These days, we have heard a lot about GMOs or genetically modified foods (GM foods). These foods also known as genetically engineered foods (GE foods), or bioengineered foods are kinds of foods that produced from organisms that have had changes introduced into their DNA using the methods of genetic engineering.

 

Truly, GMO is a method to change some traits of many living creatures. In other words, genetic engineering techniques allow for the introduction of new traits as well as greater control over traits when compared to previous methods, such as selective breeding and mutation breeding.

 

If we want to be familiar with the history of GMO and trace the steps of its growing, we should go back some centuries. While our ancestors didn’t know what GMO is and even didn’t have any concept of genetic, they were still able to influence the DNA of other organisms by a process called “selective breeding” or “artificial selection.”

 

Selective Breeding/Natural Selection

Like natural selection, selective breeding requires genetic variation on which to act. If the variation in a trait is strictly environmentally induced, then the selected variants will not be inherited by the next generation. Selective breeding also requires controlled mating. Thus, animals that are social and easily manipulated, such as bovid, sheep, and dogs, were easier targets for selective breeding than territorial species, such as cats and other carnivores. Cultures without a strong concept of property rights, such as those of pre-Columbian South America, were less likely to domesticate species because of their difficulty segregating different breeds.

 

Selective breeding differs fundamentally from natural selection in that it favors alleles (forms of a gene) that do not contribute favorably to survival in the wild. Such alleles are usually recessive, for otherwise they would not persist in wild populations. Selective breeding is essentially a process of increasing the frequency of rare, recessive alleles to the point where they usually appear in homozygous form. Once the wild-type alleles are eliminated from the population, the process of domestication has become irreversible and the domestic species has become dependent on humans for its survival.

The Birth of Modern Genetic Modification

Selective Breeding history

Selective breeding is evolution by human selection. The person who advised these terms called Charles Darwin. He described the process of choosing the organisms with the most desired traits and mating them with the intention of combining and propagating these traits through their offspring.

 

The earliest evidence of artificial selection of plants dates back to 7800 BCE in archaeological sites found in southwest Asia, where scientists have found domestic varieties of wheat. Selective breeding was invented independently in several different parts of the world, but its first appearance was in the Fertile Crescent, an alluvial plain between the Tigris and Euphrates Rivers.

 

Ten thousand years ago, hunter-gatherers in a western part of the Crescent known as the Levantine Corridor began to cultivate three cereal crops: einkorn wheat, emmer wheat, and barley. Each was descended from a different wild species. A thousand years later, hunters in the eastern region of Zagros began to herd goats. Within 500 years after that, cereal cultivation and goat herding had spread to the center of the Crescent and combined with sheep and pig herding to form a diverse agricultural economy.

 

Another selective breeding crop is well known in modern times as “sweet potato”. A recent study found that sweet potatoes were bred some 8,000 years ago out of the swollen parts of regular potato roots. In other words, they didn’t exist until humans tinkered with them.

 

Unconscious and conscious steps

The important thing we should consider in selective breeding is the separation between unconscious and conscious breeding. Unconscious selection, more common in ancient times, resulted in grains and seeds such as wheat, barley, oats, peas, and beans, and in animal traits such as speed and intelligence.

 

Methodical or conscious selection is oriented toward a predetermined standard, whereas unconscious selection is the result of biases in the preservation of valuable individuals. Methodical selection requires great care in discriminating among organisms and is capable of rapid change in specific traits, such as milk production or silk color. Unconscious selection, more common in ancient times, resulted in grains and seeds such as wheat, barley, oats, peas, and beans, and in animal traits such as speed and intelligence.

 

As Isobel Yeung reports for Vice: “Essentially, farmers have been modifying crops for thousands and thousands of years — we’ve been cross-breeding our best possible, most productive hybrids to create the best crops,” she said on Vice Debrief: Savior Seeds. “Theoretically [GMOs are] just the next level of agricultural advancement. What’s different is a new gene is being inserted into a crop which otherwise wouldn’t be there.”

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