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
12
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] It can be inferred from the passage that the author considers Fisher’s work to be ______.
选项
A、definitive and thorough
B、inaccurate but popular, compared with Hamilton’s work
C、accurate, but trivial compared with Hamilton’s work
D、admirable, but not as up-to-date as Hamilton’s work
答案
D
解析
转载请注明原文地址:https://tihaiku.com/zcyy/4047910.html
相关试题推荐
Dogsaresocialanimalsandwithoutpropertraining,theywillbehavelikew
Dogsaresocialanimalsandwithoutpropertraining,theywillbehavelikew
Dogsaresocialanimalsandwithoutpropertraining,theywillbehavelikew
Dogsaresocialanimalsandwithoutpropertraining,theywillbehavelikew
Dogsaresocialanimalsandwithoutpropertraining,theywillbehavelikew
Dogsaresocialanimalsandwithoutpropertraining,theywillbehavelikew
Cananimalshaveasenseofhumor?SallyBlanchard,publisherofanewslette
Theearthiswitnessinganurbanrevolution,aspeopleworldwidecrowdinto
Theearthiswitnessinganurbanrevolution,aspeopleworldwidecrowdinto
Theearthiswitnessinganurbanrevolution,aspeopleworldwidecrowdinto
随机试题
下列关于集合竞价的说法,正确的有()。A、集合竞价采用最大成交量原则B、高于集合竞价产生的价格的买入申报全部成交C、低于集合竞价产生的价格的卖出申报
车辆进入山区道路后,要特别注意“连续转弯”标志,并主动避让车辆及行人,适时减速和
在运输业总产值的计算中,旅客托运的行李包裹收入从性质上说属于( )。A.货运收
A.急性血肿 B.亚急性血肿 C.梗死 D.水肿 E.慢性血肿TWI和T
在现场抢救急性中毒患者时,护士首先应采用的排出毒物的方法是A.造瘘口洗胃 B.
(2011年)《测绘计量管理行办法》规定,测绘单位使用未经检定,或者检定不合格或
1994-10.任脉的终点是 A.目内侧B.目眶下C.口唇D.上
国家股是指有权代表国家投资的部门或机构以国有资产向公司投资形成的股份,包括()。
证监会在其2010年《投资顾问业务暂行规定》中,把()作为证券公司有偿专
(2018年真题)根据《民法典》规定,法人成立须具备的条件有( )。A.有自己
最新回复
(
0
)