GRE閱讀題目解析:寄生性胡蜂種群

　　GRE閱讀題目解析:寄生性胡蜂種群

　　P1

　　Questions 1 to 3 are based on the following reading passage.

　　Immediately relevant to game theory are the sex ratios in certain parasitic wasp species that have a large excess of females. In these species, fertilized eggs develop into females and unfertilized eggs into males. A female stores sperm and can determine the sex of each egg she lays by fertilizing it or leaving it unfertilized. By Fisher‘s genetic argument that the sex ratio will be favored which maximizes the number of descendants an individual will have and hence the number of gene copies transmitted, it should pay a female to produce equal numbers of sons and daughters. Hamilton, noting that the eggs develop within their host—the larva of another insect—and that the newly emerged adult wasps mate immediately and disperse, offered a remarkably cogent analysis. Since only one female usually lays eggs in a given larva, it would pay her to produce one male only, because this one male could fertilize all his sisters on emergence. Like Fisher, Hamilton looked for an evolutionarily stable strategy, but he went a step further in recognizing that he was looking for a strategy.

　　1. The author suggests that the work of Fisher and Hamilton was similar in that both scientists

　　(A) conducted their research at approximately the same time

　　(B) sought to manipulate the sex ratios of some of the animals they studied

　　(C) sought an explanation of why certain sex ratios exist and remain stable

　　(D) studied game theory, thereby providing important groundwork for the later development of strategy theory

　　(E) studied reproduction in the same animal species

　　(For the following question, consider each of the choices separately and select all that apply)

　　2. The passage contains information that would answer which of the following questions about wasps?

　　A How many eggs does the female wasp usually lay in a single host larva?

　　B Can some species of wasp determine sex ratios among their offspring?

　　C What is the approximate sex ratio among the offspring of parasitic wasps?

　　3. Which of the following is NOT true of the species of parasitic wasps discussed in the passage?

　　A) Adult female wasps are capable of storing sperm.

　　B) Female wasps lay their eggs in the larvae of other insects.

　　C) The adult female wasp can be fertilized by a male that was hatched in the same larva as herself.

　　D) So few male wasps are produced that extinction is almost certain.

　　E) Male wasps do not emerge from their hosts until they reach sexual maturity.

　　P1

　　1

　　Immediately relevant to game theory are the sex ratios in certain parasitic wasp species that have a large excess of females.

　　某些寄生性胡蜂種群內(nèi)雌性的數(shù)量遠(yuǎn)超雄性，這種性別比與博弈論緊密相關(guān)。

　　(game theory：博弈論)

　　2

　　In these species, fertilized eggs develop into females and unfertilized eggs into males.

　　在這些種群內(nèi)，受精卵發(fā)育為雌蜂，而未受精卵發(fā)育為雄蜂。

　　3

　　A female stores sperm and can determine the sex of each egg she lays by fertilizing it or leaving it unfertilized.

　　雌蜂攜帶精子，能夠通過選擇是否讓其受精，來決定它產(chǎn)的每一枚卵的性別。

　　4

　　By Fisher‘s genetic argument that the sex ratio will be favored which maximizes the number of descendants an individual will have and hence the number of gene copies transmitted, it should pay a female to produce equal numbers of sons and daughters.

　　F 的遺傳學(xué)觀點(diǎn)認(rèn)為，讓每一個(gè)體產(chǎn)生最多后代，且因此(最大程度)傳播自身基因的性別比，最具競爭優(yōu)勢(shì)，生育數(shù)量相當(dāng)?shù)膬煞N性別的后代，對(duì)雌蜂是最有利的。

　　(pay 【MWC】to return value or profit to 回報(bào)…，有利于…)

　　5

　　Hamilton, noting that the eggs develop within their host — the larva of another insect — and that the newly emerged adult wasps mate immediately and disperse, offered a remarkably cogent analysis.

　　注意到卵都在宿主體內(nèi) —— 另一種昆蟲的幼蟲 —— 發(fā)育，而且新生的蜂成熟后立刻交配并離開，H 提出了一種相當(dāng)有說服力的分析。

　　6

　　Since only one female usually lays eggs in a given larva, it would pay her to produce one male only, because this one male could fertilize all his sisters on emergence.

　　既然每只被寄生的幼蟲里只有一只雌蜂產(chǎn)卵，則只生產(chǎn)一只雄蜂最有利，因?yàn)檫@只雄蜂已經(jīng)足夠?yàn)樗械慕忝锰峁┚印?/p>

　　7

　　Like Fisher,Hamilton looked for an evolutionarily stable strategy, but he went a step further in recognizing that he was looking for a strategy.

　　H 和 F 都尋找一種進(jìn)化論意義上的穩(wěn)定策略，但 H 更進(jìn)一步，他意識(shí)到自己在尋找這樣一種策略。

　　1. The author suggests that the work of Fisher and Hamilton was similar in that both scientists

　　(A) conducted their research at approximately the same time

　　(B) sought to manipulate the sex ratios of some of the animals they studied

　　(C) sought an explanation of why certain sex ratios exist and remain stable

　　(D) studied game theory, thereby providing important groundwork for the late development of strategy theory

　　(E) studied reproduction in the same animal species

　　選 C

　　根據(jù)句 7：

　　Like Fisher,Hamilton looked for an evolutionarily stable strategy, but he went a step further in recognizing that he was looking for a strategy.

　　所以選 C，“他們都嘗試解釋為什么這些寄生蜂種群內(nèi)有特定的性別比，且能保持這個(gè)比例穩(wěn)定。”

　　A 未知。

　　B 錯(cuò)在 manipulate 。

　　D 說反了，應(yīng)該說他們都試圖用博弈論來解釋同一種科學(xué)發(fā)現(xiàn)。

　　E 這項(xiàng)沒什么錯(cuò)，但顯然不是最佳答案，正如我們不應(yīng)該把 “他們都是人” 或 “他們都是科學(xué)家” 作為他們的共同點(diǎn)一樣。

　　For the following question, consider each of the choices separately and select all that apply

　　2. The passage contains information that would answer which of the following questions about wasps?

　　A How many eggs does the female wasp usually lay in a single host larva?

　　B Can some species of wasp determine sex ratios among their offspring?

　　C What is the approximate sex ratio among the offspring of parasitic wasps?

　　不定項(xiàng)選擇，有時(shí)候真的會(huì)選3個(gè)。

　　選 B

　　A 未知信息。

　　B 根據(jù)句 3：

　　A female stores sperm and can determine the sex of each egg she lays by fertilizing it or leaving it unfertilized.

　　C 我們知道一個(gè)寄主內(nèi)有一只雄蜂，但不知道寄主內(nèi)雌蜂的數(shù)量，所以不能確定性別比。

　　3. Which of the following is NOT true of the species of parasitic wasps discussed in the passage?

　　(A) Adult female wasps are capable of storing sperm.

　　(B) Female wasps lay their eggs in the larva of other insects.

　　(C) The adult female wasp can be fertilized by a male that was hatched in the same larva as herself.

　　(D) So few male wasps are produced that extinction is almost certain.

　　(E) Male wasps do not emerge from their hosts until they reach sexual maturity.

　　選 D

　　A

　　句 3：

　　A female stores sperm and can determine the sex of each egg she lays by fertilizing it or leaving it unfertilized.

　　B

　　句 5：

　　…… within their host — the larva of another insect — and that ……

　　C

　　句 6：

　　Since only one female usually lays eggs in a given larva, it would pay her to produce one male only, because this one male could fertilize all his sisters on emergence.

　　D

　　… extinction is almost certain，一看就廢了。

　　E

　　句 5：

　　… newly emerged adult wasps mate immediately and disperse …