What is the significance of the domestication of wheat?
The domestication of wheat was instrumental in the transition of human behavior from hunter-gatherers to farmers. It was a key event in the agricultural revolution that occurred about 10,000 years ago in the Fertile Crescent of the Middle East.
When did wheat become domesticated in the Levant?
The evidence is abundant that by about 10,400 years ago, domesticated wheat was in widespread use throughout the Levant region; but when that started is up for debate.
How did wheat become the staple crop of early farmers?
These early domesticates were staple crops of early farmers for several thousand years before being replaced by free-threshing wheats. Allopolyploidization, mutations in genes governing threshability and other domestication related traits, and interspecific gene flow led to the formation of today’s economically important bread wheat.
How and why did the agricultural revolution begin?
With new technology come new and ever-evolving theories about how and why the agricultural revolution began. Regardless of how and why humans began to move away from hunting and foraging, they continued to become more settled. This was in part due to their increasing domestication of plants.
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Why was the domestication of wheat important?
The domestication of wheat around 10,000 years ago marked a dramatic turn in the development and evolution of human civilization, as it enabled the transition from a hunter-gatherer and nomadic pastoral society to a more sedentary agrarian one.
How was wheat domesticated?
One possible way that might have occurred is that farmers harvested wheat after it was ripe, but before it self-dispersed, thereby collecting only the wheat that was still attached to the plant. By planting those seeds the next season, the farmers were perpetuating plants that had later-breaking rachises.
Did we domesticate wheat or did wheat domesticate us?
This completely changed their way of life. We did not domesticate wheat. It domesticated us. The word “domesticate” comes from the Latin domus, which means “house.” Who’s the one living in a house?
When did humans first domesticate wheat?
about 10,500 yearsThe earliest definitive traces of domesticated grains, wheat, barley, and oats have been found in the Near East and date back about 10,500 years.
In which reason was the wheat First grown?
Genetic analysis of wild einkorn wheat suggests that it was first grown in the Karacadaǧ Mountains in southeastern Turkey. Dated archeological remains of einkorn wheat in settlement sites near this region, including those at Abu Hureyra in Syria, suggest the domestication of einkorn near the Karacadag Mountain Range.
Was wheat the first domesticated crop?
Einkorn wheat The crop is among the first eight crops to be domesticated and cultivated.
What does Harari mean when he suggests that wheat domesticated humans?
The fraudsters, in Harari’s telling, were wheat, rice, potatoes and a few other plants, who “domesticated Homo sapiens, rather than vice versa.” That is, by allowing themselves to be domesticated, which many other plants refused to do, these plants tricked human beings into spreading their genes, turning the plants …
What is wheat used for?
Wheat, used for white bread, pastries, pasta, and pizza, has been the principal cereal crop since the 18th century. Wheat was introduced by the first English colonists and quickly became the main cash crop of farmers who sold it to urban populations and exporters.
What is the history of wheat?
The cultivation of wheat was started some 10,000 years ago, with its origin being traced back to southeast Turkey. It was called Einkorn (Triticum monococcum) and genetically is described as a diploid, containing two sets of chromosomes. At a similar time, Emmer wheat (Triticum dicoccum) was being domesticated.
What is the relationship between wheat and its early hearth of domestication?
Which of the following correctly explains the relationship between wheat and its early hearth of domestication? Wheat was first domesticated in Mesopotamia because of a favorable climate and a great diversity of wild grains that led to crossbreeding of seeds.
What is the economic importance of wheat?
Various studies and researches show that wheat and wheat flour play an increasingly important role in the management of Indias food economy. Wheat production is about 70 million tonnes per year in India and counts for approximately 12 per cent of world production.
How did we domesticate crops?
People collected and planted the seeds of wild plants. They made sure the plants had as much water as they needed to grow, and planted them in areas with the right amount of sun. Weeks or months later, when the plants blossomed, people harvested the food crops.
Why is wheat adapted to the wild?
The wild relatives of wheat and barley are adapted to prevent flowering from occurring when conditions are unsuitable for floral development. In wild relatives of wheat and barley, as well as in unvernalized winter varieties, vrn1 genes are expressed at low levels, whereas in spring varieties Vrn1 is constitutively expressed. A prolonged period of cold increases expression of vrn1, eventually leading to promotion of the development of reproductive tissue (Trevaskis et al. 2003; Yan et al. 2003 ).
What two crops were the founders of the agricultural revolution?
Abstract. Wheat and barley are two of the founder crops of the agricultural revolution that took place 10,000 years ago in the Fertile Crescent and both crops remain among the world’s most important crops.
How is the wheat genome different from the barley genome?
The barley genome is smaller (∼5 Gbp) but is also complex and repetitive. Complexity reduction techniques, such as exome capture or genotyping-by-sequencing, have been used to capture variation for these two crops. Jordan et al. ( 2015) used exome capture and genotyping-by-sequencing to study the genetic diversity of 62 bread wheat lines. In addition to describing allele frequency and distribution of SNPs and indels, they found that advantageous mutations at a single homoeologous region was often sufficient to confer a fitness benefit. Later, Russell et al. ( 2016) re-sequenced 267 wild barley and landrace accessions. Their primary conclusion was that variation is related to environmental adaptation.
What are the differences between domesticated and wild plants?
These differences, including non-dehiscent spikes, free-threshing grain, reduced seed dormancy and altered flowering time are key to domestication because they control traits that facilitate human collection and consumption, which would otherwise be deleterious in nature. These traits may be considered as domestication traits or crop evolution under domestication traits. The difference between the two terms depends on whether there is a clear dimorphism between wild and domesticated plants, such as shattering in cereals, or whether variation exists between both groups.
Why are roots important to plants?
Unlike the above ground part of plants, the root system is not well studied; nevertheless, the roots are equally important to the plant for anchoring the plant and nutrient uptake (Osmont et al. 2007 ). One study, in particular, elegantly demonstrated that the number of seminal roots increased from three to five as a result of wheat domestication (Golan et al. 2018 ). These authors showed that, in wild wheat, two root primordia are suppressed at the embryonic stage as an adaptive purpose, allowing the plants to respond to drought at early growth stages.
What is the graphical representation of barley evolution and domestication?
A graphical representation of barley evolution and domestication Wild barley is shown on the left, two-rowed domesticated barley in the middle and six-rowed domesticated barley on the right. (Artwork credit: Mona Schreiber).
Where did cereals originate?
The Fertile Crescent is widely accepted to be the center of origin of our cereal crops (Zohary et al. 2012 ), but this is a wide region and the exact location (s) of domestication has been subject to intense debate. Figure 4 shows the location of key sites and will be discussed in depth in this section. Archaeobotanical evidence and AFLP data have established the Karacadag mountains of southeast Turkey as the likely site of einkorn wheat domestication (Heun et al. 1997; Heun et al. 2008 ). Özkan et al. ( 2002) also used the AFLP approach to show that domesticated tetraploid (emmer and later durum) wheat were likely domesticated in southeast Turkey. These authors note that several other crops (pea, chickpea and lentils) were domesticated in this region with barley, which was potentially domesticated once in the Jordan valley, being a major exception. The existence of two mutant alleles of the Btr genes supports this region, since one of them originated in the southern Levant, which encompasses the Jordan valley (Badr et al. 2000 ).
How long did it take for wheat to be domesticated?
Some scholars argue for a fairly rapid process, of a few centuries; while others argue that the process from cultivation to domestication took up to 5,000 years. The evidence is abundant that by about 10,400 years ago, domesticated wheat was in widespread use throughout the Levant region; but when that started is up for debate.
When was wheat first domesticated?
Wheat is a grain crop with some 25,000 different cultivars in the world today. It was domesticated at least 12,000 years ago , created from a still-living ancestor plant known as emmer.
What is the most common wheat?
Most of the 25,000 different forms of modern wheat are varieties of two broad groups, called common wheat and durum wheat . Common or bread wheat Triticum aestivum accounts for some 95 percent of all the consumed wheat in the world today; the other five percent is made up of durum or hard wheat T. turgidum ssp. durum, used in pasta and semolina products.
Where was Einkorn wheat first found?
The earliest evidence for both domesticated einkorn and emmer wheat found to date was at the Syrian site of Abu Hureyra, in occupation layers dated to the Late Epi-paleolithic period, the beginning of the Younger Dryas, ca 13,000–12,000 cal BP; some scholars have argued, however, that the evidence does not show deliberate cultivation at this time, although it does indicate a broadening of the diet base to include a reliance on wild grains including the wheat.
What is the culture of wheat?
The culture generally associated with the introduction of wheat and other crops from Asia to Europe is generally the Lindearbandkeramik (LBK) culture , which may have been made up of part immigrant farmers and part local hunter-gatherers adapting new technologies. LBK is typically dated in Europe between 5400–4900 BCE.
What are the differences between wild wheat and domesticated wheat?
The main differences between the wild forms and domesticated wheat are that domesticated forms have larger seeds with hulls and a non-shattering rachis. When wild wheat is ripe, the rachis—the stem that keeps the wheat shafts together—shatters so that the seeds can disperse themselves.
What traits were selected for wheat?
Other traits apparently selected for include spike size, growing season, plant height, and grain size.
How did wheat become domesticated?
The domestication of wheat was instrumental in the transition of human behavior from hunter-gatherers to farmers. It was a key event in the agricultural revolution that occurred about 10,000 years ago in the Fertile Crescent of the Middle East. Transitions of forms with natural seed dispersal mechanisms to forms with non-brittle rachises led to the domestication of diploid einkorn and tetraploid emmer wheat in southeast Turkey. These early domesticates were staple crops of early farmers for several thousand years before being replaced by free-threshing wheats. Allopolyploidization, mutations in genes governing threshability and other domestication related traits, and interspecific gene flow led to the formation of today’s economically important bread wheat. Genetics, genomics, and archaeobotany have together provided strong evidence and insights regarding the time, place, and events involved in the evolution and domestication of modern wheat, but numerous questions remain unanswered. Here, I review historical and recent findings that have shaped our current understanding of wheat domestication. Whole-genome sequence analysis, additional genetic studies, and advances in archaeology will likely address our unanswered questions in the future. A thorough and comprehensive understanding of wheat evolution and domestication will provide critical knowledge to the spawning of a new agricultural revolution, which will be necessary to provide sustenance for a rapidly increasing world population under global climate change.
Where did emmer wheat originate?
Ozkan H, Brandolini A, Schafer-Pregl R, Salamini F (2002) AFLP analysis of a collection of tetraploid wheats indicates the origin of emmer and hard wheat domestication in Southeast Turkey. Mol Biol Evol 19:1797–1801 PubMed CrossRef Google Scholar
How does agriculture affect the environment?
Agriculture alters both the animals and plants it domesticates. Ultimately, it changes the very landscape itself. The growing of a single crop in a field by definition substitutes a biological monoculture for the complex ecological system that existed on the same ground previously. This change has several effects.
What are the unintended effects of crop growing?
Unwittingly, they are also “selecting for” any organism that can live on wheat: wheat-eating “vermin,” pathogens, and diseases of wheat, etc.
Can growing crops deplete soil?
Over a relatively short period of time, growing a single crop can deplete even very rich soil. This was a problem which rendered many early agricultural sites uninhabitable after a time. It is still a very serious problem. There are other unintended effects of crop-growing.
How did wheat become domesticated?
The domestication of wheat was instrumental in the transition of human behavior from hunter-gatherers to farmers. It was a key event in the agricultural revolution that occurred about 10,000 years ago in the Fertile Crescent of the Middle East. Transitions of forms with natural seed dispersal mechanisms to forms with non-brittle rachises led to the domestication of diploid einkorn and tetraploid emmer wheat in southeast Turkey. These early domesticates were staple crops of early farmers for several thousand years before being replaced by free-threshing wheats. Allopolyploidization, mutations in genes governing threshability and other domestication related traits, and interspecific gene flow led to the formation of today’s economically important bread wheat. Genetics, genomics, and archaeobotany have together provided strong evidence and insights regarding the time, place, and events involved in the evolution and domestication of modern wheat, but numerous questions remain unanswered. Here, I review historical and recent findings that have shaped our current understanding of wheat domestication. Whole-genome sequence analysis, additional genetic studies, and advances in archaeology will likely address our unanswered questions in the future. A thorough and comprehensive understanding of wheat evolution and domestication will provide critical knowledge to the spawning of a new agricultural revolution, which will be necessary to provide sustenance for a rapidly increasing world population under global climate change.
How did bread wheat evolve?
Bread wheat expanded its habitat from a core area of the Fertile Crescent to global environments within ~10,000 years. The genetic mechanisms of this remarkable evolutionary success are not well understood. By whole-genome sequencing of populations from 25 subspecies within the genera Triticum and Aegilops, we identified composite introgression from wild populations contributing to a substantial portion (4–32%) of the bread wheat genome, which increased the genetic diversity of bread wheat and allowed its divergent adaptation. Meanwhile, convergent adaptation to human selection showed 2- to 16-fold enrichment relative to random expectation—a certain set of genes were repeatedly selected in Triticum species despite their drastic differences in ploidy levels and growing zones, indicating the important role of evolutionary constraints in shaping the adaptive landscape of bread wheat. These results showed the genetic necessities of wheat as a global crop and provided new perspectives on transferring adaptive success across species for crop improvement.
What are the genetic mutations in wheat?
Genetic mutations in genes governing wheat threshability were critical for domestication. Knowing when these genes mutated during wheat evolution will provide more insight into the domestication process and lead to further exploitation of primitive alleles for wheat improvement. We evaluated a population of recombinant inbred lines derived from a cross between the durum variety Rusty and the cultivated emmer accession PI 193883 for threshability, rachis fragility, and other spike-related traits. Quantitative trait loci (QTL) associated with spike length, spikelets per spike, and spike compactness were primarily associated with known genes such as the pleiotropic domestication gene Q. Interestingly, rachis fragility was not associated with the Q locus, suggesting that this trait, usually a pleiotropic effect of the q allele, can be influenced by the genetic background. Threshability QTL were identified on chromosome arms 2AS, 2BS, and 5AL corresponding to the tenacious glume genes Tg2A and Tg2B as well as the Q gene, respectively, further demonstrating that cultivated emmer harbors the primitive non-free-threshing alleles at all three loci. Genetic analysis indicated that the effects of the three genes are mostly additive, with Q having the most profound effects on threshability, and that free-threshing alleles are necessary at all three loci to attain a completely free-threshing phenotype. These findings provide further insight into the timeline and possible pathways of wheat domestication and evolution that led to the formation of modern day domesticated wheats.
Where is durum wheat grown?
Durum wheat (Triticum turgidum L. subsp. durum (Desf.) van Slageren) is an important crop in the Mediterranean Rim, and it is deeply rooted in the history and tradition of this region. Recently, several studies that examined DNA markers on Mediterranean landrace collections have successfully elucidated the pathways of this crop across the Mediterranean Rim, but the historical frame is still rather diffuse. This paper aims at tracing the historical evolution of durum wheat throughout the Mediterranean Rim since its commencement as a crop until present times. A search was carried out through archaeological references where durum wheat remains were found. Historical descriptions about cultivation of this crop, references to products made from its grain, and articles interpreting DNA marker information from Mediterranean landraces were also consulted. The present article also examines the currently available durum wheat genetic resources. Durum wheat was domesticated in the Levant area. Phoenicians, Greeks, and above all Romans were active in the expansion and success of durum cultivation in all Mediterranean Rim that started displaced emmer by the mid first millennium BCE. Early Arab empire expanded in the area of durum wheat cultivation promoting food types based on semolina (dry pasta and couscous). Up to 1955 most durum areas in this area were planted with landraces, but several breeding programs were initiated in Italy, and later at CIMMYT and at ICARDA. Landrace collection and conservation efforts were carried out along the Mediterranean Rim countries to preserve the legacy of this crop.
What is the Q gene in wheat?
Main conclusion: Transformation from q to Q during wheat domestication functioned outside the boundary of threshability to increase yield, grains m-2, grain weight and roundness, but to reduce grains per spike/spikelet. Mutation of the Q gene, well-known affecting wheat spike structure, represents a key domestication step in the formation of today’s free-threshing, economically important wheats. In a previous study, multiple yield components and spike characteristics were associated with the Q gene interval in the bread wheat ‘Forno’ × European spelt ‘Oberkulmer’ recombinant inbred line population. Here, we reported that this interval was also associated with grain yield, grains m-2, grain morphology, and spike dry weight at anthesis. To clarify the roles of Q in agronomic trait performance, a functional marker for the Q gene was developed. Analysis of allelic effects showed that the bread wheat Q allele conferred free-threshing habit, soft glumes, and short and compact spikes compared with q. In addition, the Q allele contributed to higher grain yield, more grains m-2, and higher thousand grain weight, whereas q contributed to more grains per spike/spikelet likely resulting from increased preanthesis spike growth. For grain morphology, the Q allele was associated with reduced ratio of grain length to height, indicating a rounder grain. These results are supported by analysis of four Q mutant lines in the Chinese Spring background. Therefore, the transition from q to Q during wheat domestication had profound effects on grain yield and grain shape evolution as well, being a consequence of pleiotropy.
How do plants modulate the soil microbiome?
Plants modulate the soil microbiota by root exudation assembling a complex rhizosphere microbiome with organisms spanning different trophic levels. Here, we assessed the diversity of bacterial, fungal and cercozoan communities in landraces and modern varieties of wheat. The dominant taxa within each group were the bacterial phyla Proteobacteria, Actinobacteria and Acidobacteria; the fungi phyla Ascomycota, Chytridiomycota and Basidiomycota; and the Cercozoa classes Sarcomonadea, Thecofilosea and Imbricatea. We showed that microbial networks of the wheat landraces formed a more intricate network topology than that of modern wheat cultivars, suggesting that breeding selection resulted in a reduced ability to recruit specific microbes in the rhizosphere. The high connectedness of certain cercozoan taxa to bacteria and fungi indicated trophic network hierarchies where certain predators gain predominance over others. Positive correlations between protists and bacteria in landraces were preserved as a subset in cultivars as was the case for the Sarcomonadea class with Actinobacteria. The correlations between the microbiome structure and plant genotype observed in our results suggest the importance of top-down control by organisms of higher trophic levels as a key factor for understanding the drivers of microbiome community assembly in the rhizosphere.
What are the interactions between wheat and stagonospora?
Wheat-Stagonospora nodorum interactions involve pathogen-produced necrotrophic effectors (NEs) that are recognized by corresponding dominant host sensitivity genes to cause disease. The Snn1 gene, which confers sensitivity to the NE SnTox1, was previously mapped on the distal end of wheat chromosome 1BS. Here, we report the positional cloning and initial characterization of Snn1. High-resolution mapping and marker development in a population of 17,000 gametes derived from a cross between Chinese Spring (CS) and a CS-Hope 1B disomic substitution line delineated Snn1 to a 2.06 cM segment. Screening of the CS 1BS minimum tiling path pools with flanking markers led to the identification of a 2.5 Mb BAC contig spanning the Snn1 locus. BAC end sequences and genomic survey sequences were used to develop additional markers, which delineated Snn1 to a 0.16 cM segment encompassed by four BAC clones. Sequencing and analysis of the four BACs revealed six putative genes, five of which were excluded as candidates by recombination leaving one putative gene to cosegregate with Snn1. Sequence analysis of 15 EMS-induced resistant mutants provided final validation that Snn1 is a cell wall-associated kinase (WAK) gene with a cytoplasmic serine/threonine protein kinase domain and extracellular epidermal growth factor-calcium binding and galacturonan binding domains, all of which are essential for function. Further results regarding expression and characterization will be presented. This work allows us to gain better understanding of host-necrotrophic pathogen interactions, and together with related research demonstrates that S. nodorum can hijack different wheat genes and pathways to cause disease.
What was the first animal that people domesticated?
The discovery, they said, strongly suggests that the pig was the earliest animal that people domesticated for food. The diminished size of the molars was one of several clues that the transformation of wild boars into pigs was under way at that time. Radiocarbon analysis put the date at 10,000 to 10,400 years ago.
What did the Natufians depend on?
But if wild cereals were critical to the Natufians’ transition, the people at Hallan Cemi apparently depended on gathering nuts and seeds, hunting wild sheep and deer and raising pigs. The absence of any wild grains at the site was determined by Dr. Mark Nesbitt, a paleobotanist at University College, London.
What was the decline of pigs in Hallan Cemi?
In any case, the archeologists said, as soon as the people of Hallan Cemi began growing grain, there was a sharp decline in domestic pigs, which were gradually replaced by domestic sheep and goats. It was a necessity. Pigs compete with people for cereals. They could no longer be left to forage unattended near the village and fields, and they are not as easily herded as sheep and goats.
Why were pigs important to the villager?
Pigs may have been the villagers’ insurance against famine caused by any sudden shortage of nuts and fruits and wild game. In a pre-agricultural sedentary culture, Dr. Rosenberg said, such shortages posed a greater risk because the people had a more limited foraging and hunting range.
Is there any conclusive evidence for domestication of pigs?
No single piece of the pig evidence is conclusive, Dr. Redding reported, but all the clues together “are congruent with the early phases of the domestication of pigs.” Clue on Domestication
Where did the agricultural revolution take place?
Farming is thought to have happened first in the Fertile Crescent of the Middle East, where multiple groups of people developed the practice independently. Thus, the “agricultural revolution” was likely a series of revolutions that occurred at different times in different places.
What were the consequences of the agricultural revolution?
It has been linked to everything from societal inequality —a result of humans’ increased dependence on the land and fears of scarcity—to a decline in nutrition and a rise in infectious diseases contracted from domesticated animals. But the new period also ushered in the potential for modern societies—civilizations characterized by large population centers, improved technology and advancements in knowledge, arts, and trade.
Why did humans stop foraging?
There are a variety of hypotheses as to why humans stopped foraging and started farming. Population pressure may have caused increased competition for food and the need to cultivate new foods; people may have shifted to farming in order to involve elders and children in food production; humans may have learned to depend on plants they modified in early domestication attempts and in turn , those plants may have become dependent on humans. With new technology come new and ever-evolving theories about how and why the agricultural revolution began.
What was the shift to agriculture called?
Also called the Agricultural Revolution, the shift to agriculture from hunting and gathering changed humanity forever.
When did humans start domesticating animals?
Evidence of sheep and goat herding has been found in Iraq and Anatolia (modern-day Turkey) as far back as about 12,000 years ago.
When did humans start farming?
Humans are thought to have gathered plants and their seeds as early as 23,000 years ago, and to have started farming cereal grains like barley as early as 11,000 years ago . Afterward, they moved on to protein-rich foods like peas and lentils.
What was the role of hunters in the Neolithic era?
During the Neolithic period, hunter-gatherers roamed the natural world, foraging for their food. But then a dramatic shift occurred. The foragers became farmers, transitioning from a hunter-gatherer lifestyle to a more settled one.