2012年2月25日托福考试出现的是2010年12月18日的北美考题，新东方葛旭老师参考20121218NA的考试回忆，找到两篇文章的出处：第一篇文章“生命起源”在维基百科上可以拼出全文；第二篇文章“蜜蜂大脑与分工”则通过“公共科学图书馆”（PLoS）找到2010年11月2日发表的当时新研究成果，同2010年12月18日考试时间吻合，故认定是原始出处。
PASSAGE 1 生命起源 Origin of Life
第一段：海洋起源论；
第二段：该理论遭到质疑。
第三段：有机分子是在宇宙中碰撞产生的，在低温条件下稳定；
第四段：有机分子负载到陨石上落在地球上的过程。
第五段：海底热泉说，热泉产生富含生命所需元素的泉水；
第六段：热泉温度高，小分字亦不稳定。
根据此整理的回忆结果，可以看出一共有三个理论，即海洋起源、星际起源以及海底热泉起源。（具体的学术名称还有待考证）
在这里针对相对较难的后两者进行背景扩展与还原，情况如下（参考文章见尾注）：
星际起源说：
“An alternative to Earthly abiogenesis is the hypothesis that primitive life may have originally formed extraterrestrially, either in space or on Mars, a nearby planet.
Organic compounds are relatively common in space, especially in the outer solar system where volatiles are not evaporated by solar heating. Comets are encrusted by outer layers of dark material, thought to be a tar-like substance composed of complex organic material formed from simple carbon compounds after reactions initiated mostly by irradiation by ultraviolet light. It is supposed that a rain of material from comets could have brought significant quantities of such complex organic molecules to Earth.
An alternative but related hypothesis, proposed to explain the presence of life on Earth so soon after the planet had cooled down, with apparently very little time for prebiotic evolution, is that life formed first on early Mars. Due to its smaller size Mars cooled before Earth (a difference of hundreds of millions of years), allowing prebiotic processes there while Earth was still too hot. Life was then transported to the cooled Earth when crustal material was blasted off Mars by asteroid and comet impacts. Mars continued to cool faster and eventually became hostile to the continued evolution or even existence of life (it lost its atmosphere due to low volcanism); Earth is following the same fate as Mars, but at a slower rate.”
海底热泉说：The Deep Sea Vent Theory
The deep sea vent, or hydrothermal vent, theory for the origin of life on Earth posits that life may have begun at submarine hydrothermal vents, where hydrogen-rich fluids emerge from below the sea floor and interface with carbon dioxide-rich ocean water. Sustained chemical energy in such systems is derived from redox reactions, in which electron donors, such as molecular hydrogen, react with electron acceptors, such as carbon dioxide (see iron-sulfur world theory).
扩展阅读: Iron-Sulfur World Theory
注：托福原文中提到了“硫化铁”对于生命形成的影响。看起来是“海底热泉说”中重要的一部分，因此在这里将这篇扩展阅读放在这里，供想进一步了解“热泉说”的同学了解背景。
“The theory proposes that early life may have formed on the surface of iron sulfide minerals, hence the name. It was developed by retrodiction from extant biochemistry in conjunction with chemical experiments.”
“The fundamental idea of the origin of life according to the iron-sulfur world theory can be simplified in the following brief characterization: Pressurize and heat a water flow with dissolved volcanic gases (e.g. carbon monoxide, ammonia and hydrogen sulfide) to 100 °C. Pass the flow over catalytic transition metal solids (e.g. iron sulfide and nickel sulfide). Wait and locate the formation of catalytic metallo-peptides. Some crucial aspects of this theory have been confirmed experimentally.”
PASSAGE 2 蜜蜂大脑 Honeybee Brain
蜜蜂分工是由大脑中基因与激素决定的。
本文是2010年12月18日出现在托福考试中，经过搜索，发现本文基于同年11月2日发布在“公共科学图书馆”（PLoS）中The Honey Bee Epigenomes: Differential Methylation of Brain DNA in Queens and Workers一文编纂而成。在这里将原文的摘录与结论部分放在这里，供各位参考。因学术成果，请转载时注意同时转载出处，尊重版权。
ABSTRACT
In honey bees (Apis mellifera) the behaviorally and reproductively distinct queen and worker female castes derive from the same genome as a result of differential intake of royal jelly and are implemented in concert with DNA methylation. To determine if these very different diet-controlled phenotypes correlate with unique brain methylomes, we conducted a study to determine the methyl cytosine (mC) distribution in the brains of queens and workers at single-base-pair resolution using shotgun bisulfite sequencing technology. The whole-genome sequencing was validated by deep 454 sequencing of selected amplicons representing eight methylated genes. We found that nearly all mCs are located in CpG dinucleotides in the exons of 5,854 genes showing greater sequence conservation than non-methylated genes. Over 550 genes show significant methylation differences between queens and workers, revealing the intricate dynamics of methylation patterns. The distinctiveness of the differentially methylated genes is underscored by their intermediate CpG densities relative to drastically CpG-depleted methylated genes and to CpG-richer non-methylated genes. We find a strong correlation between methylation patterns and splicing sites including those that have the potential to generate alternative exons. We validate our genome-wide analyses by a detailed examination of two transcript variants encoded by one of the differentially methylated genes. The link between methylation and splicing is further supported by the differential methylation of genes belonging to the histone gene family. We propose that modulation of alternative splicing is one mechanism by which DNA methylation could be linked to gene regulation in the honey bee. Our study describes a level of molecular diversity previously unknown in honey bees that might be important for generating phenotypic flexibility not only during development but also in the adult post-mitotic brain.
Author Summary
The queen honey bee and her worker sisters do not seem to have much in common. Workers are active and intelligent, skillfully navigating the outside world in search of food for the colony. They never reproduce; that task is left entirely to the much larger and longer-lived queen, who is permanently ensconced within the colony and uses a powerful chemical influence to exert control. Remarkably, these two female castes are generated from identical genomes. The key to each female's developmental destiny is her diet as a larva: future queens are raised on royal jelly. This specialized diet is thought to affect a particular chemical modification, methylation, of the bee's DNA, causing the same genome to be deployed differently. To document differences in this epigenomic setting and hypothesize about its effects on behavior, we performed high-resolution bisulphite sequencing of whole genomes from the brains of queen and worker honey bees. In contrast to the heavily methylated human genome, we found that only a small and specific fraction of the honey bee genome is methylated. Most methylation occurred within conserved genes that provide critical cellular functions. Over 550 genes showed significant methylation differences between the queen and the worker, which may contribute to the profound divergence in behavior. How DNA methylation works on these genes remains unclear, but it may change their accessibility to the cellular machinery that controls their expression. We found a tantalizing clue to a mechanism in the clustering of methylation within parts of genes where splicing occurs, suggesting that methylation could control which of several versions of a gene is expressed. Our study provides the first documentation of extensive molecular differences that may allow honey bees to generate different phenotypes from the same genome.
PASSAGE 3 植物的地区间的分布差别为何比动物小
三个原因：
1.植物出现时间较早，在地球板块分开前已经传播到各个大陆；
2.植物灭绝率比动物低；
3.即使大陆漂移分开植物仍可以传播，举了夏威夷上两百多种植物的例子，而动物则不能
这一篇的原文线索很难还原。第一个原因（关于地球板块），可参考以下关键词：
Biomass; biodiversity; plant distribution; plant dispersal; continental drift
另外，TPO的The Arrival of Plant The Arrival of Plant Life in Hawaii可以帮助理解夏威夷植物的理解。
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Chang, Kenneth (2009-08-18). "From a Distant Comet, a Clue to Life". Space & Cosmos (New York Times): p. A18. Retrieved 2009-08-19.
Lane, Nick (2010) "Life Acending: the 10 great inventions of evolution"
Wächtershäuser, Günter (2007). "On the Chemistry and Evolution of the Pioneer Organism". Chemistry & Biodiversity 4 (4): 584-602.
Lyko F, Foret S, Kucharski R, Wolf S, Falckenhayn C, et al. (2010) The Honey Bee Epigenomes: Differential Methylation of Brain DNA in Queens and Workers. PLoS Biol 8(11): e1000506. doi:10.1371/journal.pbio.1000506
