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
Single mums are better at raising their kids than two parents—at least in the bird world. Mother zebra finches have to work hard
Single mums are better at raising their kids than two parents—at least in the bird world. Mother zebra finches have to work hard
admin
2011-01-10
43
问题
Single mums are better at raising their kids than two parents—at least in the bird world. Mother zebra finches have to work harder and raise fewer chicks on their own, but they also produce more attractive sons who are more likely to get a mate.
The finding shows that family conflict is as important an evolutionary driving force as ecological factors such as hunting and food supply. With two parents around, there’s always a conflict of interests, which can have a detrimental effect on the quality of the offspring.
In evolutionary terms, the best strategy for any parent in the animal world is to find someone else to care for their offspring, so they can concentrate on breeding again. So it’s normal for parents to try to pass the buck to each other. But Ian Hartley from the University of Lancaster and his team wondered how families solve this conflict, and how the conflict itself affects the offspring.
To find out, they measured how much effort zebra finch parents put into raising their babies. They compared single females with pairs, by monitoring the amount of food each parent collected, and removing or adding chicks so that each pair of birds was raising four chicks, and each single mum had two--supposedly the same amount of work.
But single mums, they found, put in about 25 percent more effort than females rearing with their mate. To avoid being exploited, mothers with a partner hold back from working too hard if the father is being lazy, and it’s the chicks that pay the price. "The offspring suffer some of the cost of this conflict," says Hartley.
The cost does not show in any obvious decrease in size or weight, but in how attractive they are to the opposite sex. When the chicks were mature, the researchers tested the "fitness" of the male offspring by offering females their choice of partner. Those males reared by single mums were chosen more often than those from two-parent families.
Sexual conflict has long been thought to affect the quality of care given to offspring, says zoologist Rebecca Kilner at Cambridge University, who works on conflict of parents in birds. "But the experimental evidence is not great. The breakthrough here is showing it empirically."
More surprising, says Kilner, is Hartley’s statement that conflict may be a strong influence on the evolution of behaviour, clutch size and even appearance. "People have not really made that link," says Hartley. A female’s reproductive strategy is usually thought to be affected by hunting and food supply. Kilner says conflict of parents should now be taken into account as well.
What is the relationship between paragraph 4 and paragraph 5?
选项
A、Cause and effect.
B、Experiment and result.
C、Problem and solution.
D、Topic and comment.
答案
B
解析
转载请注明原文地址:https://kaotiyun.com/show/y9cO777K
本试题收录于:
NAETI中级口译笔试题库外语翻译证书(NAETI)分类
0
NAETI中级口译笔试
外语翻译证书(NAETI)
相关试题推荐
Norevolutionsintechnologyhaveasvisiblymarkedthehumanconditionasthoseintransport.Movinggoodsandpeople,theyhav
TheKyotoProtocolhasbeendesignedto______theglobalenvironmentalproblems.
Itwastwoyearsagotodaythatthehuntingbancameintoforce,supposedlyendingcenturiesoftradition.However,thelawhas
ThefirstrecordeduseofnaturalgastolightstreetlampsitwasinthetownofFrederick,NewYork,in1825.
Ithinkyoucantakea(n)______languagecoursetoimproveyourEnglish.
Intheadvancedcourseofourtraining,studentsmusttakeobjectivetestsatmonthly
Ourcompanyhasbeenmadeoneofthelargestmanufacturersinthefieldofchemicalindustry.
下面你将听到的是一段有关矿产开发的讲话。中国经济高速发展,需要大量的矿产品及相关的能源与原材料加工制品。每年消耗的矿石量达60多亿吨,位居世界前列。中国政府为实现经济的可持续发展,在矿产资源勘查、开发领域制定了一系列的法律、法规和政策,
下面你将听到的是一段有关中美交流的讲话。中美两国建交以来,人民之间的交往不断扩大。两国已缔结了33对友好省州和123对姊妹城市。去年,到中国旅游的美国人多达13l万人次。中国赴美探亲、求学、经商的有44万人次。中国有超过18万人曾在美国留学,目前
继续教育向成人开设的课程包括,职业课程和休闲娱乐课程。即要么与个人工作相关,要么纯粹出于兴趣和娱乐。如今在英国,有数百万全日制和业余制的学生在继续教育学院和夜校学习,年龄从16到80岁不等。其中部分选择一些加强某项技能的专业课程,并为文凭而努力。还有人回到
随机试题
脊髓灰质炎的好发年龄
下列属于财务费用的是()
女,30岁,已婚6年未孕,近3年出现痛经,经量增多,经期延长,性交痛,B超提示左附件区直径5cm之无回声区,内有点状强回声,与子宫粘连。确诊的检查是
患者,男,16岁。煤气中毒后1个月,突发昏仆,肢体抽搐,口吐涎沫,约5分钟后神志转清,自述疲乏,舌苔白腻,脉象弦滑。诊为
A.干酪样坏死B.脂肪坏死C.坏疽D.纤维素样坏死E.液化性坏死产后子宫内膜炎()
下列属于编制建设项目信息管理手册的内容的是()。
在进口货物收发货人或其代理人不在场的情况下,海关不可以自行开拆货物进行查验。()
( )是发行人发行股票时,就发行中的有关事项向公众作出披露,并向非特定投资人提出购买或销售其股票的要约邀请性文件。
景区导游服务的核心工作是()。
CDMA系统中使用的多路复用技术是(62)。我国自行研制的移动通信3G标准是(63)。
最新回复
(
0
)