Deeper Still And Deeper

摘要

Darwin suggested that particularly long-tongued pollinators and long-tubed fiowers are dancers in a sort of coevolutionary tango, each acting as selection pressure on the other. When faced with a flower that keeps its nectar at the end of a long tube, a nectar bat (Anoura fistulata, pictured) with a longer-than-average tongue hasrnan advantage over its shorter-tongued conspecifics. Now, Nathan Muchhala and James Thomson of the University of Toronto, Canada, have shown that pressures run the other way as well.