时间:2019-02-24 作者:英语课 分类:英语听力文摘 English Digest


英语课

The Most Successful Species on Earth

地球上最成功的物种


For many scientists, a species’ success is measured by sheer numbers. In that case, the most successful species known to man is a type of bacterium known as S-A-R-11, or SAR-11 for short. Scientists estimate that there are two-hundred and forty times a billion billion billion SAR11 cells floating around in the oceans. Now that makes six-billion humans sound like a mere 1 handful.


SAR11 bacteria are known for their ability to transform one substance into another, which is why they are such an important part of the Earth’s chemical cycles. Although scientists are still uncertain about SAR11′s specific role, it appears to produce carbon dioxide using the oxygen and carbon from organic matter that’s derived 2 from photosynthesis 3. Scientists speculate that SAR11 plays a major role in the way the ocean’s surface acts as a giant carbon pump that removes carbon dioxide from the atmosphere.


The catch is that SAR11 is what is known as an uncultured organism, which means that scientists haven’t been able to cultivate it under laboratory conditions. This requires scientists to develop pretty indirect genetic 4 methods just to be able to study SAR11 cultures. Now that this technology is available, scientists are sequencing the SAR11 genome in order to figure out exactly what kinds of carbon it uses, and why it’s so successful at ocean living.








对很多科学家来说,一个物种的成功完全取决于数量。如果是那样是话,为人类所知的最成功的物种就是一种简称“SAR-11”的细菌。科学家们估计海洋中的SAR11细胞的数量超过2 x 10的28次方个。那让60亿人类听起来屈指可数。

SAR11细菌以其转换物质的能力为人所知。而这也使得它们成为地球化学循环中重要的部分。尽管科学家不能确定SAR11的具体作用。但它似乎可以使来自于光合作用的氧气和有机物种的碳发生作用,产生二氧化碳。科学家推测SAR11在海洋表面扮演着重要的作用,作为一个巨大的碳泵移除空气中的二氧化碳。


但目前SAR11是为培养生物,也就是说科学家不能在实验室里培养出这种细菌。因此需要科学家们研制出间接遗传方法,来研究SAR11。既然这项技术可用,科学家为了弄清楚究竟SAR11用的是哪种碳以及为什么它会如此的成功在海洋中生活,正在排序它的基因组。




 



adj.纯粹的;仅仅,只不过
  • That is a mere repetition of what you said before.那不过是重复了你以前讲的话。
  • It's a mere waste of time waiting any longer.再等下去纯粹是浪费时间。
vi.起源;由来;衍生;导出v.得到( derive的过去式和过去分词 );(从…中)得到获得;源于;(从…中)提取
  • Many English words are derived from Latin and Greek. 英语很多词源出于拉丁文和希腊文。 来自《简明英汉词典》
  • He derived his enthusiasm for literature from his father. 他对文学的爱好是受他父亲的影响。 来自《简明英汉词典》
n.光合作用
  • In apple trees photosynthesis occurs almost exclusively in the leaves.苹果树的光合作用几乎只发生在叶内。
  • Chloroplasts are the structures in which photosynthesis happens.叶绿体就是光合作用发生的地方。
adj.遗传的,遗传学的
  • It's very difficult to treat genetic diseases.遗传性疾病治疗起来很困难。
  • Each daughter cell can receive a full complement of the genetic information.每个子细胞可以收到遗传信息的一个完全补偿物。
学英语单词
adenosine deaminase
All-optical switch
amplitude transmitter
atmosphere distillation
bammed
be lost
byte space
cargo-bay
combination-bar operating spring
complete character input
computer draft
Corn-soy-milk
covarimin
cruths
cup washer
damage correction
diallyl (o-)phthalate(DAP)
differential monitor
dioctylmethylenebisphosphonate
druggist rubber sundries
dry combustion chamber boiler
dupont test paper
eagleberger
eleven pointer
equina
exit turn
fast charging
feeler blade
field-conventicle
figaroes
folded and gathered
Gallipoli
gasdynamics of detonation
given notice
Grant's Tomb
ground shells
half-English
hammerhead crane
Harrier jump jet
Hastings, Battle of
hexagonia tenuis
high-speed automatic transmitter
indirect injection
inopportunist
introcession
iodosulfate
laryngeal chondromalacia
ligg. tarsometatarsea dorsalia
line intersection method
little-leaf symptom
loungerooms
Lytton, Edward George Earle Lytton Bulwer-,lst Baron Lytton
magnetically sensitive recording paper
magnetizing by induction
major synchronization point
materials account
military-planes
mohela
multiple threaded screw
Nepalese rupee
nosegay
number of locomotives in service
outer lacquered can
Overall Payments Agreement
Pabst Brewing Company
page ranking
pimco
pizza bone
plastic compression
predating
principal derivative
pseudomorph by infiltration
public savings
purse string suture
radar dish
Rakaca-patak
Reevesia orbicularifolia
Reichenfels
round ligament of bladder
sample recovery
sea colander
segmentalised
sense data
shatners
shingle block structure
siphunculate
sloughful
solsequium
Spongillan
sweeing
swingle-hand
telechelic polymer
true homing
tube expansion
unpolarizing
unruly child
UPU
valourous
verbalised
weight concentrated in the back
well-cared-fors