For many years, the topic of genetic modification has been one that can swing from that of great hope for the future of human technological progress to one of the subjects of the most absurd science fiction horror movie tropes. The reason for this vast hyperbole is because of the general lack of knowledge the general public has about what our current achievable gene manipulation technologies are (and their current significant limitations) but also the excitement of how these technologies may develop in the future.
Mankind has been tinkering with genetics for a very long time through artificial selection and selective breeding of livestock and crops, though they wouldn’t begin to understand the mechanisms until the late 19th/early 20th century through work done by Gregor Mendel and his successors. Since then, we have sequenced genomes and gained the ability to manipulate certain genes and even introduce or remove genes from an organism. For the most part, the target of these manipulations remain the same livestock and crop species that we have manipulating for hundreds of years already. However, in the last year or so, new gene-editing technologies have gained a lot of press and even coverage on talk shows, the most publicised of these technologies is CRISPR. I encourage you to read up on the specific mechanisms of how this technology works, as it is fascinating. What’s even more interesting is that these new technologies are opening up new fields and targets for genetic manipulation beyond the traditional scope of livestock and crops. While there is great interest in CRISPR’s potential ability to treat certain human genetic illnesses, it is also being used to target other organisms, specifically pests or insects that may be vectors for disease. At Imperial College in London, there is some very interesting work being done currently to target mosquitoes that are the vector for malaria.
It all sounds great and very hopeful right? Environmental systems, on either a macro (ecosystem) or micro (single organism), can be very sensitive and unpredictable and history is replete with examples of well-intentioned human intervention that had unforeseen negative consequences. A famous example was the introduction of cane toads from Hawaii to Australia. Australian farmer’s crops were suffering extensive damage from several species of native scarab and cane beetle. Unable to control the infestation, the cane toad was introduced in the 1930’s as it was known to be a voracious predator of herbaceous beetles in its native Hawaii. What the hapless farmers did not predict was that once introduced into the totally novel Australian ecosystem, was that the cane toad would become a voracious predator of many other indigenous Australian insects (most which were not pests) and even small mammals. The cane toads also had no predators of their own in Australia, and their numbers exploded as they ate their way through Australia.
What parallels do you think can be drawn between this example, now almost 100 years old, and today’s experiments in gene editing? What recommendations would you make to the scientists experimenting today to avoid unforeseen consequences?