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
2025-04-21
33
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 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、the degree of stability one can create in one’s immediate environment
C、the accuracy with which one can predict future events
D、the success one achieves in conserving and storing one’s resources
答案
A
解析
转载请注明原文地址:https://tihaiku.com/zcyy/4047911.html
相关试题推荐
Thediversityoftropicalplantsintheregionrepresentsaseemingly______sou
Theearthiswitnessinganurbanrevolution,aspeopleworldwidecrowdinto
Theearthiswitnessinganurbanrevolution,aspeopleworldwidecrowdinto
Extraordinarycreativeactivityhasbeencharacterizedasrevolutionary,fly
Extraordinarycreativeactivityhasbeencharacterizedasrevolutionary,fly
AtleastsincetheIndustrialRevolution,genderroleshavebeeninastate
AtleastsincetheIndustrialRevolution,genderroleshavebeeninastate
AtleastsincetheIndustrialRevolution,genderroleshavebeeninastate
AtleastsincetheIndustrialRevolution,genderroleshavebeeninastate
AtleastsincetheIndustrialRevolution,genderroleshavebeeninastate
随机试题
Ihatedriving.Ihatethetraffic,theconfusingdesignofhighwaysinmyc
Hefinished______schoolattheageofeighteen.A、aB、theC、thisD、/D有些个体名词,加零冠词
患者女性,54岁,腋下可触及肿块,皮色不变,灼热疼痛,上肢活动不利,伴恶寒发热,
异烟肼变质后毒性增大的原因是()A.遇光氧化生成异烟酸铵,使毒性增大
住宅群体空间的基本形式包括( )。A.街坊式 B.行列式 C.点群式 D
两图形分别如图所示。Iy、Iz分别是图(a)、(b)对各自形心轴y、z的惯性矩,
“奇怪的战争”
患者,女性,36岁。因咽痛服磺胺药后,舌背起疱,破溃后疼痛难忍,进食受限。以往曾
施工作业进度计划是根据()施工进度计划来编制的。A.单项工程 B.单位工程
某矿,一工人困伤致右股骨干闭合性骨折,应该如何固定送往医院A.将左下肢和右下肢捆
最新回复
(
0
)