首页
登录
职称英语
When less was known of animals and plants, the discovery of a new species wa
When less was known of animals and plants, the discovery of a new species wa
游客
2025-01-30
13
管理
问题
When less was known of animals and plants, the discovery of a new species was the great object. This is now almost the lowest kind of scientific work. The discovery of a new species as such does not change a feature in the science of natural history. It is merely adding to the enumeration of objects.
We should look rather for the fundamental relations among animals; the number of species we may find is of importance only if they explain the distribution and limitation of different
genera
and families, their relations to each other and to the physical conditions under which they live. The origin of life is the great question of the day. How did the organic world come to be as it is? How did Brazil come to be inhabited by the animals and plants now living there? Who were its inhabitants in past times? What reason is there to believe that the present condition of things in this country is in any sense derived from the past?
The first step in this investigation must be to ascertain the geographical
distribution
of the present animals and plants. Suppose we first examine the Rio San Francisco. The basin of this river is entirely isolated.
Are its inhabitants, like its waters, completely distinct from those of other basins
? Are its species peculiar to itself, and not repeated in any other river of the continent? Extraordinary as this result would seem, I nevertheless expect to find it so. The next water-basin we shall have to examine will be that of the Amazons, which connects through the Rio Negro with the Orinoco. It has been frequently repeated
that
the same species of fish exist in the waters of the San Francisco and in those of Guiana and of the Amazons. At all events, our works on fish constantly indicate Brazil and Guiana as the common home of many species; but this observation has never been made with sufficient accuracy.
Fifty years ago the exact locality from which any animal came seemed an unimportant fact in its scientific history, for the bearing of this question on that of origin was not then perceived. To say that any specimen came from South America was quite enough; to specify that it came from Brazil, from the Amazons, the San Francisco, or the La Plata, seemed a marvelous accuracy in the observers. In the museum at Paris, for example, there are many specimens entered as coming from New York or from Para; but all that is absolutely known about them is that they were shipped from those seaports. Nobody knows exactly where they were collected. All this kind of investigation is far too loose for our present object. Our work must be done with much more precision.
Therefore, my young friends who come with me on this expedition, let us be careful that every specimen has a label, recording locality and date. We must try not to mix the fish of different rivers, even though they flow into each other, but to keep our collections
perfectly
distinct. You will easily see the vast importance of thus ascertaining the limitation of species, and the bearing of the result on the great question of origin. [br] The author views his future work as answering the question________.
选项
A、Can we learn from history?
B、Where did man come from?
C、How many species are there?
D、How did life originate?
答案
D
解析
细节识别。第一段否定了发现新物种的重要性,第二段则明确了工作的重点。第二段列出了四个问题,其核心是为了回答“The origin of life is the great question of the day”,即选项D。
转载请注明原文地址:https://www.tihaiku.com/zcyy/3934950.html
相关试题推荐
Whenlesswasknownofanimalsandplants,thediscoveryofanewspecieswa
Whenlesswasknownofanimalsandplants,thediscoveryofanewspecieswa
Ican’trestrainmyangerwhenIhearofpeoplebeingcrueltoanimals.A、holdon
InmanypartsofEastAfricaatthattime,wildanimalswereso_____thatitwa
Myfriendranafarm,butrefusedtokilltheanimalshehadraisednorotherwis
Whatcausedgreatmigrationsofanimalsandplants?[br][originaltext]Duringt
Whatcausedgreatmigrationsofanimalsandplants?[br][originaltext]Duringt
Whatcausedgreatmigrationsofanimalsandplants?[originaltext]Duringthepas
GlobalWarming:PlantsMayAbsorbMoreCarbonDioxideThanPreviouslyThoughtVo
WhichofthefollowingisNOTtrue?[originaltext]Whileplantsarestillcapable
随机试题
[originaltext]Peoplehavedifferentviewsonwhatchildrenshoulddoatavery
A.速率为v2的各分子的总平动动能与速率为v1的各分子的总平动动能之差 B.速
牛膝的功效是A.既能活血行气,又能利胆退黄 B.既能活血调经,又能引血下行
某房地产开发项目在市场前景好、一般、差时的财务净现值分别为4000万元、1200
沉井基础是在场地条件和技术条件受限制时常常采用的一种深基础形式,其应用范围主要为
公司为增加注册资本而发行新股时,股东有权按照实缴的出资比例认购新股。()
根据不同角度所划分的银行资本中的经济资本()。A.是银行需要保有的最低资本量
选择题要编好题干,也要编好选项,必须注意()。 (A)题干问题明确,避
转导与溶原性转换的共同点是A.以温和噬菌体为媒介 B.转移的遗传物质为供体菌的
银行承兑汇票的承兑银行,应当按照票面金额向出票人收取()的手续费。A:千分之一
最新回复
(
0
)