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
68
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
Fromthepassage,whydidthePilgrimssailtoAmerica?[br]Whydidpeopledeci
Mariabecameincreasingly________,soshefledtoherhometowninAustria.A、hast
Theyoungwasquestioned__________(当着一大群人的面).inthepresenceofalargenumbe
导致子宫脱垂的最主要原因是A.多产 B.先天发育不良 C.缺乏雌激素 D.
2001年3月7日16时20分左右,三门峡灵宝市义寺山金矿五坑发生特大CO中毒事
关于分级资产管理产品的说法中,错误的是()。A.公募产品和开放式私募产品不得进
共用题干 第一篇HumanEvolutionBeingamanhas
社会工作者严戈为某社区的低保家庭成员开展了一系列小组活动,活动结束时很多组员都对
根据相关法律规定,下列建设工程项目实行强制监理的有()。A、项目总投资额在300
架空线路施工时,下列说法正确的有()。A.螺栓紧固后,单螺母螺杆丝扣露出的不应少
最新回复
(
0
)