Join Dr. Kat Arney as she visits Gregor Mendel’s garden, asks why an onion needs five times as much ‘junk DNA’ as you do, and takes a look at the science behind – and the backlash against – the world’s first commercial GM food crop, Flavr Savr tomatoes.
Known as the ‘father of genetics,’ Gregor Mendel’s detailed work on pea hybrids helped him to work out the laws of inheritance. He announced his findings in 1865 to his local scientific society in what’s now Brno in the Czech Republic, but they went under the radar until they were rediscovered in the early 20th century. But not everyone was convinced by Mendel’s explanations of genetics, and it soon became clear that people are not peas – and even peas are not peas.
The onion test is a much more modern invention, devised by T. Ryan Gregory as a way of thinking about non-coding (“junk”) DNA in the genome: if a humble onion has five times more DNA than humans. So if you’re a researcher who thinks that non-coding DNA has a particular function in the genome, then you need to explain why an onion needs about five times more of it than a human to do the same thing.
Finally, genetically modified crops first made their appearance on supermarket shelves in the mid 1990s in the form of canned products made from Flavr Savr tomatoes, which carried an extra gene enabling them to ripen on the vine and stay fresher for longer after harvesting. After facing a public and media backlash, Flavr Savr products lasted just three years on the market, with owner Monsanto citing poor harvests and high shipping costs as the reason for their failure. As companies continue to develop GM food crops around the world, including tomatoes, what can we learn from the story of Flavr Savr?
Genetics Unzipped is presented by award-winning science communicator Dr Kat Arney and produced by First Create the Media for the UK Genetics Society. Follow Kat on Twitter @Kat_Arney and Genetics Unzipped @geneticsunzip