Get educated about GMO’s with Elizabeth Bent! – @US_Conversation #science

Not all GMO plants are created equally: it’s the trait, not the method, that’s important

Elizabeth Bent, University of Guelph

Many people have strong opinions about genetically modified plants, also known as genetically modified organisms or GMOs. But sometimes there’s confusion around what it means to be a GMO. It also may be much more sensible to judge a plant by its specific traits rather than the way it was produced – GMO or not.

This article is not about judging whether GMOs are good or bad, but rather an explanation of how plants with modified genomes are made. (There are non-plant GMOs, but in this article we will only refer to plant GMOs.) First of all, it’s necessary to define what we mean by a GMO. For the purposes of this discussion, I’m defining GMOs as plants whose genetic information (found in their genomes) has been modified by human activity.

Humans have changed the genomes of virtually all the plants in the grocery store

If we think of GMOs as plants that have genomes modified by humans, then quite a lot of the plants sold in any grocery store fit that description. But many of these modifications didn’t occur in the lab. Farmers select plants with superior, desirable traits to cultivate in a process known as agricultural evolution. Thousands of years of traditional agricultural breeding has changed plant genomes from those of their original wild ancestors.

Broccoli, for example, is not a naturally occurring plant. It’s been bred from undomesticated Brassica oleracea or ‘wild cabbage’; domesticated varieties of B. oleracea include both broccoli and cauliflower. Broccoli, along with any seedless variety of fruit (including what you think of as bananas), and most of the crops grown on farms today would not exist without human intervention.

However, these aren’t the plants that people typically think of when they think of GMOs. It’s easy to understand how farmers can breed better plants on farms (by choosing to plant seeds from the biggest or best-yielding plants, for example, imposing artificial selection on the crop species) so even though this activity changes plant genomes in ways nature wouldn’t have, most people don’t consider these plants GMOs.

Creating “lab” GMOs

Once plant genes had been studied enough, researchers could turn to backcrossing. This technique involves breeding the offspring back with the parents to try to get a desired, stable combination of parental traits. Genes previously linked to desirable plant traits, such as higher yield or pest-resistance, could be identified and screened for using molecular biology techniques and linkage maps. These maps lay out the relative position of genes along a chromosome, based on how often they are passed along together to offspring. Closer genes tend to travel together.

Researchers used molecular markers – specific, known gene sequences, present in the linkage maps – to select individual plants that contained both the new marker gene and the greatest proportion of other favorable genes from the parents. The combinations of genes passed to offspring are always due to random recombination of the parents’ genes. Researchers weren’t able to drive particular combinations themselves, they had to work with what arose naturally; so in this marker-assisted selection approach, there’s a lot of effort and time spent trying to find plants with the best combinations of genes.

In this system, a laboratory needs to screen the genomes, using molecular biology methods to look for particular gene sequences for desirable traits in the bred offspring. Sometimes a lab even breeds the plants in cases using tissue culture – a way to propagate many plants simultaneously while minimizing the resources needed to grow them.

Inserting non-plant genes into GMOs

In the early 1980s, the plant biotechnology era began with Agrobacterium tumifaciens. This bacterium naturally infects plants and, in the wild, creates tumors by transferring DNA between itself and the plant it has infected. Scientists use this natural property to transfer genes to plant cells from an A. tumifaciens bacterium modified to contain a gene of interest.

For the first time, it was possible to insert specific genes into a plant genome, even genes that do not come from that species – or even from a plant. A. tumifaciens does not affect all plants, however, so researchers went on to develop DNA-transferring methods inspired by this system which would work without it. They include microinjection and “gene guns,” where the desired DNA was physically injected into the plant, or covered tiny particles that were literally shot into the nuclei of plant cells.

A recent review summarizes eight new methods for altering genes in plants. These are molecular biology techniques that use different enzymes or nucleic acid molecules (DNA and RNA) to make changes to a plant’s genes. One route is to alter the sequence of a plant’s DNA. Another is to leave the sequence alone but make other epigenetic modifications to the structure of a plant’s DNA. For instance, scientists could add arrangements of atoms called methyl groups to some of the nucleotide building blocks of DNA. These epigenetic modifications, while not altering the order of the DNA or of genes, change how genes can be expressed and thus the observable traits a plant has.

GMO doesn’t mean glyphosate-resistant

Calling a plant a genetically modified organism means only that – its genome has been modified by the activity of humans. But lots of people conflate the idea of a GMO plant with one that’s been created to be resistant to the herbicide glyphosate, also known by the brand name Roundup. It’s true that the most well-known GMO crops currently grown contain a gene that makes them resistant to glyphosate, which allows farmers to spray the chemical to kill weeds while allowing their crop to grow. But that’s just one example of a gene inserted into a plant.

It’s sensible to evaluate GMOs not on how they are made, but rather on what new traits the modified plants have. For instance, while it can be argued that glyphosate resistance in plants is not good for the environment because of increased use of the pesticide, other GMOs are unlikely to cause this problem.

For example, it’s difficult see how the controversial golden rice, which has been engineered to produce vitamin A in the rice grains to be more nutritious, is worse for the environment than ordinary rice. GMOs have been developed to express a pesticide permitted in organic farming: Bt toxin, an insecticide naturally produced by the bacterium Bacillus thuringiensis. While this may reduce pesticide use, it may also lead to the evolution of Bt-resistant insects. And there are GMOs which have improved storage characteristics or nutritional content, like “Flavr Savr” tomatoes, or pineapples that contain lycopene, and tomatoes that contain anthocyanins. These compounds are ordinarily found in other fruits and are thought to have health benefits.

The so-called “fish tomato” contains an antifreeze protein (gene name afa3), found naturally in winter flounder, that increases frost tolerance in the tomato plant. The tomato doesn’t actually contain fish tissue, or even necessarily DNA taken from fish tissue – just DNA of the same sequence present in the fish genome. The Afa3 protein is produced from the afa3 gene in the tomato cells using the same machinery as other tomato proteins.

Is there any fish in the tomato plant? Whether DNA taken from one organism and put into another can change the species of the recipient organism is an interesting philosophical debate. If a single gene from a fish can make a “fish tomato” a non-plant, are we human beings, who naturally contain over a hundred non-human genes, truly human?

The Conversation

This article was originally published on The Conversation.
Read the original article.

AAAS and Pew poll confirms differing opinions between public and scientists on science-related issues.


If you haven’t already seen the public and scientist opinion poll put out yesterday by AAAS and Pew Research Center, its a must see (the featured tweet above is satire based on a CauseScience hashtag)! If you’ve been paying attention, there isn’t anything overly surprising – scientists and the general public have differing views on many science-related issues. A nice summary of the poll is here at Some major highlights of the in-depth poll include:

– Should animals be used in research? 89 percent of the scientists said yes, as opposed to 47 percent of the public.

– Is it safe to eat foods grown with pesticides? 68 percent of the scientists agreed, compared with 28 percent of the public.

– Is climate change caused mostly by human activity? 87 percent yes from the scientists, 50 percent yes from the public.

– Have humans evolved over time? 98 percent yes from the scientists, 65 percent yes from the public.

– Should more offshore oil drilling be allowed? 32 percent yes from the scientists, 52 percent yes from the public.

– Should more nuclear power plants be built? 65 percent yes from the scientists, 45 percent yes from the public.

– Should parents be allowed to decide not to have their children vaccinated? 13 percent yes from the scientists, 30 percent yes from the public.

In good news from the poll:

Science holds an esteemed place among citizens and professionals. Americans recognize the accomplishments of scientists in key fields and, despite considerable dispute about the role of government in other realms, there is broad public support for government investment in scientific research.

Get out and vote! #science #climate #GMO #vaccines #NIH #NSF

Get out and vote today!


Yikes! David Remnick breaks down Vandana Shiva’s criticism of Michael Spector’s New Yorker article @GeneticLiteracy


CauseScience previously posted the terrific New Yorker article by Michael Specter profiling anti-GMO activist Vandana Shiva, and her science denialism. The Genetic Literacy Project has continued to follow this story, and the scathing response from Shiva and her followers, and have now posted an amazing rebuttal to Shiva’s response from New Yorker editor David Remnick. If you enjoy a logical, well-reasoned point-by-point rebuttal, check it out! 

Just a sample of Remnick’s response:

One hardly needs to hold a Ph.D. in physics to become an effective environmental activist, as you have demonstrated. Yet, when a prominent figure, such as yourself, is described for decades—in interviews, on web sites, in award citations, and on many of your own book jackets, as having been “one of India’s leading physicists” it seems fair to ask whether or not you ever worked as one.

It is fine to express anti-GMO viewpoints, but when misleading statements, false science, and conspiracy theories are your evidence, expect them to be called out. Thanks to the Genetic Literacy Project for watching this and posting about it!


Michael Specter explains the altered reality of anti-science GMO opponents #science #VandanaShiva


Michael Specter has written an amazingly well researched (trips to rural India) piece for The New Yorker about anti-GMO and anti-science crusader Vandana Shiva. While Specter focuses on Shiva, his article looks broadly at GMO foods and the anti-science movement that opposes them. While I am certainly not a supporter of Monsanto and their legal tactics, this article truly demonstrates the bizarre anti-science and science denial propaganda utilized by opponents of GMOs. It is a bit of a long read, but more than worth the time. Below is one of my favorite passages from the article,

Monsanto is certainly rich, but it is simply not that powerful. Exxon Mobil is worth seven times as much as Monsanto, yet it has never been able to alter the scientific consensus that burning fossil fuels is the principal cause of climate change. Tobacco companies spend more money lobbying in Washington each year than Monsanto does, but it’s hard to find scientists who endorse smoking. The gulf between the truth about G.M.O.s and what people say about them keeps growing wider. The Internet brims with videos that purport to expose the lies about genetically modified products. Mike Adams, who runs a popular Web site called Natural News, recently compared journalists who are critical of anti-G.M.O. activists such as Shiva to Nazi collaborators.

Great Ted Video featuring Michael Specter! The danger of #science denial

I saw this posted on ‘2012 and all that’ blog, check them out!

Fantastic Ted Talk video on science denial. It applies equally to all denial and anti-science movements: climate denial, food conspiracy, Big Alterna and Big Organic, creationism, anti-vaccine cranks and many others. Please watch the video because not only does he do yet another necessary takedown, he also shows the intimidating actions used by some anti-science groups. Vaccine-autism claims, “Frankenfood” bans, the herbal cure craze: All point to the public’s growing fear (and, often, outright denial) of science and reason, says Michael Specter. He warns the trend spells disaster for human progress.

GMO crop pictures… worth more than a thousand words! #science

Crop depot

Ever wonder why there is all the fuss about GMOs? Check out this article on Food For Thought blog with pictures of GMO crops. Then go check out the GMO Crop Photo Depot provided on the website of Dr. Wayne Parrott, Professor in the Department of Crop and Soil Sciences at the University of Georgia.