Land ploughed by these horses may grow domestic barley, which has been selectively cultivated over millennia from its wild ancestor. The horse and barley are GMOs.
GM by direct manipulation of DNA began in the 1950s using radiation to cause mutagenesis - a result of this that is still with us is the red grapefruit. What we tend to call GE these days are the laboratory processes that were pioneered from the mid-1990s onwards.
Modern GM consists of manipulating, removing or replacing genes within the DNA of organisms using chemical and mechanical methods. Progress over the past 20 years has been huge and it is now possible to pluck out individual genes or rebuild DNA chains with great accuracy. These methods can achieve the same results as the earlier selective breeding methods but much faster.
Laboratory-based GM has another difference. Selective breeding for a particular trait brings together ALL of the genes of the two organisms and while emphasising the desired trait it may inadvertently switch on or switch off other genes, causing unwanted effects. We only need to look at dogs that have been bred for a particular posture that now have weak bones.
However, as the science of GM has become more precise, unwanted effects have become more predictable and avoidable.
Dr Winkworth debunked a few myths. He showed a Photoshop image of a goldfish crossed with an apple - such links between animal and plant genes are simply not possible. The image was meant to be comical, but the lack of laughter indicated that some of the audience were not convinced.
Dr Winkworth pressed on to murkier waters, asking the question: "Are GMOs safe to eat?" He spoke about bananas, a fruit regarded as a natural energy food for growing children. What could be safer?
The banana that we eat has three strands of DNA meaning it cannot reproduce sexually. Cultivation is by transplanting part of a mature plant, making it necessary for banana plants to have up to 70 spray applications over a season to keep diseases and insects away.
Celery, another "safe" food, contains psoralen which is linked to painful photodermititis in people regularly handling the vegetable and cancer in mice. There are few, if any, foods that can be considered totally safe.
Dr Winkworth told us that around 2000 studies of GM safety by independently funded and respected scientific bodies indicated that GM foods are no more dangerous than the foods we already eat on a daily basis.
The study by Van Eenennaam and Young in 2014 looked at data for one hundred billion animals fed on GM livestock feed between 1983 and 2011. It found no good or bad health or nutritional effects attributable to GM feedstuff.
A further study cited by Dr Winkworth and carried out by Kyndt et al in 2015 found that all cultivated sweet potato (kumara) clones carry DNA that has transferred from a bacterium. This transfer occurred naturally in the past few thousand years and caused desirable traits that were selected for during domestication of the plant. The transferred DNA is not present in the closely related wild relatives, throwing into question the idea of "natural" and "unnatural" foods with respect to GM.
Ask people whether they will eat GM foods and many will say "No". Ask them why and you get vague answers - not good for you, not proven to be harmless, unnatural and so on.
This is understandable because people outside the scientific community usually do not have the time or training to fully understand developments.
Dr Winkworth said that even in his own field there were too many papers and studies published for him to always keep up with new ideas.
Other issues of importance such as climate change are also too complex for most people understand. So how can the general public make informed decisions with respect to such issues? Are we thrown back on to trusting the judgment of academics who may have concerns about job security if they come up with answers which politicians or big industry do not like? To some extent, yes.
However, we also have a duty to be as well-informed as possible and make sure our children are as scientifically literate as they can be - and I do not simply mean passing school science exams.
The only stupid question is the one you did not ask.
**Frank Gibson is a semi-retired teacher of mathematics and physics who has lived in the Whanganui region since 1989.
