>To what extent competition determines the composition of a community and the density of particular species has been the source of considerable controversy. The problem is that competition ordinarily cannot be observed directly but must be inferred from the spread of increase of one species and the concurrent reduction or disappearance of another species. The Russian biologist G.F Gause performed numerous two-species experiments in the laboratory, in which one of the species became extinct when only a single kind of resource was available. On the basis of these experiments and of field observations, the so-called law of competitive exclusion was formulated, according to which no two species can occupy the same niche. Numerous seeming exceptions to this law have since been found, but they can usually be explained as cases in which the two species, even though competing for a major joint resource, did not really occupy exactly the same niche.
Q22 Paragraph 3 supports the idea that Gause’s experiments were important because they
A. Provide a situation in which competition could be removed from the interaction between two species.
B. Showed that previous ideas about the extent to which competition determines the composition of a community were completely mistaken
C. Help establish that competition will remove all but one species from any given ecological niche.
D. Offered evidence that competition between species is minimal when these is an overabundance of a single food source.
答案是C
我选的B,因为文章首句是大概这个意思
虽然之后有路标On the basis of these experiments,但是感觉还是有点别扭。。。
求助大神们!
定位到这句话:
On the basis of these experiments and of field observations, the so-called law of competitive exclusion was formulated, according to which no two species can occupy the same niche.