This past week we discussed germ governance as well as
vectors (go Team Love on listing so many vectors!). I think we are all very familiar with, and don’t
have to look in our articles to name, a particular vector - mosquitoes. Mosquitoes bite us, they are present nearly
globally, and they carry and transmit disease.
Do they do any good? Not
really. We should just get rid of them. “But wait, what about the environment and the
ecosystem?!” There are many species of
mosquitoes, but only a few bite and transmit disease. So killing just these species would have a
small impact, if any, on the environment and a huge impact on human health. What if we killed all of the mosquitoes? Okay, less radically, what if scientists could
find a way to genetically disturb the breeding process, so that female
mosquitoes could no longer be born (remember – females are the only ones that
bite)? An NPR Radio Lab podcast and BBC
article discusses…
Diseases caused by mosquitoes kill around one million
people a year and bring illness to more than 500 million. Only the female mosquitoes of certain species
bite, and do so because human blood is full of protein for them to produce
eggs. It is very dangerous for these
ladies to bite humans because it is so easy for us to kill them, but they must
to survive. In terms of burden, some
estimates have placed the number of deaths due to mosquito-borne diseases to be
greater than that of heart disease and cancer.
So clearly, mosquitoes are a big problem to humans.
Most people may agree that mosquitoes are bad, but even
if everyone did agree it would be near impossible to eliminate them using
conventional methods (pesticides, etc.) because mosquitoes are incredibly fertile. This strength could be used against them… In
Brazil, there is a “mosquito factory” where researchers and engineers breed
mosquitoes in the effort to genetically modify them to carry a lethal
gene. This gene is turned off and placed
in males. This gene is then passed on to
females’ eggs where it will turn on. When
turned on, the gene creates a protein that eventually destroys the mosquito. This genetic modification has already been
put into place in certain places in Brazil to prevent dengue fever; in six
months, the mosquito population was reduced by 96% and reduced the population
even into the next season, greatly reducing incidence of dengue fever.
Obviously this is quite a radical solution… Are there any
redeeming factors to the mosquito? What
if we kill them all? What if we don’t kill
them all? What would be the global
impact? Are there any ethical
considerations to this? The article and
podcast answered some of these, but I am curious to see what you all come up
with!
References:
Lisa, this is a very provocative post scientifically. Prof. Catherine Hill raised this in a seminar the other day and did not provide a definite answer. I am struggling for one too!! You see life is so beautiful and living organisms and so inter-related with each other. We never know the eventual "unintended" consequences of our action down the line in nature. Attaching another excellent piece to provide you with an answer or maybe not!!
ReplyDeletehttp://www.nature.com/news/2010/100721/full/466432a.html
Lisa & Lala,
ReplyDeleteThis is certainly a heavy and sensitive topic and angle! And you are right, we don't know the consequences of our actions and I also believe we have the moral right not to "play god" with any creature, living or dieing. As this is so, science has certainly attempted to in many ways more than one other than the mosquito. But perhaps these research funds on attempting to find a way to eliminate the female mosquitoes should be put to prevention of the disease such as in health systems to distribute bed nets or overcoming challenges in distribution systems found in landlocked countries. How will the species repopulate? This for me, brings on the same moral issue of hunting as sport and on endangered species. Genetically modified or not, I don't think we have that right to determine who gets to live and who gets to die. Does this mean we are valuing one living being's life over another? Perhaps another solution should come from redistributing our system so that those who do suffer from such an illness can be provided with the same treatments as someone in a more wealthy country.
I think the efforts and energy should be put on prevention in other ways without harming an entire species. We as humans don't have this right and again, this could also just be the very thing that creates another domino effect on something far worse than malaria!
Lisa, I have always thought that mosquitoes are the most useless nuisance we have in the animal kingdom. All they do is spread disease and mayhem. Unlike other unsavory creatures like snakes and spiders, mosquitoes do not really have an obvious purpose. Snakes keep down the numbers of vermin in the world. Spiders do the same for bugs. Maybe the mosquito’s purpose is to control the human population. As morbid a thought as that is, it is the only reason I can think that mosquitoes continue to exist. At the health department this summer we sprayed an adulticide to try and control the numbers of humans bit and infected. Unfortunately, this type of pesticide just kills the adult mosquitoes flying around at that time. Larvicide dunks are slightly more proficient in preventing the little buggers from being born. The future of mosquito control (and hopefully elimination of the disease vectors) will improve in the coming years.
ReplyDeleteErin, seeing mosquitoes as a method to control the human population is quite a radical and controversial view! But I like how you have placed us within the ecosystem. I feel like we tend to separate humans and environment, thinking that we are some external factor imposing our dominance over a beautiful natural ecosystem, but realistically if we want to make progress on environmental issues, including how we should interact with species like mosquitoes, we really have to see ourselves as a key player WITHIN the environment rather than an outside influence. Your point also brings up a huge ethical issue that may be beyond the scope of this class, but are we kidding ourselves to think we can control all disease threats? Is there some sort of environmental control in place on our planet that will keep presenting us with bigger and bigger threats as we keep striking them down? Thanks for making me think!
ReplyDelete