Average global temperatures are expected to rise by 5°C or more over the next century. That's a lot of heat to handle for thousands of plant and wildlife species that already have been affected by a seemingly paltry 0.60°C temperature change over the past century. Eggs hatch and flowers bloom earlier, and butterflies are shifting their ranges northward. Ecologists have gathered ample quantitative evidence that global warming changes the way animals eat, breed, and interact.1 But how and if they will evolve is another question altogether. Early findings suggest that evolution may depend on what organisms start out with genetically.
For some species, such as the Australian rainforest vinegar fly, Drosophila birchii, rapid climate changes may be too much for their genes to handle. Geneticist Ary Hoffmann and colleagues at La Trobe University, Melbourne, demonstrated that this moisture-dependent insect doesn't have the genetic variation needed to adapt to the arid ...
