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 ratio has produced, in most plants and animals with separate sexes, approximately equal numbers of males an
The evolution of sex ratio has produced, in most plants and animals with separate sexes, approximately equal numbers of males an
admin
2010-05-25
62
问题
The evolution of sex ratio 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, and 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 incorporated 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 strategy.
What can we know about the scientists Fisher and Hamilton from the passage?
选项
A、They both made contribution to the mathematical theory of games.
B、They both sought an explanation of why certain sex ratios exist and remain stable
C、The former stressed the maximization and the latter emphasized the optimization.
D、They both inherited the insight of the "group, selection" argument.
答案
B
解析
事实细节题。考查Fisher和Hamilton的两个论点的共性,选项A 和D 不符合文章意思,选项 C 是干扰项,从第一段第五句话我们知道最大化是集体选择论的观点。实际上Fisher和Hamilton都认同最优化。选项B 正确。Fisher的观点在第一段第九句集中体现,Hamilton此观点与Fisher的相似性在文章最后一句得到体现。
转载请注明原文地址:https://kaotiyun.com/show/Fw2K777K
0
专业英语四级
相关试题推荐
Wehaddifficultiesatfirstbuteverythingworked______smoothlyintheend.
Ofallthingsintheworld,Imostdislikefillingupforms;infact,Ihaveapositivehorrorofit.Applyingforadrivinglic
Whetherornotanimalsfeelisnotaltogetheraneasyquestiontoanswer.Ahumanbeinghasdirectawarenessonlyofthepainsw
Mostchildrenwithhealthyappetitesarereadytoeatalmostanythingthatisofferedtothemandachildrarelydislikesfood【
Mostchildrenwithhealthyappetitesarereadytoeatalmostanythingthatisofferedtothemandachildrarelydislikesfood【
【C1】______snakes,lizards,andcrocodiles,turtlesbelongtotheclassofanimalscalledreptiles.Theearliestfossilsrecogni
Ihavenochoicethenbut______moneyfrommysister-in-law.
Miro,AJustManMirowasgoodness,ajustmaninallthings.Hedidnotspeakmuchbutwasverycourteous.Ineversawhimwith
Youshouldtakeanumbrellawithyou___________itrains.
随机试题
计划工作,就是根据实际情况,提出未来一定时期内组织所要达到的目标及实现目标的方法,具体内容包括()
二陈汤治疗“寒痰”,《医方集解》加减法中指明应加用的药物是
A.声哑,犬吠样咳嗽,双肺呼吸音清B.吞咽疼痛,流涎,说话似口中含物C.声哑,痰中带血丝,纤维喉镜下声带菜花状新生物D.阵发性咳嗽,一侧肺呼吸音较对侧明显弱,胸透可见纵隔摆动E.吞咽疼痛,声音嘶哑,棉絮钡餐透视可钡剂残留
下列何经直接通于脑()
按照我国现行企业财产保险条款的规定,( )不属于不可保财产。
【2015.辽宁特岗】教师职业道德
根据资料,回答下列问题。2010年,江苏省全年粮食总产量达3235.1万吨,比上年增加5万吨;其中夏粮1105.3万吨,增长0.2%;秋粮2129.8万吨,增长0.1%。全年粮食面积为528.2万公顷,比上年增加1.0万公顷;棉花面积为23.6万
WFP
有关个人价值和社会价值的关系,错误的观点是
舞蹈是“美”的【C1】______,是人类最古老的艺术形式之一。它经过美化的人体动作,有组织、有韵律地手舞足蹈,抒发感情,表达意愿,是形象地【C2】______社会生活的一门独立的艺术。舞蹈源于生活。人类在劳动斗争中解放了手和脚,为舞蹈的产生【C
最新回复
(
0
)