首页
登录
职称英语
[originaltext] When I tell people what my particular branch of science is, I
[originaltext] When I tell people what my particular branch of science is, I
游客
2023-12-22
24
管理
问题
When I tell people what my particular branch of science is, I often get funny looks. In a way, I understand because astrobiology is the study of life on other planets. Well, obviously, life has not been discovered on other planets, which would appear to make astrobiology a science without a subject! However, everything we know about life on our own planet suggests we have to try to understand if there are any universal requirements for life to evolve, as well as the processes involved in evolution. Consequently, scientists are deeply interested in the beginnings of life on Earth. Once we know more about what happened on home ground, as it were, we will be in a better position to understand any life forms we may one day find on other planets.
When most people think of extra-terrestrial life, they conjure up images of so-called "higher" life forms: they imagine humanoid creatures or bizarre and probably dangerous animals of some kind. But if we consider the whole history of life on Earth, a very different picture emerges. For billions of years the only forms of life on the planet were organisms consisting of single cells. It was only about 550 million years ago that the seas suddenly became filled with a whole array of multicellular life.
So how do humans fit into this time frame? Well, human-like creatures first appear in the fossil record about five or so million years ago: in geological terms, this is just a blink of an eye compared to the long history of life on Earth. And Homo sapiens, our own species, has only been around for about 130,000 years. The point is if we do find life on other planets, it will almost certainly be relatively simple, of the sort that populated the Earth for most of its existence so far.
And of course, we must be prepared for these life forms to look very different from life on Earth. We must not forget that many modern life forms came about as a result of chance, their fate shaped by floods, continental drift and comet or meteor strikes. It is interesting to reflect that if a giant asteroid had not hit the Earth and wiped out the dinosaurs, they might still be ruling the planet and we might never have evolved.
Question No. 16 Which of the following does astrobiology study?
Question No. 17 When telling people what branch of science he studies, why does the speaker often get funny looks?
Question No. 18 With what life forms did the seas suddenly become filled some 550 million years ago?
Question No. 19 For how long has Homo sapiens, our own species, has been existing on Earth?
Question No. 20 Many modern life forms came about as a result of a series of chance factors. Which of the following is NOT one of these factors mentioned in the talk?
选项
A、Organisms of single cells.
B、Humanoid creatures.
C、Multi-cellular organisms.
D、Bizarre or perhaps dangerous animals.
答案
C
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3295119.html
相关试题推荐
Ifpeoplecannotaffordtobuytheirownhouse,theycanrentpropertyfromapr
Thepresentsituationofpeople’sabnormalbehaviorsspeaksvolumesforthefact
Whereanypeoplehavemadeatemporaryapproachtosuchacharacter,ithasbeen
Thereportercomparesahusbandtoaparticularlytrickymusicalinstrument,one
Modernindustrialsocietygrantslittlestatustooldpeople.Infact,such
Modernindustrialsocietygrantslittlestatustooldpeople.Infact,such
Modernindustrialsocietygrantslittlestatustooldpeople.Infact,such
Wheneverwehearofanaturaldisaster,wefeelsympathetictothepeopletobe
ThehappiestpeopleintheworldmayliveinScandinavia,anewstudysugges
ThehappiestpeopleintheworldmayliveinScandinavia,anewstudysugges
随机试题
TreesTomany,thewordtreesevo
Musicians—fromkaraokesingerstoprofessionalviolinplayers—arebetterabl
()等特种作业人员,必须按照国家有关规定经过专门的安全作业培训,并取得特种作业
下列关于反向购买的表述中,不正确的有( )。A.反向购买是同一控制下企业合并
人类白化病是常染色体隐性遗传病。某患者家系的系谱图如下,显性基因为A,隐性基因为
总需求曲线向下方倾斜的原因是()。A.随着价格水平的下降,居民的实际财富
关于圆癣的描述,以下哪项不正确A:好发于长夏高温、潮湿季节 B:好发于面部、躯
租赁合同中,租赁期间届满,当事人可以续订租赁合同,但约定的租赁期限自续订之日起不
许又新提出的心理健康标准包括()。多选A.体验标准 B.操作标准 C.
男,50岁。幽门梗阻持续胃肠减压半个月,每日10%葡萄糖2500mL,5%葡萄糖
最新回复
(
0
)