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地球上的哺乳动物之所以能够让自己长得更庞大,并掌握对地球的统治权,这在很大程度上依赖于2亿5百万前与5千万年前地球大气层中氧气含量的两次大的增长。以上观点并非无稽之谈,这是美国新泽西州罗特格斯大学海洋与海岸科学研究所的保罗·法尔科斯基教授与其同行经过长期研究后得出的结论。2005年9月30日,著名的美国《科学》周刊发表了法尔科夫斯基小组的这一研究成果。法尔科夫斯基小组通过分析海底原始沉积物中碳和硫的同位素记录,计算出过去数亿年内大气中的氧含量,结果发现,6亿年的大气氧含量约为20%,与现在相近,直到4亿年前一直相当稳定。大约3亿年前,氧含量突然升高到30%,随后在2.4亿前骤降到12%。到了5千万年前,氧气水平回升到17%。到4千万年前,这一含量达到了23%。现在,大气中氧含量达到了21%。研究人员在报告中说,大气中氧气含量的上升,对大型动物的进化起到了某种促进作用。法尔科夫斯基说:“更多的氧气应该有益于哺乳动特的进化。哺乳动物将食物转化为能量的效率要比爬虫类动物4到6倍,因此,它们需要较高的氧气浓度使肌肉有效地工作。此外,较大的哺乳
The reason why mammals on Earth are able to grow bigger and take control of the earth depends largely on the two to five million years ago the oxygen content of the Earth’s atmosphere was 50 million years ago. The next largest increase. The above point of view is not nonsense. This is the conclusion made by Professor Paul Farkoski of the Institute of Marine and Coastal Sciences at Rutgers University in New Jersey after a long period of research. On September 30, 2005, the famous American “Science” weekly published the research results of the Falkovsky group. The Falkovsky team calculated the oxygen content in the atmosphere over the past several hundred million years by analyzing the isotopic records of carbon and sulfur in the original sediments of the seabed. It was found that the atmospheric oxygen content of about 600 million years was about 20%. Similar, until 400 million years ago has been quite stable. About 300 million years ago, the oxygen content suddenly rose to 30%, then dropped to 12% before 240 million. By 50 million years ago, oxygen levels have risen to 17%. To 40 million years ago, this content reached 23%. The oxygen content in the atmosphere now reaches 21%. The researchers said in the report that the increase in oxygen content in the atmosphere has promoted the evolution of large animals. Falkovsky said: "More oxygen should be beneficial to the evolution of mammals. Mammals convert food to energy four to six times more efficiently than reptiles, so they need higher oxygen concentrations. Makes muscles work effectively. In addition, larger breastfeeding