Do you know what mosquitoes and bees have in common? Let me tell you, their threat to biosecurity goes further than just a sting! In this short post you can read about what can go wrong if we do not manage the risks involved in modifying the animals in the world around us.
You have probably heard about the recent Zika outbreak in South America, which was all over the news. Zika infected mosquitoes terrorize the continent and cause so much trouble that they will influence the demographic composition of the population. For those of you who missed all that, Zika is a virus which is spread by the Aedes Aegypti mosquito. It reached South America in 2015, and has spread very quickly across the continent. The virus causes the Zika fever, a rather innocent fever which has only mild symptoms and can be treated by taking rest. However, the commotion was all about the alleged causal relation between Zika fever and microcephaly, a disorder which causes children to be born with a skull deformation. This caused so much fear of disabled children that even official government policy asks women to postpone their pregnancy.
Fortunately, there are companies like the British biotech firm Oxitec. With the latest advances in science and technology, they have been able to genetically modify the Aedes mosquito so that it is unable to reproduce. Currently they are helping the inhabitants of a town called Piraciaba to combat the mosquitoes. Employees of Oxitec breed many of these genetically modified disease transmitters and set them free all across the city. Some days they release up to 250,000 mosquitoes a day. The technique is still under development and has not yet been scientifically proven, but it works! The number of Aedes Aegypti mosquitoes has dropped with 82% according to Oxitec. Another problem solved, and another victory of man over nature.
Lets now turn to another story which was in the news, although somewhat longer ago. This is the story of the Africanized honey bee. In the 1940s and 50s, honey was a major export product for several countries in the Americas. The Yucatán region in Mexico for example was the largest honey exporting region in the world. However, beekeepers made use of the European honey bee. And as it turned out, this bee was having trouble to adapt to the warmer regions of the continent. Biologist Warwick E. Kerr imported African honey bees to crossbreed them with the European species, in order to create honey bees that were able to produce honey in the regions with a tropical climate, . And with success. A new species of Africanized bees was ‘made’, which was far superior in collecting honey and pollinating flowers than the European bees were. So far another success story where science is used to shape nature in a more comfortable way for humanity.
The troubles began however when in October 1957 a visiting beekeeper unknowingly removed the excluder screens which were used to keep the bee queens from getting out of the facility. This resulted in the accidental release of 26 swarms of the Africanized honey bees. And because these bees were superior to other bees in many respects, they turned out to be particularly invasive. In fact, they were so well adapted and spread so quickly that the Africanized bees have earned the worldwide reputation of being one of the most successful biologically invasive species. Since their release, they have conquered the whole continent, even reaching most of the southern states of the United States where they become known as killerbees because of their aggressive behaviour.. Today, in some regions Africanized bees now make up to 85% of the total bee population.
So what’s the moral of this story? I think you might have some idea by now. The bees were only a result of crossbreeding. Do you know what can happen when we genetically modify a species? Are we capable of handling biosecurity issues? One person making a mistake can already lead to a gray goo scenario. This because any change we make in biological life forms that are successful will have effects on our environment that transcend generations and national borders. In the Zika case, if we take a look at the politics behind the decision making, it might not ease our troubled mind. Can we really expect the Brazilian government and the governor of Piraciaba to be very cautious and prudent, when faced with serious economic problems and their citizens demanding them to solve this health crisis in return for another term in office? And besides that, should we try to solve some immediate health problems by risking the creation of a super mosquito which will trouble our world for generations to come? Nowadays we have technological capabilities which seem to be able to solve so many of our problems. But if we are not able to manage the risks that come with this kind of responsibility, it might be wise to take a step back. Our kids also deserve a world without a killer mosquito.