本题目来源于试卷: Unity and Diversity A.8 Evolution and Speciation，类别为 IB生物学
[单选题]
Which of the following provides e 9ob:/biz 9lvl76vn mzvidence for evolution through selecti5vjwkh8/oq5x 2 t epr;fi4ku:ve breeding5x4h:5f p qvo /rk;utewj ik82?
I. Phenotypic variation in the domesticated dog (Canis familiaris) has increased significantly as a result of humans selecting desirable traits.
II. Crop yield in domesticated crop plants is significantly greater than their wild relatives.
III. Homo sapiens in many parts of the world have alleles that provide resistance to diseases endemic to their region.
A. I and II only
B. I and III only
C. III only
D. I, II and III
参考答案: A
本题详细解析:
Choice A is correct because statements I and II are correct. Statement I supports the theory of evolution because an increase in phenotypes is a component of the process of evolution. Statement II supports the theory of evolution because it exemplifies that humans, selecting for desirable traits, can cause directional selection in crop plants. Although statement III does support the theory of evolution, it does not do so as an example of selective breeding. Humans have not been selectively bred. Choices B, C and D do not exclusively include statements I and II, so they are incorrect.
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