Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions.
Butterflies are among the most extensively studied insects – an estimated 90 percent of the world’s species have scientific names. As a consequence, they are perhaps the best group of insects for examining patterns of terrestrial biotic diversity and distribution. Butterflies also have a favorable image with the general public. Hence, they are an excellent group for communicating information on science and conservation issues such as diversity.
Perhaps the aspect of butterfly diversity that has received the most attention over the past century is the striking difference in species richness between tropical and temperate regions.
For example, in 1875 one biologist pointed out the diversity of butterflies in the Amazon when he mentioned that about 700 species were found within an hour’s walk, whereas the total number found on the British islands did not exceed 66, and the whole of Europe supported only 321. This early comparison of tropical and temperate butterfly richness has been well confirmed.
A general theory of diversity would have to predict not only this difference between temperate and tropical zones, but also patterns within each region, and how these patterns very among different animal and plant groups. However, for butterflies, variation of species richness within temperate or tropical regions, rather than between them, is poorly understood. Indeed, comparisons of numbers of species among the Amazon basin, tropical Asia, and Africa are still mostly “personal communication” citations, even for vertebrates. In other words, unlike comparison between temperate and tropical areas, these patterns are still in the documentation phase.
In documenting geographical variation in butterfly diversity, some arbitrary, practical decisions are made. Diversity, number of species, and species richness are used synonymously; little is known about the evenness of butterfly distribution. The New World butterflies make up the preponderance of example because they are the most familiar species. It is hoped that by focusing on them, the errors generated by imperfect and incomplete taxonomy will be minimized.
All of the following are mentioned as being important parts of a general theory of diversity EXCEPT _______.
A. differences between temperate and tropical zones
B. patterns of distribution of species in each region
C. migration among temperate and tropical zones
D. variation of patterns of distribution of species among different animals and plants
Đáp án C.
Key words: important parts, general theory, EXCEPT.
Clue: “A general theory of diversity would have to predict not only this difference between temperate and tropical zones, but also patterns within each region, and how these patterns vary among different animal and plant groups”: Một lý thuyết tổng quát về sự đa dạng đã phải dự đoán được không chỉ sự khác biệt giữa các khu vực ôn đới và nhiệt đới mà còn các kiểu mẫu theo từng vùng và sự biến đổi của những kiểu mầu giữa các nhóm động thực vật khác nhau.
Cấu trúc “not only… but also…” (không những … mà còn…) đã đưa ra ba phần quan trọng của lý thuyết này. Trong đó không đề cập đến “migration among temperate and tropical zones”: sự di cư giữa các vùng ôn đới và nhiệt đới. Vậy đáp án C là phù hợp nhất.