Fish story

Sticklebacks are cool. They demonstrate some extremely interesting behavior (more on that later) and have been the subject of some very significant research in ecology and evolution for decades. The threespine stickleback (Gasterosteus aculeatus) is essentially a marine fish, but many populations have been able to adapt to freshwater conditions. In Alaska, where populations have been landlocked by receding glaciers, they've evolved rapidly to adapt to their new environment. Changes in body armor, coloration, and behavior distinguish different populations. A new study appearing in PLoS Genetics attempts to get at the genetic basis of this adaptive process. Researchers compared genomes of five populations of sticklebacks, three from landlocked freshwater populations in coastal Alaska and two from nearby marine environments. The fish turned out to be very similar across most of their genomes, but proved to quite different in certain areas. What is particularly interesting is that the landlocked populations, independently derived, showed similar changes. This suggests that different populations are using the same genetic toolbox to solve the problems posed by their new freshwater habitats. The effort now is to identify the specific genes involved.