首页
登录
职称英语
As every schoolboy knows, insects pollinate flowers, while birds and mammals
As every schoolboy knows, insects pollinate flowers, while birds and mammals
游客
2023-10-16
40
管理
问题
As every schoolboy knows, insects pollinate flowers, while birds and mammals disperse seeds by eating fruits or transporting burs on their feathers and fur. These are examples of co-evolution, a phenomenon first described by Charles Darwin in The Descent of Man, and Selection in Relation to Sex, published in 1871.
Co-evolution, in which two species have evolved together in response to adaptations that each has imposed on the other, can be extremely subtle. For instance, some animals may help to transfer pollen from one plant to another without acting directly as the carrier themselves. Instead, they make it easier for the pollen to be dispersed by other creatures. Mats Olsson and Richard Shine, of the University of Sydney, and Elisabeth Bak-Olsson, of the University of Gothenburg in Sweden, have discovered, apparently for the first time, such a mutually beneficial arrangement between a reptile and a plant.
For most of the year the Tasmanian snow skink lizard confined to mountain tops in that island is catholic in what it eats. But when the honey-bush is in bloom, the skinks make a point of tearing off the tough, red petals that enclose the rest of the flower. They chew them to extract the nectar and spit out what is left. At first sight, this skink-savaging may not seem all that helpful to the honey- bush. But it is. It exposes the reproductive parts of the flowers, thereby allowing pollinating insects to get at them. Dr. Olsson and his colleagues found that flowers with the petals left intact never produced seed. But, according to their paper in the Biological Journal of the Linnean Society, 87% of flowers with the petals torn off did so.
To check that it was the skinks alone that were the plants’ little helpers, the researchers placed cages around some honey-bushes. Virtually all of the petals were removed from the flowers on bushes without cages. Only 16% of the caged bushes had their petals ripped off, possibly by high winds battering them.
Dr Olsson found no evidence of pollen being carried on a skink and so concluded that the lizards play no role in transporting honey-bush pollen from one flower to another. But he did see a range of insects: wasps, flies, bumble-bees and others feeding from honey-bush flowers that had no petals covering them. Without the petals removed, it was impossible for insects to do any pollinating.
SUMMARY:
Co-evolution is【51】described by Charles Darwin in The Descent of Man. In the process of co-evolution, two species may have to respond to adaptations they have imposed on each other.
For example, some animals may not carry.【52】from one plant to another. They may help by making it easier for other creatures to disperse the pollen from one plant to another. Such an arrangement seems【53】to both species. In Tasmania, the skink lizards chew the red petals of【54】and spit out what is left. In doing so, they expose the reproductive parts of the flower and enable pollinating insects to reach them. It was discovered that 87% of these flowers produced seeds. Conversely, flowers with petals remaining【55】never did. [br]
选项
答案
a phenomenon
解析
(由原文These are examples of co-evolution,a phenomenon first described by Charles Darwin可知答案。)
转载请注明原文地址:https://tihaiku.com/zcyy/3102908.html
相关试题推荐
Whydosomemammalschoosetobeawakeatnight?[originaltext]Anewstudyfinds
Mygardenhaslargetrees.Mygardenhasflowerswhichsmelllovelywheninbloo
-WhatamIgoingtodoaboutapresentforCarol?-You______someflowers.A、mig
Mygardenhaslargetrees.Mygardenhasflowerswhichsmelllovelywheninbloo
Someofthesensesthatweandotherterrestrialmammalstakeforgrantedar
Someofthesensesthatweandotherterrestrialmammalstakeforgrantedar
Aseveryschoolboyknows,insectspollinateflowers,whilebirdsandmammals
Aseveryschoolboyknows,insectspollinateflowers,whilebirdsandmammals
Aseveryschoolboyknows,insectspollinateflowers,whilebirdsandmammals
Aseveryschoolboyknows,insectspollinateflowers,whilebirdsandmammals
随机试题
Thecostofstagingtheyear2000OlympicsinSydneyisestimatedtobeast
Bywritingthispassage,thewriterintendstotellusthat______.[br]Theamou
不属于承压水基本特点的是()。A.没有自由表面 B.受水文气象因素、人文因
必须按照国务院卫生行政部门的有关规定,严格执行消毒隔离制度,防止发生内感染和医源
关于损失厌恶,下列说法中正确的有( )。 Ⅰ损失厌恶是指人们对财富的减少比对
阿司匹林严重中毒时,正确的处理措施是A.静脉滴注大剂量维生素C B.口服氯化铵
消防技术服务机构对某商场内设置的湿式自动喷水灭火系统进行检测,现场询问得知,湿
( )又称稳定性或可信性,是指一个人在同一心理测量中几次测量结果的一致性。A.
在勘察设计招标文件中,以下( )属于发包人要求的内容。A.投标人须知 B.评标
某项目合同价1000万元,合同约定固定系数0.2。2009年5月
最新回复
(
0
)