首页
登录
职称英语
The evolution of sex ratios has produced, in most plants and animals with se
The evolution of sex ratios has produced, in most plants and animals with se
游客
2025-04-05
0
管理
问题
The evolution of sex ratios has produced, in most plants and animals with separate sexes, approximately equal numbers of males and females. Why should this be so? Two main kinds of answers have been offered. One is couched in terms of advantage to population. It is argued that the sex ratio will evolve so as to maximize the number of meetings between individuals of the opposite sex. This is essentially a " group selection" argument. The other, and in my view correct, type of answer was first put forward by Fisher in 1930. This "genetic" argument starts from the assumption that genes can influence the relative numbers of male and female offspring produced by an individual carrying the genes. That sex ratio will be favored which maximizes the number of descendants an individual will have and hence the number of gene copies transmitted. Suppose that the population consisted mostly of females, then an individual who produced sons only would have more grandchildren. In contrast, if the population consisted mostly of males, it would pay to have daughters. If, however, the population consisted of equal numbers of males and females, sons and daughters would be equally valuable. Thus a one-to-one sex ratio is the only stable ratio; it is an "evolutionarily stable strategy. " Although Fisher wrote before the mathematical theory of games had been developed, his theory incorporates the essential feature of a game that the best strategy to adopt depends on what others are doing.
Since Fisher’s time, it has been realized that genes can sometimes influence the chromosome or gamete in which they find themselves so that the gamete will be more likely to participate in fertilization. If such a gene occurs on a sex-determining(X or Y)chromosome, then highly aberrant sex ratios can occur. But more 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 argument, it should still 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 eggs in a given larva, it would pay her to produce one male only, because this one 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. [br] It can be inferred from the passage that the author considers Fisher’s work to be______.
选项
A、definitive and thorough
B、inaccurate but popular, compared with Hamilton’s work
C、accurate, but trivial compared with Hamilton’s work
D、admirable, but not as up-to-date as Hamilton’s work
答案
D
解析
本题中,A、B、C三项都与文章的意思不符。综观全文,可知作者支持Fisher的观点,但Hamilton的观点更新。因此D项为正确答案。
转载请注明原文地址:https://tihaiku.com/zcyy/4027374.html
相关试题推荐
InDisneyland,everyyear,some800,000plantsarereplacedbecauseDisneyrefus
AtleastsincetheIndustrialRevolution,genderroleshavebeeninastate
AtleastsincetheIndustrialRevolution,genderroleshavebeeninastate
AtleastsincetheIndustrialRevolution,genderroleshavebeeninastate
AtleastsincetheIndustrialRevolution,genderroleshavebeeninastate
AtleastsincetheIndustrialRevolution,genderroleshavebeeninastate
AtleastsincetheIndustrialRevolution,genderroleshavebeeninastate
AtleastsincetheIndustrialRevolution,genderroleshavebeeninastate
AtleastsincetheIndustrialRevolution,genderroleshavebeeninastate
Theearthiswitnessinganurbanrevolution,aspeopleworldwidecrowdinto
随机试题
主动脉瓣狭窄杂音的特点是()A.胸骨右缘第2肋间收缩期喷射性杂音 B.胸骨左缘
A.当X2不变时,X1每变动一个单位Y的平均变动。 B.当X1不变时,X2每变
A.杞菊地黄汤加减 B.小半夏加茯苓汤加减 C.五皮饮合五苓散加减 D.参
小儿头围与胸围两者几乎相等的年龄是A.3个月 B.5个月 C.9个月 D.
请简要阐述教育史上关于教育的起源的三种主张。
在选择绩效考核方法时,如下选项不属于应考虑的因素的是( )。A.工作实用性
2012年底,某制衣厂有一笔服装加工业务被无证个体户屠某以42万元承包,屠
属于桥梁伸缩缝病害原因的有()。A.交通流量偏小 B.将伸缩缝的预埋钢筋
空调系统冷凝水管道宜采用的管材为()。A.聚氯乙烯塑料管 B.橡胶管
知识点:糖皮质激素 糖皮质激素类药物可明显减少 A.中性粒细胞 B.淋巴细
最新回复
(
0
)