评论
打印
Although it is intuitively clear that an increase in antipredator behavior lowers an animal's risk of predation when predators are present,such benefits are not easily demonstrated. One study that did so found that well-fed guppies are more alert for predators and are consequently less likely to be killed than are their hungry counterparts, which feed with greater intensity. It is also well documented that a decrease in activity lowers an animal's risk of predation by reducing the probability of being detected or encountered by a predator. This effect was convincingly demonstrated by a study in which it was found that partially anesthetized tadpoles were less likely to be captured by dragonfly larvae than were unanesthetized tadpoles.
It can be inferred that the guppy study and the tadpole study, as they are described in the passage, differed in which of the following ways?
A.The animals less likely to become the victims of predators were the more active ones in the guppy study but were the less active ones in the tadpole study.
B.The animals less likely to become the victims of predators were those more alert to their surroundings in the guppy study but were the less alert ones in the tadpole study.
C.The situation created experimentally for the guppy study would be more likely to occur in the wild than would the situation created for the tadpole study.
In the context indicated, “demonstrated” (line 3) most nearly means
A.explained
B.presented
C.shown
D.protested
E.justified105
