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
2023-12-31
68
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] According to the author, the focus of the research should be on________.
选项
A、the origins and related issues of animals and plants
B、the number of animals and plants
C、a scientific study of living things
D、the physical conditions under which animals live
答案
A
解析
细节识别。第二段首先提到“should look rather for the fundamental relations”,然后是“genera and families,their relations to each other…The origin of life is the great question of the day”,这些表述与选项A一致。
转载请注明原文地址:https://tihaiku.com/zcyy/3320388.html
相关试题推荐
Ifindthatmostchildren’sbooksareaboutboys,menandmaleanimals,andmost
Whenbotheredbyotheranimalsorhumans,somespeciesofhornedlizardswillpo
Container-grownplantscanbeplantedatanytimeoftheyear,but______inwin
Container-grownplantscanbeplantedatanytimeoftheyear,but______inwin
Asadefenseagainstair-pollutiondamage,manyplantsandanimals______asubs
Humanbeingsaresuperiortoanimalsthattheycanuselanguageasatoolofcom
Nowwhicharetheanimalsreallytobepitiedincaptivity?First,thosecle
Nowwhicharetheanimalsreallytobepitiedincaptivity?First,thosecle
Nowwhicharetheanimalsreallytobepitiedincaptivity?First,thosecle
Nowwhicharetheanimalsreallytobepitiedincaptivity?First,thosecle
随机试题
FoodandHealthVocabularyandExpressionsfoodborneillnessacuteadverse
Theconceptofpersonalchoiceinrelationtohealthbehaviorsisanimportan
Sometimesthestudentmaybeaskedtowriteabouthis_______toacertainbook
Theplaceofthechildinsocietyhasvariedforthousandsofyearsandhas
患者,女,61岁,左耳流脓1年,脓稀不臭。检查发现左鼓膜紧张部穿孔。 此时考虑
在小学数学材料中,面积公式的推导过程包含的主要数学思想是()。A.函数与方程思想
变电运维班运维计划应包括()及日常维护、设备消缺等工作内容。倒闸操作$;$
一位幼儿教师在工作中能够做到:兢兢业业,不干出点样不甘心;无私奉献,用花和果来成
调节体内激素平衡从而治疗肿瘤的常用药物不包括A.来曲唑 B.他莫昔芬 C.托
一定时期货币供应量是600,货币流通速度是2,商品的交易数量是400,则价格总水
最新回复
(
0
)