If you could wipe out a whole species, would you?

If I asked a room of 100 people what their fears are, there’s a pretty high chance I would get answers like “spiders” and “snakes” as a high percentage. So the question I pose is; if we could choose a species or family from the family tree to wipe of the planet, would you?

The two members of the animal kingdom mentioned above might give some people the heebie-jeebies, but the fact is that they each are a fundamental part of a food chain, functioning in their own ecological niche. Wipe out spiders for example, and several bird and reptile species would soon follow as the food web the spiders cling to is sent crashing down.

However their may be a family that can be completely eradicated without any serious repercussions, and furthermore their removal from the biosphere could save millions of lives.

The Three Mosqui-teers

There are three really common species of mosquito; Anopheles quadrimaculatus, Culex pipiens, and Aedes aegypti. Only the females bite people, and they can sense you by your sweat and the smell of your breath. More worryingly, they are considered the deadliest animal in the world, as the Anopheles mosquito transmits malaria – a terrifying disease caused by certain members of the vast Plasmodium genus of microorganism – which kills roughly a million people every year. They can also transmit Dengue fever, West Nile virus, yellow fever, and many more illnesses. Naturally, these ‘little flies’ are quite a menace and something needs to be done.

You’re probably thinking “but surely they have a place in some ecosystem, they must have evolved some purpose” and you’d be right – they actually pollinate a few different species of flowers, such as Goldenrods and Blueberries. However both of these plants can easily be pollinated by other insects, and they have a really diverse array of pollinators. Jittawadee Murphy from Walter Reed Army Institute of Research, who has been studying mosquitoes for 20 years, says she would gladly see them wiped from the Earth. In a paper published in popular journal Nature back in 2010, medical entomologist Carlos Brisola Marcondes from the Federal University of Santa Catarina in Brazil stated “The elimination of Anopheles would be very significant for mankind.” She also said that the world would be far more “secure” for mankind should the Anopheles mosquito be wiped out.

Basically, even the people who’s careers revolve around them hate these little winged blood-suckers.

Hatching a plan

Recent breakthroughs mean that it may soon be possible to remove the pesky mosquitoes from existence. An Oxford-based biotechnology company, Oxitec, recently published results from a trial involving sterile male mosquitoes. Oxitec breeds mosquitoes at its three factories – two of which are in Brazil where Dengue fever is still rampant. They then identify and separate the males. However these are no ordinary males – they cannot create viable offspring

The mosquitoes’ genetic code has been modified by the scientists so that the males can be released, mate with wild females (and therein compete with wild males) but produce offspring which will die well before they reach adulthood due to a self-limiting gene that they inherit from their parent. Given enough time, the GM males would hopefully out-breed the wild males and the species reproduction rate would grind to a halt before beginning to plummet. The recessive “knockout genes” would only be introduced to Anopheles (malaria spreaders) and Aedes (yellow fever, Dengue fever, elephantiasis and so on) and would only result in a decrease of 1% in the diversity of the Culicidae family to which these mosquitoes belong. Biologist Olivia Judson who has been researching knockout genes (when genes are made inoperative)  and various mosquito control methods has suggested that should current control programs fail, we can’t allow people in third world countries to suffer any further and that “we should consider the ultimate swatting”.

A research paper published in the Journal of Economic Entomology titled “Pest Control by Genetic Manipulation of Sex Ratio” by Paul Schliekelman et. al. back in 2005 was already speculating and modelling the concept of dramatically increasing the number of males in a population (along with other potential techniques involving modification of female phenotypes), so one could suggest we use the technique of GM sterile mosquitoes and increasing the percentage of males in a population to accelerate this “ultimate swatting”.

Should these methods be introduced, we could be looking at a mosquito free world within our lifetime. However with our still limited view of the entire ecosphere the repercussions could be immenseThere are, however, some other upcoming methods for preventing malaria that could offer a far better solution.

Offense vs Defense

Many would argue that mankind does not have the “right” to remove a species from the face of the planet, regardless of how annoying and dangerous they might be. We’ve already driven so many species close to extinction (and we may be heading in that same direction ourselves) that we should be focusing on other methods of malaria prevention and should stay away from “playing god”. Many experts in ecology have also raised the point that we do not know the full scope of mosquito uses and their potential niche in the environment, and that they could easily be a reliable food source for species of freshwater fish species that remain undiscovered or barely catalouged deep in the freshwater lakes of Africa.

While this post has mainly considered the offensive approach of eradication, I’d also like to highlight the defensive approaches of preventing malaria-related deaths which are currently being researched or are already implemented. A recent report by the World Health Organization highlighted a malaria vaccine called RTS,S/AS01 which is being developed by GlaxoSmithKline (GSK) and the PATH Malaria Vaccine Inititative (MVI) and is currently being supported by the Bill & Melinda Gates Foundation (yes, THAT Bill Gates). It is currently 5-10 years ahead of other candidates and if licensed it will be the first ever licensed vaccine against a parasitic disease in humans!

If you remeber from earlier, I mentioned the Plasmodium parasite that causes malaria – there’s actually a few different species of this parasite that infect humans when bitten by a mosquito, find their way to the liver to reproduce and then go out hunting for red blood cells. The vaccine is showing high efficacy against the P. falciparum, which is quite common in sub-Saharan Africa and is especially dangerous. The vaccine will unfortunately not offer any protection against other forms of malaria, for example that caused by P. vivax.

The main problem with this new vaccine is that it requires at least 4 doses to be effective and the timescale of immunisation for infants and newborns will have to be revised completely. Additionally, there is a growing “anti-vaxxer” movement in the Western World and should this ridiculous and harmful belief that vaccines are bad spread to the developing world, the vaccination process could prove useless and funding for clinical trials could be placed in jeopardy. I do feel, however, that the anti-vaxxer movement is highly unlikely to spread to the third world, as the people supporting the movement don’t deal with widespread infectious disease as much as those living on the African continent and in South America. Additionally, anti-vaxxers have enjoyed the cushioned realm of herd immunity and their own active acquired immunity (the type of immunity you get from infection or vaccination) for so long that they don’t remember or haven’t experienced the devastation of polio and measles, yet those in the second and third world know all too well about these diseases. The anti-vaccination movement is, in essence, a product of privilege and classism (this rant will be continued in a future blog post).

Critics of the “ultimate swatting” and of the novel vaccine have highlighted that mosquito nets have been proven to be more effective at bringing down the incidence of malaria in the developing world. The WHOPES Phase II or WHO Pesticide Evaluation Scheme (a 4 phase testing and evaluation program assessing the safety and efficacy of public health pesticides) approved mosquito nets can last 4-5 years and slowly release insecticide in such a way that if a mosquito lands on the net it will die. Even with a few holes, these are 90-95% effective according to the “Against Malaria Foundation” and only cost around $6 (US Dollars) including the distribution costs, whereas a full four doses of the potential malaria vaccine will be close to $20. The eradication of mosquitoes would certainly prove much more expensive that both of these methods.

The question remains of whether we should stay on the offense or defense when it comes to mosquito-transmitted malaria, and whether ethics should stop us from playing god with regard to scientific endeavour. I’ll leave that question up to you.

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