What Segs said:
Laser every mossie, and suddenly the world is overrun with giant, maneating zombie spiders laying waste our cities and driving humankind into mountain bunkers... where, within a generation, we will degrade into a society of gunwielding, check-wearing, murderous rednecks speaking with Arkansas twangs.
(Of course this scenario would be a revolutionary leap up the evolutionary scale for some areas: Luton, Birmingham and Deptford, S. London, being three Neanderthal locales that spring immediately to mind.)
Speaking of evolution:
Life finds a way.
Which means, Mr Darwin, that before we know it, we will be facing dive-bombing, laser-killing mosquitoes. Ho-hum - back to square one.