Sunday, February 28, 2010


This morning I read a short blurb in the local newspaper reporting recent progress by scientists in genetically altering the Aedes aegypti to suppress the development of wings in the females. The modification would be spread through the males (whose wings are unaffected), eventually wiping out the mosquitoes, providing a cheaper, more environmentally friendly and equitable method of control than chemical sprays.

I have no soft spot for those female Aedes aegypti. They are the vectors of dengue fever, a horrible experience for the 50 million people who come down with it every year (and one that is sometimes fatal, especially for children). Two-fifths of the world's population is at risk (mostly in Southeast Asia and Africa) and there is no vaccine and no treatment.

So getting rid of this mosquito is a good thing, right?

The more I learn about the natural world and the intricate connections in ecosystems, the more hesitant I am to say "yes". More often than not when it comes to making drastic changes to any environment or population, intervention tends to beget more intervention. Dam a river for flood control and then spend decades and millions of dollars trying to restore local fish populations and prevent downstream beaches from eroding, only to realize that the sediment building up behind your dam will eventually force it to give way (resulting in a flood far more catastrophic than any the dam prevented). Refine wheat to create a whiter, "tastier" bread, only to find that the most important nutrients were in the parts of the grain removed during refining, and then spend millions figuring out how to fortify flour with the nutrients you removed (and come up with something as absurd as whole wheat white flour). Get rid of the pigs in your garbage dumps to prevent the spread of swine flu and then realize the huge volume of waste they disposed of and have a trash problem to deal with. Eradicate Aedes aegypti and...who knows? The question of intervention gets even more complicated when you consider the prior interventions that made these things necessary (settling on flood plains, creating cultures of waste, heating up the planet and expanding the habitats of disease vectors like Aedes aegypti). Are we so locked into patterns of working against nature (poison all the insects in a field) rather than with it (planting habitat for beneficial insect populations) that we can't stop the cycle of intervening?


  1. Hmmm, that's definitely interesting about the Aedes aegypti. I think I agree with you Sarah. Intervention (in many different ways) often seems to happen without much real for thought about the broader implications. Do you know if the modification is something that will definitely move forward?