grew wild. Cattle, sheep, goats, pigs, and gazelles roamed free.
Such conditions were ripe for people to plant their own seeds and tame their own livestock, says Yale archaeologist Frank Hole. Even so, the switch from hunting and gathering to domesticating and cultivating seems to have happened independently in scattered places around the world, according to a flurry of new analyses involving both fossils and DNA.
Goats were likely the first to give up their wild ways, according to archaeologist Melinda Zeder of the National Museum of Natural History in Washington, D.C. People don't kill their own goats the same way they kill wild ones, Zeder notes.
To maximize meat for their efforts, hunters kill the biggest animals first, while herders kill small, young males and keep females around longer to breed. In fact, Zeder found a fossil pattern in the Fertile Crescent site of Ganj Dareh, from about 10,000 years ago, that supports that theory.
Other DNA evidence indicates that after the initial domestication of goats, migrating people took the animals with them all over the world to trade as good sources of meat, milk, and wool. Other scientists have found multiple origins for cows, pigs, and yaks.
This new research suggests that modern breeders could learn some important lessons from their predecessors. For thousands of years, shepherds preserved the genetic vigor of their herds by keeping variety in the gene pool, Zeder says.
More recently, breeders have instead sacrificed such genetic diversity for profitable traits, including rapid growth, disease resistance, and higher-quality meat, milk, and fur.
Squash detective. In a similar way, research on ancient plant domestication could help improve today's crops, says Bruce Smith, an archaeobotanist with the National Museum of Natural History. He has pinpointed the origins of squash domestication to 10,000 years ago in Oaxaca, Mexico, and plans to cross wild squash with genetically modified squash to test whether genetic tinkering might threaten biodiversity.
Scientists are also on the trail of the first domesticated corn, beans, carrots, and garlic. One group recently announced dating the first domesticated maize, from a cave in Oaxaca, to about 6,300 years ago. Other work is revealing corn's genetic transformation from an unappetizing, unwieldy plant to the easily harvestable and succulent crop of modern times.
May 6, 1999 - AP - Athens, Greece
The ancient Greeks may have been baking high-quality bread long before commonly thought. That's the conclusion of two British experts who are studying what people ate in the days before recorded history and how their choice of food may have shaped the destiny of humanity.
They are delving back to when history is preserved on a molecular scrapbook rather than on stone or parchment. "We have discovered that it is possible to obtain small traces of DNA from preserved wheat seeds, some dating back to the earliest stages of agriculture," researchers Terry Brown and Glynis Jones.
The recent report, New Ways with Old Wheats, suggests that Bronze Age Greeks could have begun baking high-quality bread as early as 3300 B.C. That is centuries before experts have believed the types of wheat needed to produce bread similar to modern varieties existed. Brown, a molecular biologist at the University of Manchester Institute of Science and Technology, and Jones, an archaeobotanist at the University of Sheffield, hope to use modern DNA techniques to answer questions about such things as how farming spread, a central factor in the progress of ancient civilizations.
Bread has played a great role in the development of civilization and religion. Homer talked about it. Egyptian pyramid builders ate it. The Bible says Jesus used it to feed the multitudes. Roman Emperors pacified the masses with "bread and circuses." All that is different now is the way (bread is) manufactured. It's exactly the same product now as it was during Roman times.
In their study, Brown and Jones looked at 3,300-year-old charred wheat grains discovered in Assiros, a Bronze Age backwater in northern Greece. What they found was that the Bronze Age wheat had good bread-making qualities, something not thought possible at the time.
Bread wheat is not naturally occurring and had to be developed through crossbreeding. Before learning how to make bread, prehistoric peoples consumed wheat as meal or gruel. The findings also suggest wheat has been domesticated twice and in two different places, rather than only once as was previously believed, the two experts said. Wheat was thought to have first been domesticated about 8,000 B.C. in the Fertile Crescent, an area that crosses parts of modern day Iraq, Iran and Jordan. But a parallel development appears to have been going on in northern Greece.
The findings could alter the way historians render the timeline and location of ancient farming methods and technology.
Another discovery in the ancient wheat were DNA markers suggesting a husked variety known as spelt, which experts previously did not think had become known in the Mediterranean area until the 1st century of the Christian era. Husked wheat, which produces bread similar to modern "stone-ground" varieties, contains a hard covering that is commonly broken off with a stone grinder.
"Spelt's been around a long time," said Brian Park, a consultant with Britain's Allied Mills. "It's a very old variety still milled in Germany and Holland. It is perceived to be healthier. The ancient spelt would have made a "squat, small loaf with a close crumb structure." His company is milling spelt on millstones and are looking to market it as a health food product. Stone ground, just like in those ancient days.
There also has been an unexpected contemporary "spin-off" from the DNA research, Brown said. Because it is sometimes difficult to differentiate between some types of ground or processed wheat, the DNA technique now will let millers test a grain shipment's molecular and genetic makeup. This will allow them, for example, to determine whether more expensive durum wheat used to make pasta has been adulterated with cheaper bread wheat.
March 1999 - BBC
One of the earliest experiments in genetic engineering took place about 7,500 years ago and resulted in the first corn on the cob. Scientists have retraced steps taken by Stone Age farmers who created the first maize crop from a Mexican wild grass using a sophisticated process of genetic selection.
A study into the genetic ancestry of the maize plant found it is derived from a nondescript species of wild grass which grows in Mexico. The researchers have found how Neolithic farmers in North America selected specific strains of the wild grass which eventually resulted in a plant that produced a tightly knotted clump of nutritious seeds on a cob. The study found the farmers were unwittingly modifying a genetic-control region in the grass which caused long tassels of its seeds to shorten into edible ears that could be harvested more easily.
John Doebley, who led the research team at the University of Minnesota, said the study confirmed how the maize plant, which does not exist naturally, was derived artificially by a process of genetic selection from a wild Mexican grass called Balsas teosinte. The artificial selection carried out by the early farmers increased the total amount of variation seen in modern maize crops, which are far more diverse than the ancestral grass from which the were derived, the researchers report in Nature.
"Our results help to explain why maize is such a variable crop. They also suggest that maize domestication required hundreds of years, and confirm previous evidence that maize was domesticated from Balsas teosinte of south-western Mexico," they report.
Svante Paabo, an expert on archaeological genetics at the Max Planck Institute in Leipzig, said the research is important because it demonstrates how quickly domestic crops were produced from wild plants. "This is a significant result because archaeologists are still debating how many centuries or millennia were necessary for early farmers to achieve the changes that made maize a mainstay of farming," Dr Paabo said.
"Of all human inventions, none has had a more profound effect on our history - and on our biosphere as a whole - than agriculture. This momentous development relied on the genetic manipulation of only a handful of plants by early farmers."
Wild Mexican grass looks so different from domesticated maize that their close relationship could only be confirmed by the genetic analysis that showed how the long tassels became short ears.
"This study is fascinating to me because it provides the first glimpse of what went on during one of the earliest genetic-engineering experiments," Dr Paabo said.
The genetic techniques used in the study could also be used to dissect the modification that took place to create other domestic plants and animals, including cats and dogs, he added.
September 25, 1999 - Discovery Channel Online News
Who was the first to develop sophisticated farming methods? The Babylonians? The Mayans? The Chinese? No, no and no. Try ants. Some kinds of ants have been systematically growing mushrooms in their nests for 50 million years, according to researchers. They weed, fertilize and even secrete "herbicides" to combat pests.
Using genetic techniques, ant expert Ulrich Mueller of the University of Maryland and his colleagues traced the lineage of mushrooms cultivated by ants in Florida, Panama, Costa Rica, Trinidad, Guyana and Brazil. Then Mueller compared the lineage of these 'shrooms to those of their wild counterparts.
Mueller found that the ants in these areas are cultivating five very different strains of fungi between them, suggesting that at some point long ago each of these mushrooms may have been "domesticated" by different colonies of ants independently of each other.
He and colleagues report their findings in the latest issue of the journal Science. Previously, many scientists theorized that ant farming started with one community and then spread each time a young queen, bringing some fungus with her, started a new colony or nest. Mueller suspects that ant farming also spread by distantly related ants sharing their fungus.
Mueller's research showed that distantly related ant species sometimes cultivate the same strain of mushroom. On the other hand, some species cultivate up to eight different mushroom strains. In fact, one ant species introduced into Florida earlier this century has already started cultivating a strain, or "cultivar," originally farmed by an indigenous species of ant. "This would imply that cultivars are passed on between ant species quite frequently," Mueller says.
Mueller next wants to see if ants' preferences in mushroom flavors and smells have affected mushroom characteristics.
To physiologist Jared Diamond at the UCLA Medical School, Mueller's approach suggests another idea. He points out that in addition to growing crops and animals, human farmers have accidentally "domesticated" the pathogens like measles and smallpox, since they are mutations of pathogens in farmyard animals.
If one were to track the genetic legacy of these diseases in the same way Mueller tracked the genetic legacy of the mushrooms, what might it reveal, Diamond asks "about the likely time and place of origin of these diseases that played so large a role in human history?"
March 12, 1998 - Reuters
Archaeologists discovered a prehistoric village that boosts the theory that people may have put down roots and farmed land in North America much earlier than first thought. A study in the journal Science reports that groups of people settled a large riverside parcel in extreme northwestern Mexico 3,000 years ago. They built a 25-acre village and practiced a primitive form of agriculture, probably using sticks to prepare the earth for growing plants such as squash and corn.
The finding is significant because until now archaeologists have believed the inhabitants of the region were hunter-gatherers who did not stay in one place very long -- at least until they established relatively permanent agriculture-based communities 1,000 to 1,500 years ago.
"Most of the sites that we've known the past 50 years have been small camps," said Robert Hard of the University of Texas at San Antonio, who worked on the study. "This site is so much greater in scale. It appears there were more people living in a village than we imagined and they were more sedentary than we imagined."
The findings bolster other research suggesting ancient cultures built and grew things in North America long before anyone thought. A study in Science last September described a series of permanent mounds built by people living 5,400 years ago in what is now Louisiana.
But Hard and his colleague, John Roney of the U.S. Bureau of Land Management, said the significance of their research lies in the location, size and development of their site 150 miles southwest of El Paso, Texas, as well as evidence that it might have been an agricultural settlement of some permanence.
The site in Chihuahua on the banks of the Rio Casas Grandes involved construction of berms and 500 arc-shaped terraces. Roney would not guess the village population, butsaid it probably involved "many families." He said it probably took at least 16 years to build the village, but more research is needed to determine how long it was occupied and to find out the true extent of agricultural activities
Fat cultivated seeds: skinny wild seeds
October 28, 1999 - BBC Online
The first farmers grew wheat and rye 13,000 years ago in Syria and were forced into cultivating crops by a terrible drought, according to UK archaeologists.
Professor Gordon Hillman, at University College London, has spent over 20 years investigating the remains of ancient food plants at a unique site at Abu Hureyra, in the middle Euphrates.
"Nowhere else has an unbroken sequence of archaeological evidence stretching from hunter-gatherer times to full-blown farming," he told BBC News Online.
Hunter-gatherers
The evidence for cultivated crops comes from seeds carefully sifted from the material excavated at Abu Hureyra. These had survived because they had been accidentally charred in domestic fires before eventually becoming buried.
Many years of ecological field work assessing present day vegetation was also necessary to provide a basis for interpreting the material found.
"What we expected to find from the hunter-gatherer levels at the site was lots of wild cereals. These are characteristically very skinny and we found plenty of them," explains Professor Hillman. "But then, at higher and later levels, we found things that did not belong there. There were these whacking, great fat seeds, characteristic of cultivation."
The cultivated seeds found at Abu Hureyra are the oldest yet found.
A dry death
Professor Hillman and his team found that, as they looked through the archaeological record, the wild seed varieties gathered as food gradually vanished, before the cultivated varieties appeared. Those wild seeds most dependent on water were the first to die out, followed one by one by the more hardy ones.
This was a clue to why the hunter-gatherer people turned to cultivating some of the foods they had previously collected from the wild, and prompted Professor Hillman to look at independent climate records for the period.
What he found was evidence for a terrible drought: "It was very sharp and would certainly have been felt within a human lifetime, perhaps even in the space of 10 or so years."
Geologist call this period the Younger Dryas, a 1000-year spell of cold and dry weather with interrupted the planet's gradual warming from the last ice age.
Professor Hillman's team suggest that as the wild grasses and seeds that the people relied on for food died out, they were forced to start cultivating the most easily-grown of them in order to survive.
Professor David Harris, also at UCL, said: "There came a point when this community had no option - they were stuck with agriculture." The archaeologists found no evidence that the irrigation was used to grow the first crops as the drought set it. Professor Hillman explains: "What they did was to take seed of the wild cereals from higher areas to the West, and sowed it close to Abu Hureyra in areas such as breaks in slope, where soil moisture was greatly enhanced naturally."
"Wild stands of these cereals could not have continued to grow unaided in such locations because they would have been out-competed by dryland scrub. Therefore, these first cultivators had to clear the competing vegetation."
CRYSTALINKS MAILING LIST, NEWSLETTER, UPDATES