Mosquitoes are the biggest killers for one reason, they can transport the deadly pathogen malaria when they bite a human. Geneticists have been trying to "enhance" the gene of mosquitoes to be resistant to strains of malaria in order to prevent its transportation. The problem with this method is that, even with a working gene in mosquitoes, there is only a 50% chance it will be passed on to offspring. Enter gene drives, the revolutionary new technique that could make worrying about gene inheritance a thing of the past.
Gene drives by damaging a non coding area in a chromosome with a gene editing tool called CRISPR/CAS9. The damaged area in a chromosome is then repaired by the cell, but this time it is CRISPR/CAS9 repairs the damaged area with the malaria resistant gene. At this point there are now two spots on mosquitoes's chromosome that have the malaria resistance gene, and there for it is twice as likely to be carried on. And this process can be repeated until there is a 99.9% chance that the gene will be passed on.
To me this is a great discovery, not just for helping in the eradication of malaria, but also many other potential environmental factors as well, such as the elimination of invasive species, or even making an endangered species more environmentally apt to not dying out.