首页
登录
职称英语
The evolution of sex ratios has produced, in most plants and animals with sep
The evolution of sex ratios has produced, in most plants and animals with sep
游客
2023-12-11
50
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 grand children. 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 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. [br] According to the passage, successful game strategy depends on______.
选项
A、the ability to adjust one’s behavior in light of the behavior of others
B、one’s awareness that there is safety in numbers
C、the degree of stability one can create in one’s immediate environment
D、the accuracy with which one can predict future events
答案
A
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3263627.html
相关试题推荐
FiveTipsforStudyingAmericanRevolutionAmericanRevolution—
FiveTipsforStudyingAmericanRevolutionAmericanRevolution—
FiveTipsforStudyingAmericanRevolutionAmericanRevolution—
FiveTipsforStudyingAmericanRevolutionAmericanRevolution—
FiveTipsforStudyingAmericanRevolutionAmericanRevolution—
WhendidtheEnglishBourgeoisRevolutiontakeplace?A、In1640.B、In1641.C、In
HowDeerSurviveWinterLikemostofthewildanimals,deersurviv
HowDeerSurviveWinterLikemostofthewildanimals,deersurviv
HowDeerSurviveWinterLikemostofthewildanimals,deersurviv
HowDeerSurviveWinterLikemostofthewildanimals,deersurviv
随机试题
Iwanttomakeuseofthisshortgatheringtomakeclearourworkingrequirem
[originaltext]M:Howdoyoulikethebook?[/originaltext][audioFiles]2021m8x/a
A.缓起低热、乏力、盗汗、纳差、干咳,体重下降 B.发热,咳嗽,咳大量脓痰,间
产后出血的病因可分为_____________、_____________、__
下列各项中,不符合内部牵制的要求的是()。A、出纳人员管票据 B、出纳人员
解肌清热的方剂是A.加减葳蕤汤B.桂枝汤C.香薷散D.柴葛解肌汤E.升麻葛根汤
共用题干 TravelAcrossAfricaForsixhours
烧伤后体液渗出的高峰期是()。A.伤后2~3小时 B.伤后4~6小时 C.
下边四个图形中,只有一个是由上边的四个图形拼合(只能通过上、下、左、右平移)而成
高老病逝,生有二子高大、高二,领养一子高三,高老的妻子尚在。他留有保险金额24万
最新回复
(
0
)