※ 引述《freezein (....)》之铭言： : 我刚好跳过2/3的JJ没看 囧 : 听力 : 很多记不得了 打记得的 : 其中有一篇是有机生物如何在地球发生 : 有两种解释 1. 从non-organism-->organism : 2.环境造成 : 於是有科学家做了实验 : 模拟了地球形成时的状况 给了水 gas electrity : 发现会渐渐产生organism : 然後把gas当控制变因 发现 还是会产生organism : 最後把electrity当成辨因，发现就不会有organism产生 : 所以推论电是organism产生的主要原因 : 然後就有人批判了 说这个实验的gas跟当时地球形成时的gas不同 : 所以这个结论是错的(有题) 我也是觉得2/3的JJ年代太久远所以跳过没看。不过运气很好，刚好前几天的BBC News 就讲到这个Stanley Miller的经典实验。连结如下： http://news.bbc.co.uk/2/hi/science/nature/7675193.stm 这篇新闻的前段内容几乎跟听力考题完全一样，并继续延伸题目中，最後质疑者认为 Miller实验的化学物质跟地球初期的环境中所含有的物质并不一样﹝这边有考题，此 怀疑并不影响Miller实验的重要性，新闻也提到了﹞。 新闻的重点在於Miller的学生在他过世之後翻箱倒柜找出了Miller当年的实验遗迹， 发现後来他重作了实验，并且添加了其他的化学物质，使其更类似地球初期的火山环 境，并且得到了相同的结果，也就是依然产生有机化合物。 不过我猜考完的人大概也懒得看了，当作是补充教材给以後考试的人当作参考吧。 ============================================================================== BBC News 全文 New spark in classic experiments By Roland Pease BBC Radio Science Unit There's a new spark of life in iconic experiments first done in the 1950s, on the kind of primordial "soup" that may have predated life itself on Earth. Ageing vials of chemicals have been discovered in a Californian lab, surviving samples from the legendary experiments performed by chemist Stanley Miller. They hold evidence that life may have born violently, in erupting volcanoes in the midst of a thunderstorm. Miller was just 22 years old and studying for his PhD when he carried out his original, groundbreaking experiments (under his University of Chicago mentor, Harold Urey). He wanted to test the current ideas for the origin of life, by striking electric sparks in a mixture of gases thought to resemble the atmosphere of the young Earth. When his analysis of the products in the experiments revealed traces of the building blocks of life, amino acids (which combine to make proteins), Stanley Miller became an instant celebrity - though the 1950s newspapers were overstating the case when they claimed he had actually recreated life in the lab. When Stanley Miller died in May last year, his former student, Jeffrey Bada, inherited his materials; including, it turns out, several boxes containing vials of dried samples from those 1950s experiments, and the accompanying notebooks. "We started going through some of the stuff that was piled up in the corner, and here were several little cardboard boxes, taped shut and all dusty, carefully labelled with all of these little vials with dried material from his experiments," Professor Bada, of the University of California, San Diego, told the BBC. Miller's well-known experiments first done in 1952 used water along with methane, ammonia and hydrogen, the kinds of gases then thought to have dominated the Earth's oxygen-free atmosphere more than two billion years ago. His sparks turned the mixture red, then yellow-brown, and made a number of amino acids, including glycine and alanine, commonly found in proteins. But soon after, Miller had revised those experiments by injecting hot steam into the gas mixture, so that conditions resembled those you might find in an erupting volcano. These experiments were the ones that intrigued Jeffrey Bada. Because not long after Miller's original experiments, it became clear the Earth's early atmosphere was nothing like the "reducing" mixture simulated in his apparatus. The first experiments remained iconic in their attempt at simulating pre-biotic chemistry, but became irrelevant in detail. But conditions locally in volcanoes, says Professor Bada, might not have been so different. The trouble was, Miller published only the sketchiest of details of those tests, and the apparatus was lost. It had looked like a dead end, until those dusty boxes turned up with their 200 vials. "We started sorting through these, and lo and behold, we found a whole collection, almost a complete collection, of the extract samples from the volcanic experiments. And so we just went at it, using the state-of-the-art techniques we have today and analysed these samples. "We found not only did these make more of certain amino acids than in the classic experiment, but they made a greater diversity of amino acids." Miller, using the old methods, had found five amino acids; Jeffrey Bada and his teams tracked down 22. What is more, the overall chemical yields were often higher than in the first set of experiments - the mixture appeared to be more fertile. Professor Bada points out that today, almost all volcanic eruptions are accompanied by violent electric storms. The same could have been true on the young Earth. "What we suggest is that volcanoes belched out gases just like the ones Stanley had used, and were immediately subjected to intense volcanic lightning. "And so each one of those volcanoes could have been a little, local prebiotic factory. And so all of that went into making the material that we refer to as the prebiotic soup." That material could then have been washed down the flanks of volcanoes into pools or coastal bays, where the building blocks of life might have kick-started evolution. Jeffrey Bada and colleagues report their latest work in the journal Science. -- 　　　　　　　　　逻辑无助於科学。 　　　　　　　　　　　　　　法兰西斯‧培根 --

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