Spider Web Decorations
An evolutionary puzzle is provided by orb-weaving spiders (weavers of round webs) that incorporate impressive zigzag lines of white ultraviolet silk into their webs. which would seem to make the trap more obvious to the prey that the spider needs to catch.Given that many insects can see ultraviolet light, one wonders how orb weavers could gain by alerting potential victims to the danger posed by their webs. But perhaps these web additions actually attract ultraviolet-reflecting bees that specialize in taking nectar from ultraviolet-reflecting flowers. The fact that bees constitute the large majority of prey of some spiders with ornamented webs supports this hypothesis.
完整版题目和答案请付费后查阅
