Wednesday, August 12, 2015

Modifying a Mosquito

   Photo by Muhammad Mahdi Karim/Wikipedia,
Sitting on the deck above the creek, swatting mosquito's, it is easy to wish for a scientific breakthrough that would eliminate all mosquitoes or at least modify them so they didn't transmit disease.  It looks like some of this could occur during our lifetime but an article from Scientific American reminds us to be careful what we wish for.

Scientists now have the ability to "edit" genes in insects.  Not only are there techniques that might someday prevent a mosquito from carrying malaria, but there are techniques that could potentially expand a given mutation throughout the whole population of insects.  Sounds good so far.

Then we come to the Pandora's Box effect.  Suppose an altered species escapes the lab before we know all the consequences of the mutation.  In new pharmaceuticals, the benefits are proven long before all the side effects emerge when a drug is used by a much larger number of people.  And this is in a case where we can stop prescribing the drug to limit the damage to a small group of humans.  When you consider altering species in the wild, the effects on the food chain, predator-prey relations, and the spread to related species, the consequences become really scary.
Yellow fever vector Aedes aegypti -Photo by Muhammad Mahdi Karim
Consider for a moment a gene that could stop female mosquitoes from biting us.  One that could spread through the whole world-wide mosquito population.  Since they require blood of humans or "lesser species" of mammals -insert your own definition here- the entire mosquito population conceivably go extinct.  However there are over 3,500 species world wide, most of which pose no danger of disease or even of biting us.  They are food for insects up and down the food chain, although no one species is dependent upon them.  Some are even incidental pollinators!

Then there is the risk of a genetic mutation that could jump to other species.  It only gets more speculative (and more scary) from here.  Way too many unknowns.

The Scientific American article emphasizes the need for fool-proof containment of the modified insects to the lab until we know all the ramifications of their future release.  Unfortunately we are unlikely to know all the risks for years after a release and our ability to secure labs has been dicey to say the least.  Remember that even recently government labs accidentally distributed live anthrax to nine different locations, and this was in from a highly secure facility.  There are no easy answers.

Thanks to "Daddy-Dave" Shanholtzer for the lead.

1 comment:

  1. It's been a good year (no so good for humans) for Asian Tiger mosquitos in the Ozarks. It's a cousin of the one pictured above and sports black and white bands on legs and thorax. Despite efforts to eliminate standing water, these buggers can reproduce with only 1/4 inch of water, and frequently use natural wet leaf layers and water in tree holes. It's the first year they've appeared in our backyard. Suddenly, husband Charley, gets big red, itchy welts.