首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
The evolution of sex ratios has produced, in most plants and animals with separate sexes, approximately equal numbers of males a
The evolution of sex ratios has produced, in most plants and animals with separate sexes, approximately equal numbers of males a
admin
2020-03-30
55
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.
It can be inferred from the passage that the mathematical theory of games has been______.
选项
A、developed by scientists with an interest in genetics
B、useful in explaining some biological phenomena
C、adopted by Hamilton in his research
D、based on animal studies conducted prior to 1930
答案
B
解析
本题考查的是对文章的综合理解。B项“在解释生物学现象方面有用”是最佳答案。
转载请注明原文地址:https://kaotiyun.com/show/G1TO777K
0
考博英语
相关试题推荐
Ateacherissomeonewhocommunicatesinformationorskillsothatsomeoneelsemaylearn.Parentsarethe【C1】______teachers.Ju
It’sallannualback-to-schoolroutine.Onemorningyouwavegoodbye,andthat【C1】______eveningyou’reburningthelate-nightoi
Thebedhasbeen______inthefamily.Itwasmygreatgrandmother’soriginally.
Mr.Abu,thelaboratoryattendant,cameinfromtheadjoiningstoreandbrisklycleanedtheblackboard.HewasaretiredAfrican
InMicrosoft’slatestattempttoreachouttobloggers,thecompanyrecentlygaveawayexpensivelaptopsloaded【C1】______itsnew
WhentheAconcentrationofcalciuminthebloodisBtoolow,theparathyroidglandsCbegantoDsecretethehormoneparathormone.
Comparisonsweredrawnbetweenthedevelopmentoftelevisioninthe20thcenturyandthediffusionofprintinginthe15thand
Althougharchitecturehasartisticqualities,itmustalsosatisfyanumberofimportantpractical______.
Wearegovernedbythehormonesthat______aroundourbodies.
Biologymaynotbedestiny,butgenesapparentlyhaveafargreaterinfluenceonhumanbehaviorthaniscommonlythought.Simila
随机试题
下列关于期权市场标的物市场价格和执行价格的说法,正确的是()。
一块由标准盐酸饱和后的岩心,用标准盐水驱替时,测其岩心的渗透率是1.63×10-3μm2,经15%盐酸溶液酸化后,再用标准盐水驱替时,测其岩心的渗透率是0.98×10-3μm2,求该岩心的酸敏指数。
医师和药学专业技术人员在药物临床应用时必须遵循的原则是
患者,女,12岁。因颈部包块来院就诊,经认真检查确诊为甲状腺癌,并有颈淋巴结转移。经周密考虑,医师建议使用改进型甲状腺根治术。有文献报道效果较好,术后不会出现身体外观的明显改变。但本院只有2名医师学习过该手术,本院尚未开展此手术,手术成功的把握较小。根据以
某市一商贸企业2019年末建成办公楼一栋,为建造办公楼新征一块土地,面积为45000平方米,土地单价为每平方米300元,房产建筑面积为20000平方米,建筑成本为2000万元。该办公楼使用年限为50年,计算该办公楼原值()万元。
中国游客成为世界“金主”“土豪”疯狂购物的新闻_________,世界各国商业街专门挂出中文路标、配备中国导购更是________。可是,在美国地面上升国旗、唱国歌、大合影、狂购物,样样出新、件件破格_________。如果把它归结成一场简单的爱国之旅,疯
欧洲煤钢联营协定
BGP路由选择协议的四种分组中不包括()。
在考生文件夹下有一个数据库文件“samp2.aecdb”,其中存在已经设计好的3个关联表对象“tCourse”、“tGrade”、“tStudent”和一个空表“tSinfo”,请按以下要求完成设计。创建一个查询,查找年龄小于平均年龄的学生,并显示其“
【B1】【B17】
最新回复
(
0
)