The science of how to genetically modify crops is so complex that it is hard to know how to define it.
And it is the focus of a new book by a Cornell University professor and biologist who studies the subject.
“It is hard for people to grasp what the goal is,” said Dr. David B. Gieras, an expert in the field of crop biotechnology and the director of the Center for Biological Diversity’s Global Food Security program.
“In a sense, the goal has become to define something that is not yet defined.”
The concept of “genetically modified” crops originated in the 1980s as the United States grappled with the introduction of GMO crops, such as corn, soybeans and cotton, into food production.
But the term has evolved as researchers and farmers have learned more about how to modify plants to meet different nutritional requirements.
GMOs have been applied to crops since the 1990s and have become a popular tool for farmers to help feed hungry populations, such the United Nations’ Millennium Development Goals, as well as to combat global warming.
Some experts say the technology has led to better nutrition for consumers, but it has also been linked to environmental and health concerns.
A growing number of countries, including Canada, have begun labeling GMO crops and some states have banned the planting of genetically modified crops.
“GMOs are the new, ubiquitous food,” said Danilo Venezia, an associate professor of agricultural and food policy at Cornell and author of “Genetically Modified: The Future of Agriculture and the Food System.”
“They are so widely used that there’s a whole ecosystem of GMOs that are becoming increasingly important.”
“The new way to grow food is genetic engineering” Dr. Venezio said.
“The idea of using genes from a variety of different organisms to produce a particular variety of food, and then having the food be safe for consumption, is the same idea as using a chemical in a chemical factory.”
Some GMO crops have been approved by regulators, such a corn variety called Bt cotton, that is resistant to some of the most common herbicides.
“If you’re going to use genetically modified plants, you’re probably going to want to have an herbicide resistant crop that’s tolerant to that herbicide,” Venezios said.
It’s not clear how well the new technology works in the wild, and whether farmers can use it safely.
A recent report by the University of Missouri Agricultural and Natural Resources Research Department found that using the herbicide Roundup, which is approved for use on some GMO crops in the U.S., increased the rate of death and disease from glyphosate-resistant corn by 10 percent.
The report noted that Roundup-resistant crops are now available in only about 30 countries, with the majority of them in Africa.
That’s because of restrictions in countries like China and South Korea.
But Dr. Giers said the technology is becoming increasingly popular in the United Kingdom and Canada, where farmers have been planting GMOs since the mid-1990s.
“We have started to see farmers using genetically modified corn to grow a variety that is less likely to be killed by Roundup than conventional corn,” he said.
He said many farmers now plant the variety that contains a modified version of the gene from a different plant, known as a heterozygote.
The trait is similar to the way plants that are heterozygous for the gene in one species have a more aggressive tendency to develop cancer.
The research, by the U of M’s Environmental Institute, was funded by the National Science Foundation and the National Institutes of Health.
“Genetic modification has become the new food,” he added.
“People are starting to do it more and more often.”
In the U, there are currently only three types of GMO corn: Bt varieties, which contain the GM corn bt technology, and Roundup-tolerant, which are genetically modified varieties.
Bt corn has been growing at a rapid rate in the past decade, and there is growing concern about its impact on the environment.
A 2014 study found that farmers who grew Bt maize were three times more likely to suffer from corn allergies.
“These are potentially dangerous plants that we can’t grow in a laboratory and we can not use for food,” Dr. Bieras said.
The National Research Council, a nonprofit research agency, has also reported that GM corn is not the same as conventional corn.
In fact, the research council said, there is no evidence that Bt is any better or worse than conventional crops.
And a 2015 study published in the journal Environmental Research Letters found that genetically modified rice, a common food staple, was also more toxic than conventional rice.
The council also found that the genetic modification of GM rice could be detrimental to the environment, and that the development of genetically engineered rice could result in greater pesticide use and a reduction in yields.
Dr. Michael Siegel, a professor of food and agriculture at Cornell, called the report a “bogus study.”