Debunking Anti-GMO

Anti-GMO Activist Roseanne Barr Struggles to Defend Her Claims

In Anti-GMO Activist Roseanne Barr: GMOs caused Papaya Ringspot Virus, I explained how the papaya ringspot virus (PRSV) almost totally destroyed the papaya industry on Hawaii and that researchers saved it by developing a genetically modified papaya that was resistant to PRSV. I also criticized the claim made by anti-GMO activist Roseanne Barr that the genetically modified papaya caused/created PRSV. I pointed out that the virus was first reported on Oahu in 1945 (although it can be traced back at least 500 years ago to Asia) and it was not until 1998 that the genetically modified papaya was released, making her scenario impossible without a time machine.

I examined her response to my criticism in Anti-GMO Activist Roseanne Barr Goes Off the Deep End and found it deeply unsatisfying. Barr did not reply to the actual arguments I made, instead asserting that I was a Monsanto shill. She tried to spread biotechnology fear-mongering and mistrust of mainstream scientific research as well as performed several logical fallacies, including hasty generalization and the post hoc fallacy.

This post examines some of Roseanne Barr’s reactions since I published my previous posts about her claims about genetically modified papayas and the PRSV.

Roseanne Barr calls for backup

Presumably stumped by the scientific and historical facts I presented about the situation, Roseanne decided to ask her twitter followers for help:

Roseanne calls for backup

Barr is still of the mindset that I have provided her with “false science”. She calls me a “science debunker”, presumably a debunker of what she thinks is “true science” i.e. stuff that would seem to support her contrarian views on genetically modified papaya and the PRSV. It is also fascinating that, despite being criticized for it, she still asserts that I am a Monsanto shill. She has now also blocked me on Twitter.

Unwittingly, tweeting a link to my blog to her followers (over 200k at the time of this writing), she gave both my blog and the scientific facts against her a lot of exposure. Thanks for the help, Roseanne!

Roseanne Barr confuses cross protection with genetic modification

Cross protection is a strategy whereby plants are vaccinated using a milder version of the virus so that it can build up a protection against the more severe strains (Zhou and Zhou, 2012). This is a completely separate approach from how the papaya was genetic modification. The latter involved inserting a gene into the papaya genome.

After allegedly staying up for most of the night reading about genetically modified papaya on Hawaii, Barr linked to an article on a vegan website and tweeted the following:

Roseanne links a pro-GMO vegan blog

Barr apparently makes a big deal out of the fact that cross protection research started in the late 1970s. However, as we saw, cross protection (which turned out to not be that effective) is a completely different approach from genetic engineering.

Also, that website that Barr linked to was actually a pro-GMO website and the blog post clearly stated that the genetically modified papaya was developed as a response to the decimation caused by the PRSV. The GMO vegans reached the following conclusion about genetically modified papaya on Hawaii: “It seems that in the case of papaya at risk for PRSV-p [the variant that attacks papayas – Emil’s note], genetic engineering is the most appropriate solution – especially in areas where papaya is an important source of nutrition.”

Clearly, Barr did not read that much of that post because otherwise she would have understood that it actually massively contradicted her position. Presumably she was very tired at the time.

A little glimpse of hope?

A twitter user by the name of Rob Bairos confronted Barr with the time machine argument and encouraged her to give up and admit that she was wrong:

Roseanne is challenged by Rob Bairos

Roseanne replied that she would retract her claim and admit that she was wrong if she could not find scientific studies supporting her viewpoint.

Roseanne says she might admit that she was wrong...

This is a fairly admirable thing to say, especially for someone like Roseanne Barr who is quite deep in the anti-GMO swamp. The real crux of the matter is this: will she admit that she was wrong when she inescapably fails to find any evidence against the mainstream scientific account of the PRSV and the genetically modified papaya on Hawaii?

At any rate, it is going to be very interesting to see what happens.


Zhou, Changyong, & Zhou, Yan. (2012). Strategies for Viral Cross Protection in Plants. In J. M. Watson & M.-B. Wang (Eds.), Antiviral Resistance in Plants (Vol. 894, pp. 69-81): Humana Press.


Debunker of pseudoscience.

3 thoughts on “Anti-GMO Activist Roseanne Barr Struggles to Defend Her Claims

  • Pingback: Hawaiian Papaya Smackdown on Twitter | SLEUTH 4 HEALTH

  • ‘The real crux of the matter is this: will she admit that she was wrong when she inescapably fails to find any evidence against the mainstream scientific account of the PRSV and the genetically modified papaya on Hawaii?’
    Emil, I wouldn’t hold your breath!! Rosanne still thinks she nailed it when she sang the national anthem;-)
    I’ve been participating on these boards since the Monarch butterfly debacle. When these folks like Rosanne are confronted with logic (or in this case the plain truth) the original debate goes by the wayside and it becomes a discussion about affiliations.
    Anyone who disagrees with these people must be a shill. Actually, I view this as a victory. It usually means they can’t reply with a logical argument and I’ve gotten under their skin. Quite satisfying!!

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