In 2005, the genome sequence of a mosquito enabled researchers to take a close look at how speciation might occur among populations that can still interbreed. They discovered that two populations of the mosquito that might be separating into separate species had just a few DNA differences, which they called "genomic islands of speciation." This set off a stampede of other researchers looking for—and finding—genomic islands in other species on the verge of splitting. But other work suggested these islands were statistical artifacts, leading one of the creators of the island concept to renounce the idea. Still, recent work in crows, sunflowers, and stick insects continues to build the case for these islands.