在2014年6月15日的托福閱讀考試中有這樣一道題：雨林中動物傳遞信息的方式。

　　托福真題再現：
　　版本一
　　1，地球早起大氣成分及生物 早起甲烷與二氧化碳占主要地位，沒有氧氣。因為有了會光合作用的細菌，產生了大量氧氣，消耗二氧化碳，提供臭氧層，為當今新生物鐘提供必要環境。
　　版本二
　　有一個講地球最早怎么產生生物的
　　大概有幾點，首先是太陽當時不夠熱，地球當時氣體組成像火山的，主要靠兩種氣體加溫度，似乎一種是二氧化碳另一種是m開頭的不認識
　　那種氣體組成不適合生命也沒什么氧，當時的organism有很大作用，進行光合作用產生氧氣吸收二氧化碳，二氧化碳還有一部分被轉移成非氣態的，這樣就形成了后來的大氣組成
　　氧氣可以形成臭氧層，保護生物不受紫外線輻射，這塊提到了火星等其他星球就沒有臭氧層或者臭氧不夠多blabla不記得了，反正當時生物都去海里了因為水可以吸收紫外線輻射保護它們
　　新東方謝真真老師解析：本文屬于生命起源類型，是托福閱讀資歷很老的話題之一，寫作角度涉及到巴斯德實驗、生命起源的幾種假說，以及過程的描述，同學在閱讀中的難點是要克服對生僻詞匯和背景知識的恐懼心理，這些都可以通過多讀和精讀來實現。
　　參考閱讀：
　　There is no truly "standard" model of the origin of life. But most currently accepted models build in one way or another upon a number of discoveries about the origin of molecular and cellular components for life, which are listed in a rough order of postulated emergence:
　　1. Plausible pre-biotic conditions result in the creation of certain basic small molecules (monomers) of life, such as amino acids. This was demonstrated in the Miller-Urey experiment by Stanley L. Miller and Harold C. Urey in 1953, although it is now generally held that their laboratory conditions did not reflect the original Earth's atmosphere.
　　2. Phospholipids (of an appropriate length) can spontaneously form lipid bilayers, a basic component of the cell membrane.
　　3. The polymerization of nucleotides into random RNA molecules might have resulted in self-replicating ribozymes (RNA world hypothesis).
　　4. Selection pressures for catalytic efficiency and diversity result in ribozymes, which catalyse peptidyl transfer (hence formation of small proteins), since oligopeptides complex with RNA to form better catalysts. Thus the first ribosome is born, and protein synthesis becomes more prevalent.
　　5. Protein out-compete ribozymes in catalytic ability, and therefore become the dominant biopolymer. Nucleic acids are restricted to predominantly genomic use.
　　There are many different hypotheses regarding the path that might have been taken from simple organic molecules to protocells and metabolism. Many models fall into the "genes-first" category or the "metabolism-first" category, but a recent trend is the emergence of hybrid models.
　　The origin of the basic biomolecules, while not settled, is less controversial than the significance and order of steps 2 and 3. The basic chemicals from which life was thought to have formed are commonly held to be methane (CH4), ammonia (NH3), water (H2O), hydrogen sulfide (H2S), carbon dioxide (CO2) or carbon monoxide (CO), and phosphate (PO43-). Molecular oxygen (O2) and ozone (O3) typically are considered to have been either rare or absent.
　　As of 2007, no one had yet synthesized a "protocell" using basic components that would have the necessary properties of life (the so-called "bottom-up-approach"). Without such a proof-of-principle, explanations have tended to be short on specifics. However, some researchers working in this field have argued that a "top-down approach" is more feasible. One such approach involves engineering existing prokaryotic cells with progressively fewer genes, attempting to discern at which point the most minimal requirements for life were reached. The biologist John Desmond Bernal coined the term biopoesis for this process, and suggested that there were a number of clearly defined "stages" that could be recognized in explaining the origin of life.
　　Stage 1: The origin of biological monomers
　　Stage 2: The origin of biological polymers
　　Stage 3: The evolution from molecules to cell
　　Bernal suggested that Darwinian evolution may have commenced early, some time between Stage 1 and 2.